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Fermentation, Volume 8, Issue 6 (June 2022) – 49 articles

Cover Story (view full-size image): The production of odd-chain fatty acids (OCFA)-enriched lipids via fermentation using a genetically engineered Yarrowia lipolytica strain was investigated. The major fatty acid produced was the cis-9-heptadecenoic acid (C17:1). Its biosynthesis was optimized using a central composite design. The optimal responses maximizing cell density (optical density at 600 nm) and C17:1 content (%) in lipids were found using 52.4 g/L sucrose, 26.9 g/L glycerol, 10.4 g/L sodium acetate, 5 g/L sodium propionate, and 4 g/L yeast extract. Under these conditions, in a 5 L scale bioreactor, the respective contents of lipids and OCFA in culture medium were 2.52 ± 0.05 and 1.50 ± 0.05 g/L after 96 h fermentation. View this paper
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12 pages, 1663 KiB  
Article
Rheological Properties of Goat Milk Coagulation as Affected by Rennet Concentration, pH and Temperature
by Marina Hovjecki, Zorana Miloradovic, Irena Barukčić, Marijana Blažić and Jelena Miocinovic
Fermentation 2022, 8(6), 291; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060291 - 20 Jun 2022
Cited by 4 | Viewed by 2585
Abstract
Various factors affect rennet coagulation and consequently cheese yield, but the subject of research has been mainly the cow milk. For the purpose of goat cheese production optimization, this paper investigated the influence of enzyme concentration (0.01–0.054 g/L), pH (6.5–6.1) and temperature (27–35 [...] Read more.
Various factors affect rennet coagulation and consequently cheese yield, but the subject of research has been mainly the cow milk. For the purpose of goat cheese production optimization, this paper investigated the influence of enzyme concentration (0.01–0.054 g/L), pH (6.5–6.1) and temperature (27–35 °C) on rennet coagulation of goat milk. Coagulation time (RCT), aggregation rate (AR), and gel firmness (G’60 and GF), were measured by oscillatory rheometry. The decrease in rennet concentration extended RCT. At lower rennet concentrations, a lower AR was recorded, which ranged from 0.02 Pa/s to 0.05 Pa/s. The decrease in pH from 6.5 to 6.1 caused a two times shorter RCT, and a two times faster AR. There was no effect of pH on the firmness of the rennet gel. The increase in coagulation temperature from 27 °C to 35 °C reduced the RCT of pasteurized milk from 12.6 min to 8.6 min, and caused a linear increase in the AR, but did not significantly affect the firmness of the gel. The present study revealed that the optimization of the rennet coagulation process could be directed towards pH lowering, or temperature increase, since they accelerate the process, but do not alter the examined gel firmness parameters. Full article
(This article belongs to the Special Issue Trends in the Development and Use of Fermented Dairy Products)
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15 pages, 3783 KiB  
Article
Textural and Functional Properties of Skimmed and Whole Milk Fermented by Novel Lactiplantibacillus plantarum AG10 Strain Isolated from Silage
by Elena Nikitina, Tatyana Petrova, Adel Vafina, Asya Ezhkova, Monyr Nait Yahia and Airat Kayumov
Fermentation 2022, 8(6), 290; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060290 - 20 Jun 2022
Cited by 6 | Viewed by 2155
Abstract
Milk fermentation by lactic acid bacteria both enhances its nutritional value and provides probiotic strains to correct the intestinal microflora. Here, we show the comparative analysis of milk fermented with the new strain, Lactiplantibacillus plantarum AG10, isolated from silage and the industrial strain [...] Read more.
Milk fermentation by lactic acid bacteria both enhances its nutritional value and provides probiotic strains to correct the intestinal microflora. Here, we show the comparative analysis of milk fermented with the new strain, Lactiplantibacillus plantarum AG10, isolated from silage and the industrial strain Lactobacillus delbrukii subs. bulgaricus. While the milk acidification during fermentation with L. plantarum AG10 was lower compared with L. bulgaricus, milk fermented with L. plantarum AG10 after a 14-day storage period retained a high level of viable cells and was characterized by an increased content of exopolysaccharides and higher viscosity. The increased EPS production led to clot formation with higher density on microphotographs and increased firmness and cohesiveness of the product compared with L. bulgaricus-fermented milk. Furthermore, the L. plantarum AG10-fermented milk exhibited increased radical-scavenging activity assuming lower fat oxidation during storage. Taken together, these data suggest that L. plantarum AG10 seems to be a promising starter culture for dairy products with lowered levels of lactic acid, which is important for people with increased gastric acid formation. Full article
(This article belongs to the Special Issue The Role of Antioxidant Compounds in Fermented Foods)
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11 pages, 2041 KiB  
Article
Improved Hydrogen Peroxide Stress Resistance of Zymomonas mobilis NADH Dehydrogenase (ndh) and Alcohol Dehydrogenase (adhB) Mutants
by Kristiana Kovtuna, Inese Strazdina, Mara Bikerniece, Nina Galinina, Reinis Rutkis, Jekaterina Martynova and Uldis Kalnenieks
Fermentation 2022, 8(6), 289; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060289 - 19 Jun 2022
Viewed by 1642
Abstract
Unintended shifts in stress resistance of microbial strains with engineered central metabolism may impact their growth and production performance under oxidative, lignocellulosic, solvent, and other stress conditions, and as such, must be taken into account in bioprocess design. In the present work, we [...] Read more.
Unintended shifts in stress resistance of microbial strains with engineered central metabolism may impact their growth and production performance under oxidative, lignocellulosic, solvent, and other stress conditions, and as such, must be taken into account in bioprocess design. In the present work, we studied oxidative stress resistance in mutant strains of the facultatively anaerobic, ethanologenic bacterium Zymomonas mobilis with modified respiratory (inactivated NADH dehydrogenase Ndh, by disruption of ndh) and ethanologenic (inactivated iron-containing alcohol dehydrogenase isoenzyme ADH II, by disruption of adhB) catabolism, using exogenously added H2O2 in the concentration range of 2–6 mM as the oxidative stressor. Both mutations improved H2O2 resistance and enhanced catalase activity by a factor of 2–5, while the overexpression of Ndh had an opposite effect. Strains with a catalase-negative background were unable to grow already at 1 mM hydrogen peroxide, and their H2O2 resistance did not depend on AdhB or Ndh expression levels. Hence, the improved resistance of the ndh and adhB mutants to H2O2 resulted from their elevated catalase activity. The interrelation between these mutations, the catabolic redox balance, catalase activity, and oxidative stress defense in Z. mobilis is discussed. Full article
(This article belongs to the Special Issue Bioconversion of Lignocellulosic Materials to Value-Added Products)
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10 pages, 264 KiB  
Article
Effects of Rubber Seed Kernel Fermented with Yeast on Feed Utilization, Rumen Fermentation and Microbial Protein Synthesis in Dairy Heifers
by Nirawan Gunun, Thanaporn Ouppamong, Pichad Khejornsart, Anusorn Cherdthong, Metha Wanapat, Sineenart Polyorach, Chatchai Kaewpila, Sungchhang Kang and Pongsatorn Gunun
Fermentation 2022, 8(6), 288; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060288 - 19 Jun 2022
Cited by 14 | Viewed by 2588
Abstract
Yeast (Saccharomyces cerevisiae) has been used to improve the nutritive value of feedstuffs, especially rubber seed kernel. In the current study, rubber seed kernel was grated and subjected to solid-state fermentation with yeast to enhance the nutritive value. The yeast-fermented rubber [...] Read more.
Yeast (Saccharomyces cerevisiae) has been used to improve the nutritive value of feedstuffs, especially rubber seed kernel. In the current study, rubber seed kernel was grated and subjected to solid-state fermentation with yeast to enhance the nutritive value. The yeast-fermented rubber seed kernel (YERSEK) was substituted for soybean meal in ruminant diets to evaluate the effect of YERSEK on feed intake, digestibility, rumen fermentation and microbial protein synthesis in dairy heifers. Five Holstein Friesian crossbred heifers with an initial body weight (BW) of 215 ± 20 kg were used in this research. The experimental design was a 5 × 5 Latin squared design and the dietary treatments were five levels of YERSEK at 0, 100, 150, 200 and 250 g/kg dry matter in concentrate at 1% of BW, with rice straw fed ad libitum. The supplementation with YERSEK reduced rice straw and total DM intake linearly (p < 0.05). The intake of neutral detergent fiber and acid detergent fiber decreased linearly (p < 0.05), while ether extract intake increased linearly (p < 0.01) with YERSEK supplementation. The ether extract digestibility tended to be high (p < 0.01) with increasing levels of YERSEK. Supplementation with the YERSEK did not change (p > 0.05) ruminal pH and blood urea nitrogen in this study, but ruminal ammonia nitrogen was increased (p < 0.01) in the heifers receiving YERSEK. Increasing the YERSEK levels did not adversely affect the proportion of volatile fatty acids (VFA), which included acetate, propionate and butyrate and the microbial population (p > 0.05). Microbial protein synthesis was similar among the treatments (p > 0.05). The inclusion of YERSEK at 250 g/kg DM in concentrate feed had no effect on the utilization of feed, rumen fermentation characteristics and microbial protein synthesis. The YERSEK could be used as a protein replacement for up to 86% of the soybean meal in feed concentrate for dairy heifers. Full article
(This article belongs to the Special Issue Recent Advances in Rumen Fermentation Efficiency)
11 pages, 1513 KiB  
Communication
Scanning Electron Microscopy Study on the Biodeterioration of Natural Fiber Materials Compared to Disposable Hygiene and Sanitary Products
by Laura-Dorina Dinu, Ovidiu Iordache and Emanuel Vamanu
Fermentation 2022, 8(6), 287; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060287 - 17 Jun 2022
Cited by 2 | Viewed by 2462
Abstract
Disposable personal care products are part of modern life, but these products could become a biological hazard in case of improper disposal. Therefore, our study compared the biodeterioration of plant-based woven materials (cotton, linen), animal materials (wool, leather), disposable hygiene products with cellulose [...] Read more.
Disposable personal care products are part of modern life, but these products could become a biological hazard in case of improper disposal. Therefore, our study compared the biodeterioration of plant-based woven materials (cotton, linen), animal materials (wool, leather), disposable hygiene products with cellulose fibers (sanitary pads, cosmetic pads), and chemical impregnated products (antimicrobial/sanitary wet wipes) using burial tests in two types of soils for 40 days. Weight loss (%) and scanning electron microscopy (SEM) revealed that textiles are relatively quickly deteriorated compared to animal-based products, and the process is dependent on the soil type. According to SEM analysis, sanitary pads were the least deteriorated, followed by wet wipes and cosmetic pads (maximum weight loss 24.332% and 27.537%, respectively), and the process was influenced by the composition and structure of the product. These results were correlated with changes in the number of microbes and cellulolytic activity of soil near the samples, and eight isolates belong to Ascomycetes according to PCR analysis. This is the first report on the fate of disposable hygiene and sanitary products in soil, but further comprehensive research is required to reveal crucial insights about their potential hazards and to increase public awareness of the inappropriate disposal of these products. Full article
(This article belongs to the Special Issue Biotransformation of Plant Materials by Molds and Higher Fungi)
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26 pages, 2698 KiB  
Article
Multiparametric Approach to Interactions between Saccharomyces cerevisiae and Lachancea thermotolerans during Fermentation
by Alexis Joran, Géraldine Klein, Chloé Roullier-Gall and Hervé Alexandre
Fermentation 2022, 8(6), 286; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060286 - 17 Jun 2022
Cited by 1 | Viewed by 1926
Abstract
The aim of a significant part of current wine technology research is to better understand and monitor mixed culture fermentations and optimize the microbiological processes and characteristics of the final wine. In this context, the yeast couple formed by Lachancea thermotolerans and Saccharomyces [...] Read more.
The aim of a significant part of current wine technology research is to better understand and monitor mixed culture fermentations and optimize the microbiological processes and characteristics of the final wine. In this context, the yeast couple formed by Lachancea thermotolerans and Saccharomyces cerevisiae is of particular interest. The diverse results observed in the literature have shown that wine characteristics are dependent on both interactions between yeasts and environmental and fermentation parameters. Here, we took a multiparametric approach to study the impact of fermentation parameters on three different but related aspects of wine fermentation: population dynamics, fermentation, and volatile compound production. An experimental design was used to assess the effects of four independent factors (temperature, oxygenation, nitrogen content, inoculum ratio) on variables representing these three aspects. Temperature and, to a lesser extent, oxygenation and the inoculum ratio, were shown to constitute key factors in optimizing the presence of Lachancea thermotolerans during fermentation. The inoculum ratio also appeared to greatly impact lactic acid production, while the quantity of nitrogen seemed to be involved more in the management of aroma compound production. These results showed that a global approach to mixed fermentations is not only pertinent, but also constitutes an important tool for controlling them. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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20 pages, 1847 KiB  
Article
The Effect of Different Lactic Acid Bacteria Inoculants on Silage Quality, Phenolic Acid Profiles, Bacterial Community and In Vitro Rumen Fermentation Characteristic of Whole Corn Silage
by Yan-Lu Wang, Wei-Kang Wang, Qi-Chao Wu, Fan Zhang, Wen-Juan Li, Zhuo-Meng Yang, Yu-Kun Bo and Hong-Jian Yang
Fermentation 2022, 8(6), 285; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060285 - 17 Jun 2022
Cited by 13 | Viewed by 2602
Abstract
Corn silage is an important source of forage, but whether or not bacterial inoculants should be applied is somewhat controversial in ruminant feeding practice. In the present study, chopped whole corn plants treated with a single inoculant of Lactobacillus buchneri (LB), Lactobacillus plantarum [...] Read more.
Corn silage is an important source of forage, but whether or not bacterial inoculants should be applied is somewhat controversial in ruminant feeding practice. In the present study, chopped whole corn plants treated with a single inoculant of Lactobacillus buchneri (LB), Lactobacillus plantarum (LP), Pediococcus pentosaceus (PP) served as either homofermentation (e.g., lactate only) or heterofermentation (e.g., lactate and acetate) controls and compared with those treated with either a mixture of the lactic acid bacteria (QA: 60% LP, 10%PP, 30% LB) or a mixture of the lactic acid bacteria (QB: 60% LP, 15% PP, 25% LB), to investigate their effects on the fermentation quality, ester-linked phenolic acids, and in vitro digestibility. After 60 day ensiling, the addition of QA exhibited the lowest pH (3.51) with greater lactic acid (LA) production. The ester-linked ferulic acid (FAest) and p-coumaric acid (pCAest) concentrations were significantly decreased during 60 days ensiling. And among all these groups, the LB and QA treated group showed a lower concentration of FAest and pCAest than other groups. After 60 days ensiling, Lactobacillus was the dominant genus in all LAB treated groups. Meanwhile, negative correlations of Bacillus, Bacteroides, Bifidobacterium, Blautia, Prevotella, Ruminococcus, and Roseburia with FAest content after 60 days ensiling occurred in the present study. Komagataeibacter was mainly found in LB and PP addition silages, and presented a significant negative effect with the level of acid detergent fiber (ADF). To explore whether the addition of LABs can improve digestibility of whole corn silage, an in vitro rumen fermentation was conducted using the 60 day ensiled whole corn silages as substrates. The QA addition group exhibited a greater 48 h and 96 h in vitro dry matter and ADF disappearance, greater 48 h gas production and less methane emissions. Even though there were the same neutral NDF levels in corn silages treated with LB and QA after 60 days ensiling, the QA treated silages with lower FAest and pCAest presented higher IVDMD after 96 h and 48 h in vitro fermentation. In brief, the addition of mixed inoculants of 60% LB,10% PP, 30% LB compared with the addition of whichever single HoLAB or HeLAB inoculants, facilitated the release of ester-linked phenolic acids (e.g., ferulic and p-coumaric acids) and remarkably, improved silage quality in terms of sharp pH decline and greater lactate production. Taken together with the improvement in rumen microbial fermentation, the results obtained in the present study provided concrete evidence for the role of mixed LAB application in corn silage preparation for ruminant feeding practices. Full article
(This article belongs to the Special Issue In Vitro Fermentation)
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11 pages, 1377 KiB  
Article
Valorization of Low-Cost Substrates for the Production of Odd Chain Fatty Acids by the Oleaginous Yeast Yarrowia lipolytica
by Sally El Kantar and Mohamed Koubaa
Fermentation 2022, 8(6), 284; https://doi.org/10.3390/fermentation8060284 - 16 Jun 2022
Cited by 7 | Viewed by 1960
Abstract
Odd-chain fatty acids (OCFAs) have recently gained interest as target compounds in microbial production due to their diverse applications in the medical, pharmaceutical and chemical industries for the production of biofuels. Yarrowia lipolytica is a promising oleaginous yeast that has the ability to [...] Read more.
Odd-chain fatty acids (OCFAs) have recently gained interest as target compounds in microbial production due to their diverse applications in the medical, pharmaceutical and chemical industries for the production of biofuels. Yarrowia lipolytica is a promising oleaginous yeast that has the ability to accumulate high quantities of fatty acids. However, the use of Y. lipolytica oils is still under research, in order to decrease the production costs related to the fermentation process and improve economic feasibility. In this work, sugar beet molasses (10–50 g/L) and crude glycerol (30 g/L) were used as the main carbon sources to reduce the processing costs of oil production from a genetically engineered Y. lipolytica strain. The effects of medium composition were studied on biomass production, lipid content, and OCFAs profile. Lipid production by yeast growing on molasses (20 g/L sucrose) and crude glycerol reached 4.63 ± 0.95 g/L of culture medium. OCFAs content represented 58% of the total fatty acids in lipids, which corresponds to ≈2.69 ± 0.03 g/L of culture medium. The fermentation was upscaled to 5 L bioreactors and fed-batch co-feeding increased OCFA accumulation in Y. lipolytica by 56% compared to batch cultures. Full article
(This article belongs to the Special Issue Waste Fermentation and Volatile Fatty Acids)
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11 pages, 2835 KiB  
Article
Isolation of Novel Yeast from Coconut (Cocos nucifera L.) Water and Phenotypic Examination as the Potential Parameters in Bioethanol Production
by Getari Kasmiarti, Dwita Oktiarni, Poedji Loekitowati Hariani, Novia Novia and Hermansyah Hermansyah
Fermentation 2022, 8(6), 283; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060283 - 16 Jun 2022
Viewed by 2460
Abstract
Yeast is a fermentation agent for producing bioethanol as an environmentally friendly alternative energy. Therefore, this study aims to find novel yeasts with the capability to persevere under acidic, high temperature, and high sugar content conditions, which are required in the bioethanol industry. [...] Read more.
Yeast is a fermentation agent for producing bioethanol as an environmentally friendly alternative energy. Therefore, this study aims to find novel yeasts with the capability to persevere under acidic, high temperature, and high sugar content conditions, which are required in the bioethanol industry. The yeasts were isolated and identified from coconut (Cocos nucifera L.) water by a DNA sequencing method and phenotypic test. Yeast isolation has been completed with a serial dilution procedure and purification was conducted with HiPurA Genomic DNA Purification Spin Kits, which were analyzed by DNA Sequencing. The phenotypic test was carried out with thermotolerant (30 °C and 41 °C), high acidity (lactic acid), and sugar content (molasses 35 °brix) parameters in the media as the initial step of yeast ability screening. Based on the results, the three species of Candida tropicalis K5 (Candida tropicalis strain L2), K15 (Candida tropicalis strain MYA-3404), and K20 (Candida tropicalis strain Y277) obtained met the phenotypic standards. This showed that the yeasts have the potential to produce molasses-based bioethanol. Full article
(This article belongs to the Special Issue Yeast, Biofuels, and Value-Added Products)
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10 pages, 1956 KiB  
Article
Increasing Anaerobic Digestion Efficiency Using Food-Waste-Based Biochar
by Dong-Chul Shin, I-Tae Kim, Jinhong Jung, Yoonah Jeong, Ye-Eun Lee and Kwang-Ho Ahn
Fermentation 2022, 8(6), 282; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060282 - 16 Jun 2022
Cited by 10 | Viewed by 2936
Abstract
The efficiency of methane production by anaerobic digestion (AD), during which energy is generated from organic waste, can be increased in various ways. Recent research developments have increased the volume of gas production during AD using biochar. Previous studies have used food waste [...] Read more.
The efficiency of methane production by anaerobic digestion (AD), during which energy is generated from organic waste, can be increased in various ways. Recent research developments have increased the volume of gas production during AD using biochar. Previous studies have used food waste itself in AD, or, added wood-biochar or sewage sludge charcoal as an accelerant of the AD process. The application of food-waste biochar in AD using activated sludge has not yet been studied and is considered a potential method of utilizing food waste. Therefore, this study investigated the use of biochar prepared by the thermal decomposition of food waste as an additive to AD tanks to increase methane production. The addition of food-waste biochar at 1% of the digestion tank volume increased the production of digestion gas by approximately 10% and methane by 4%. We found that food-waste biochar served as a medium with trace elements that promoted the proliferation of microorganisms and increased the efficiency of AD. Full article
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19 pages, 3159 KiB  
Article
Changes and Driving Mechanism of Microbial Community Structure during Paocai Fermentation
by Pingmei Yan, Jingjing Jia, Huwei Zhao and Chendong Wu
Fermentation 2022, 8(6), 281; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060281 - 16 Jun 2022
Cited by 3 | Viewed by 1937
Abstract
Fermentation of paocai is a dynamic process of the microbial community structure, and the interaction between community structure and physicochemical factors endows paocai with unique taste and flavor. The study of bacterial and fungal community structure changes and the driving mechanism of physicochemical [...] Read more.
Fermentation of paocai is a dynamic process of the microbial community structure, and the interaction between community structure and physicochemical factors endows paocai with unique taste and flavor. The study of bacterial and fungal community structure changes and the driving mechanism of physicochemical factors induced changes in community structure, showing that Pseudomonas belonging to Proteobacteria and Lactobacillus belonging to Firmicutes were the dominant bacteria in the process of paocai fermentation. The correlation analysis of physicochemical factors with bacterial community showed that titratable acid was significantly positively correlated with Lactobacillus and negatively correlated with Pseudomonas, while nitrite was the opposite. Redundancy analysis (RDA) showed that pH was positively correlated with the bacterial community in the early fermentation stage, amino acid nitrogen was positively correlated with the bacterial community in the middle fermentation stage, and titratable acid was positively correlated with the bacterial community in the late fermentation stage. Variance partitioning analysis (VPA) showed that environmental factors, pH and metabolites, were the main driving forces of bacterial community diversity, which jointly explained 32.02% of the bacterial community structure variation. To study the glucolysis and nitrogen metabolism in the process of paocai fermentation, we found that in the early stage of the fermentation, the nitrite reductase enzyme of Pseudomonas activity was high, with high nitrite content in the prophase, but by the end of fermentation, lactic acid bacteria rapidly increased, the content of L−lactic acid through the glycolysis pathway, making paocai fermentation environment become acidic, then Pseudomonas decreased. Ascomycota and Basidiomycota were the main phylum fungi in the fermentation process. RDA analysis showed that the fungal community was positively correlated with pH, nitrite, and soluble protein at the early fermentation stage, amino acid nitrogen was positively correlated with the fungal community at the middle fermentation stage, titratable acid and reducing sugar were positively correlated with the fungal community at the late fermentation stage. VPA analysis showed that metabolites were the main driving force of fungal community diversity and accounted for 45.58% of fungal community diversity. These results had a certain guiding significance for the production and preservation of naturally fermented paocai. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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22 pages, 2864 KiB  
Article
New Approaches for the Fermentation of Beer: Non-Saccharomyces Yeasts from Wine
by Vanesa Postigo, Ana Sánchez, Juan Mariano Cabellos and Teresa Arroyo
Fermentation 2022, 8(6), 280; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060280 - 15 Jun 2022
Cited by 11 | Viewed by 3830
Abstract
Non-Saccharomyces yeasts represent a very attractive alternative for the production of beers with superior sensory quality since they are able to enhance the flavour of beer. Furthermore, they can produce beers with low ethanol content due to the weak fermentative capacity of [...] Read more.
Non-Saccharomyces yeasts represent a very attractive alternative for the production of beers with superior sensory quality since they are able to enhance the flavour of beer. Furthermore, they can produce beers with low ethanol content due to the weak fermentative capacity of a large percentage of non-Saccharomyces species. The objective of this study was to evaluate the ability of 34 non-Saccharomyces yeast strains isolated from Madrilenian agriculture to produce a novel ale beer. The non-Saccharomyces yeast strains were screened at two scales in the laboratory. In the first screening, those with undesirable aromas were discarded and the selected strains were analysed. Thirty-three volatile compounds were analysed by GC, as well as melatonin production by HPLC, for the selected strains. Thirteen strains were then fermented at a higher scale in the laboratory for sensory evaluation. Only yeast strains of the species Schizosaccharomyces pombe and Lachancea thermotolerans were able to complete fermentation. Species such as Torulaspora delbrueckii, Metschnikowia pulcherrima, Wickerhamomyces anomalus, Hanseniaspora vineae, and Hanseniaspora guilliermondii could be used both for production of low ethanol beers and co-fermentation with a Saccharomyces yeast to improve the organoleptic characteristics of the beer. In addition, for these strains, the levels of melatonin obtained were higher than the concentrations found for Saccharomyces strains subjected to the same study conditions. The selected strains can be used in future trials to further determine their viability under different conditions and for different purposes. Full article
(This article belongs to the Special Issue Enological Repercussions of Non-saccharomyces Species 4.0)
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17 pages, 2251 KiB  
Review
Engineered Microbial Cell Factories for Sustainable Production of L-Lactic Acid: A Critical Review
by Tiantian Liu, Xianhao Xu, Yanfeng Liu, Jianghua Li, Guocheng Du, Xueqin Lv and Long Liu
Fermentation 2022, 8(6), 279; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060279 - 15 Jun 2022
Cited by 9 | Viewed by 2853
Abstract
With the increasing demand for the biodegradable polymer material polylactic acid and its advantage of being metabolized by the human body, L-lactic acid (L-LA) is becoming increasingly attractive in environmental protection and food industry applications. However, the supply of L-LA is not satisfied, [...] Read more.
With the increasing demand for the biodegradable polymer material polylactic acid and its advantage of being metabolized by the human body, L-lactic acid (L-LA) is becoming increasingly attractive in environmental protection and food industry applications. However, the supply of L-LA is not satisfied, and the price is still high. Compared to enzymatic and chemical synthesis methods, L-LA production by microbial fermentation has the advantages of low cost, large yield, simple operation, and environmental protection. This review summarizes the advances in engineering microbial cell factories to produce L-LA. First, the synthetic pathways and microorganisms for L-LA production are outlined. Then, the metabolic engineering strategies for constructing cell factories to overproduce L-LA are summarized and fermentation modes for L-LA production are also given. Finally, the challenges and prospects of the microbial production of L-LA are discussed. This review provides theoretical guidance for researchers engaged in L-LA production. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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17 pages, 707 KiB  
Article
Rhizopus oryzae for Fumaric Acid Production: Optimising the Use of a Synthetic Lignocellulosic Hydrolysate
by Reuben Marc Swart, Hendrik Brink and Willie Nicol
Fermentation 2022, 8(6), 278; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060278 - 15 Jun 2022
Cited by 3 | Viewed by 2238
Abstract
The hydrolysis of lignocellulosic biomass opens an array of bioconversion possibilities for producing fuels and chemicals. Microbial fermentation is particularly suited to the conversion of sugar-rich hydrolysates into biochemicals. Rhizopus oryzae ATCC 20344 was employed to produce fumaric acid from glucose, xylose, and [...] Read more.
The hydrolysis of lignocellulosic biomass opens an array of bioconversion possibilities for producing fuels and chemicals. Microbial fermentation is particularly suited to the conversion of sugar-rich hydrolysates into biochemicals. Rhizopus oryzae ATCC 20344 was employed to produce fumaric acid from glucose, xylose, and a synthetic lignocellulosic hydrolysate (glucose–xylose mixture) in batch and continuous fermentations. A novel immobilised biomass reactor was used to investigate the co-fermentation of xylose and glucose. Ideal medium conditions and a substrate feed strategy were then employed to optimise the production of fumaric acid. The batch fermentation of the synthetic hydrolysate at optimal conditions (urea feed rate 0.625mgL−1h−1 and pH 4) produced a fumaric acid yield of 0.439gg−1. A specific substrate feed rate (0.164gL−1h−1) that negated ethanol production and selected for fumaric acid was determined. Using this feed rate in a continuous fermentation, a fumaric acid yield of 0.735gg−1 was achieved; this was a 67.4% improvement. A metabolic analysis helped to determine a continuous synthetic lignocellulosic hydrolysate feed rate that selected for fumaric acid production while achieving the co-fermentation of glucose and xylose, thus avoiding the undesirable carbon catabolite repression. This work demonstrates the viability of fumaric acid production from lignocellulosic hydrolysate; the process developments discovered will pave the way for an industrially viable process. Full article
(This article belongs to the Special Issue Carboxylic Acid Production 2.0)
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18 pages, 1334 KiB  
Article
Probiotic and Antifungal Attributes of Lactic Acid Bacteria Isolates from Naturally Fermented Brazilian Table Olives
by Luara Simões, Natália Fernandes, Angélica de Souza, Luiz dos Santos, Marciane Magnani, Luís Abrunhosa, José Teixeira, Rosane Freitas Schwan and Disney Ribeiro Dias
Fermentation 2022, 8(6), 277; https://doi.org/10.3390/fermentation8060277 - 14 Jun 2022
Cited by 5 | Viewed by 2253
Abstract
Research with fermented olives as a source of wild Lactic Acid Bacteria (LAB) strains with probiotic and biotechnological characteristics constitutes a promising field of work. The present study evaluated in vitro probiotic, antifungal, and antimycotoxigenic potential of LAB isolates from naturally fermented Brazilian [...] Read more.
Research with fermented olives as a source of wild Lactic Acid Bacteria (LAB) strains with probiotic and biotechnological characteristics constitutes a promising field of work. The present study evaluated in vitro probiotic, antifungal, and antimycotoxigenic potential of LAB isolates from naturally fermented Brazilian table olives. Among fourteen LAB isolates, the Levilactobacillus brevis CCMA 1762, Lactiplantibacillus pentosus CCMA 1768, and Lacticaseibacillus paracasei subsp. paracasei CCMA 1770 showed potential probiotic and antifungal properties. The isolates showed resistance to pH 2.0 (survival ≥ 84.55), bile salts (survival ≥ 99.44), and gastrointestinal tract conditions (survival ≥ 57.84%); hydrophobic cell surface (≥27%); auto-aggregation (≥81.38%); coaggregation with Escherichia coli INCQS 00181 (≥33.97%) and Salmonella Enteritidis ATCC 564 (≥53.84%); adhesion to the epithelial cell line Caco-2 (≥5.04%); antimicrobial activity against the bacteria S. Enteritidis ATCC 564 (≥6 mm), Listeria monocytogenes ATCC 19117 (≥6 mm), Staphylococcus aureus ATCC 8702 (≥3 mm), and the fungi Penicillium nordicum MUM 08.16 (inhibition ≥ 64.8%). In addition, the strains showed the ability to adsorb the mycotoxins aflatoxin B1 (≥40%) and ochratoxin A (≥34%). These results indicate that LAB strains from naturally fermented Brazilian table olives are potentially probiotic and antifungal candidates that can be used for food biopreservation. Full article
(This article belongs to the Special Issue Food Fermentation for Better Nutrition, Health and Sustainability)
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15 pages, 1019 KiB  
Article
Dynamic Variations in Rumen Fermentation Characteristics and Bacterial Community Composition during In Vitro Fermentation
by Xiao Wei, Kehui Ouyang, Tanghui Long, Zuogui Liu, Yanjiao Li and Qinghua Qiu
Fermentation 2022, 8(6), 276; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060276 - 14 Jun 2022
Cited by 11 | Viewed by 2849
Abstract
This study aimed to explore the dynamic variations of rumen fermentation characteristics and bacterial community composition during a 24 h in vitro fermentation. A total of twenty-three samples were collected from original rumen fluid (ORF, n = 3), fermentation at 12 h (R12, [...] Read more.
This study aimed to explore the dynamic variations of rumen fermentation characteristics and bacterial community composition during a 24 h in vitro fermentation. A total of twenty-three samples were collected from original rumen fluid (ORF, n = 3), fermentation at 12 h (R12, n = 10), and fermentation at 24 h (R24, n = 10). Results showed that gas production, concentrations of microbial crude protein, ammonia nitrogen, and individual volatile fatty acids (VFA), as well as total VFA and branched-chain VFA concentrations, were higher in R24 when compared with R12 (p < 0.05). However, no significant differences were observed in acetate to propionate ratio and fermentation efficiency between R12 and R24 (p > 0.05). Bacterial diversity analysis found that Shannon index and Simpson index were higher in R24 (p < 0.05), and obvious clusters were observed in rumen bacterial community between R12 and R24. Taxonomic analysis at the phylum level showed that the abundances of Proteobacteria and Fibrobacteres were higher in R12 than that in R24, and inverse results were observed in Bacteroidetes, Firmicutes, Cyanobacteria, Verrucomicrobia, Lentisphaerae, and Synergistetes abundances. Taxonomic analysis at the genus level revealed that the abundances of Rikenellaceae RC9 gut group, Succiniclasticum, Prevotellaceae UCG-003, Christensenellaceae R-7 group, Ruminococcaceae UCG-002, Veillonellaceae UCG-001, and Ruminococcaceae NK4A214 group were higher in R24, whereas higher abundances of Succinivibrionaceae UCG-002, Ruminobacter, and Fibrobacter, were found in R12. Correlation analysis revealed the negative associations between gas production and abundances of Proteobacteria, Succinivibrionaceae UCG-002, and Ruminobacter. Moreover, the abundances of Firmicutes, Rikenellaceae RC9 gut group, Christensenellaceae R-7 group, and Ruminococcaceae UCG-002 positively correlated with VFA production. These results indicate that both rumen fermentation characteristics and bacterial community composition were dynamic during in vitro fermentation, whereas the fermentation pattern, efficiency, and bacterial richness remained similar. This study provide insight into the dynamics of rumen fermentation characteristics and bacterial composition during in vitro fermentation. This study may also provide a reference for decision-making for the sampling time point when conducting an in vitro fermentation for bacterial community investigation. Full article
(This article belongs to the Special Issue In Vitro Fermentation)
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15 pages, 968 KiB  
Review
Microbial Resources and Sparkling Wine Differentiation: State of the Arts
by Vittorio Capozzi, Maria Tufariello, Carmen Berbegal, Mariagiovanna Fragasso, Nicola De Simone, Giuseppe Spano, Pasquale Russo, Pasquale Venerito, Francesco Bozzo and Francesco Grieco
Fermentation 2022, 8(6), 275; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060275 - 14 Jun 2022
Cited by 3 | Viewed by 2763
Abstract
Consumers’ increasing interest in sparkling wine has enhanced the global market’s demand. The pro-technological yeasts strains selected for the formulation of microbial starter cultures are a fundamental parameter for exalting the quality and safety of the final product. Nowadays, the management of the [...] Read more.
Consumers’ increasing interest in sparkling wine has enhanced the global market’s demand. The pro-technological yeasts strains selected for the formulation of microbial starter cultures are a fundamental parameter for exalting the quality and safety of the final product. Nowadays, the management of the employed microbial resource is highly requested by stakeholders, because of the increasing economic importance of this oenological sector. Here, we report an overview of the production processes of sparkling wine and the main characterisation criteria to select Saccharomyces and non-Saccharomyces strains appropriate for the preparation of commercial starter cultures dedicated to the primary and, in particular, the secondary fermentation of sparkling wines. We also focused on the possible uses of selected indigenous strains to improve the unique traits of sparkling wines from particular productive areas. In summary, the sparkling wine industry will get an important advantage from the management of autochthonous microbial resources associated with vineyard/wine microbial diversity. Full article
(This article belongs to the Special Issue New Insight and Current Trends in Oenological Microbiology)
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11 pages, 941 KiB  
Article
Effectiveness of Tannin Removal by Alkaline Pretreatment on Sorghum Ethanol Production
by Franco Foglia, Caye Drapcho and John Nghiem
Fermentation 2022, 8(6), 274; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060274 - 13 Jun 2022
Cited by 1 | Viewed by 1644
Abstract
Sorghum has been proposed as a complement or replacement for corn in ethanol production. One difference between sorghum and corn is the presence of tannins, which may affect enzymatic activity. High-tannin sorghum hybrid XM217 was used to analyze the effect of tannin removal [...] Read more.
Sorghum has been proposed as a complement or replacement for corn in ethanol production. One difference between sorghum and corn is the presence of tannins, which may affect enzymatic activity. High-tannin sorghum hybrid XM217 was used to analyze the effect of tannin removal by the alkaline pretreatment of sorghum for ethanol production. A laboratory-scale dry-milling process was used on treated sorghum/corn blends to generate mash that was fermented by Saccharomyces cerevisiae and then compared to a 100% untreated sorghum control. Cellulase was added to a similar set of mash to determine the feasibility of the tannin-removal treatment as a pretreatment method for cellulosic ethanol production. Theoretical ethanol yield increased from 68.2 ± 1.5% to 78.5 ± 2.5% for alkaline-pretreated sorghum vs. untreated sorghum, with a corresponding increase in mean ethanol concentrations from 8.02 ± 0.15 to 9.39 ± 0.26% w/v. The average theoretical ethanol yield increased from 69.8 ± 1.7% to 94.6 ± 1.9% when using cellulase with untreated and treated sorghum. The use of alkaline tannin removal resulted in a significant increase in the theoretical ethanol yield obtained when using 100% sorghum, when compared to the theoretical ethanol yield obtained when using 100% corn. The combination of cellulase and alkaline tannin removal improved the yield of ethanol in all cases compared to the experiments without cellulase. Full article
(This article belongs to the Special Issue Ethanol and Value-Added Co-products 3.0)
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32 pages, 534 KiB  
Review
Maltose-Negative Yeast in Non-Alcoholic and Low-Alcoholic Beer Production
by Selin Yabaci Karaoglan, Rudolf Jung, Matthew Gauthier, Tomáš Kinčl and Pavel Dostálek
Fermentation 2022, 8(6), 273; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060273 - 12 Jun 2022
Cited by 12 | Viewed by 6648
Abstract
Although beer is a widely used beverage in many cultures, there is a need for a new drinking alternative in the face of rising issues such as health concerns or weight problems. However, non-alcoholic and low-alcoholic beers (NABLAB) still have some sensory problems [...] Read more.
Although beer is a widely used beverage in many cultures, there is a need for a new drinking alternative in the face of rising issues such as health concerns or weight problems. However, non-alcoholic and low-alcoholic beers (NABLAB) still have some sensory problems that have not been fully remedied today, such as “wort-like”/”potato-like” flavours or a lack of aroma. These defects are due to the lack of alcohol (and the lack of the aldehyde-reducing effect of alcohol fermentation), as well as production techniques. The use of new yeast strains that cannot ferment maltose—the foremost sugar in the wort—is highly promising to produce a more palatable and sustainable NABLAB product because production with these yeast strains can be performed with standard brewery equipment. In the scientific literature, it is clear that interest in the production of NABLAB has increased recently, and experiments have been carried out with maltose-negative yeast strains isolated from many different environments. This study describes maltose-negative yeasts and their aromatic potential for the production of NABLAB by comprehensively examining recent academic studies. Full article
13 pages, 2575 KiB  
Article
Spray-Dried Nipa Palm Vinegar Powder: Production and Evaluation of Physicochemical, Nutritional, Sensory, and Storage Aspects
by Wilawan Palachum, Wiyada Kwanhian Klangbud and Yusuf Chisti
Fermentation 2022, 8(6), 272; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060272 - 11 Jun 2022
Cited by 3 | Viewed by 6097
Abstract
Nipa palm vinegar (NPV) is a naturally fermented vinegar derived from the nipa palm (Nypa fruticans Wurmb) sap. This work optimized production of spray-dried nipa palm vinegar powder. The influence of the various drier air inlet temperatures (150, 170, and 190 °C) [...] Read more.
Nipa palm vinegar (NPV) is a naturally fermented vinegar derived from the nipa palm (Nypa fruticans Wurmb) sap. This work optimized production of spray-dried nipa palm vinegar powder. The influence of the various drier air inlet temperatures (150, 170, and 190 °C) and maltodextrin DE10 carrier concentrations (15 and 20% w/v) in the feed, on the characteristics of the product powder was investigated. Nipa palm vinegar powder (NPVp) was evaluated in terms of the following responses: physicochemical and nutritional properties, sensory acceptability, and storage stability. All processing variables affected the responses. Based on product desirability as the optimization criterion, spray-drying with a hot air inlet temperature of 170 °C with a 15% w/v maltodextrin DE10 in the feed was optimal. The nutritional characteristics of the product made under the above identified optimal conditions were (per 100 g dry product): a calorific value of 366.2 kcal; 1.3 g protein; 88.1 g carbohydrate; 0.96 g fat; 883.9 mg potassium; 12.7 mg vitamin C; and 105 mg gallic acid equivalent (GAE) phenolics content. The product, vacuum-packed and heat-sealed in aluminum laminated polyethylene bags, could be stored at 25 °C for at least 180 days without noticeable loss in quality. Full article
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10 pages, 2042 KiB  
Article
Improved Production of α-Amylase by Aspergillus terreus in Presence of Oxygen-Vector
by Alexandra Cristina Blaga, Dan Caşcaval and Anca Irina Galaction
Fermentation 2022, 8(6), 271; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060271 - 10 Jun 2022
Cited by 3 | Viewed by 1733
Abstract
n-Dodecane has been investigated as an oxygen-vector for improving α-amylase biosynthesis using the strain Aspergillus terreus. In aerobic microbial cultivation, continuous supply of oxygen is required especially due to its low solubility in the growth medium, in particular at high viscosity, [...] Read more.
n-Dodecane has been investigated as an oxygen-vector for improving α-amylase biosynthesis using the strain Aspergillus terreus. In aerobic microbial cultivation, continuous supply of oxygen is required especially due to its low solubility in the growth medium, in particular at high viscosity, but the limitations of oxygen mass transfer in these systems can be overcome by the addition of water-insoluble compounds which possess a strong affinity for oxygen, namely oxygen-vectors. The use of n-dodecane (as an oxygen-vector) in the fermentation medium of A. terreus can significantly improve the bioprocess performance and enhance α-amylase production. Using 5% n-dodecane at 35 °C, an increase of 1.8–2 times in the enzymatic activity was recorded. In the oxygen-vector’s absence, the highest amount of biomass was obtained at 35 °C, while in the presence of 5% vol. n-dodecane, the amount of fungal biomass increased by approximately 70%, with a shift in optimum temperature to 40 °C, generating also an enzymatic activity increase of 2.30 times. Moreover, the oxygen-vector’s addition in the fermentation broth influenced the fungal morphological development in the form of larger pellets with a more compact structure compared to the system without n-dodecane, with a positive effect on the fermentation performance (higher α-amylase activity production). Full article
(This article belongs to the Special Issue New Research on Fungal Secondary Metabolites)
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17 pages, 1776 KiB  
Article
Inhibitory and Stimulatory Effects of Fruit Bioactive Compounds on Edible Filamentous Fungi: Potential for Innovative Food Applications
by Gülru Bulkan, Gerarda Tania Yudhanti, Sitaresmi Sitaresmi, Ria Millati, Rachma Wikandari and Mohammad J. Taherzadeh
Fermentation 2022, 8(6), 270; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060270 - 09 Jun 2022
Cited by 2 | Viewed by 2450
Abstract
The fermentation of fruit processing residuals (FPRs) with filamentous fungi can provide protein-rich food products. However, FPRs that contain bioactive compounds with antimicrobial properties present a major challenge. In this work, the resistance of two edible filamentous fungi, Rhizopus oligosporus and Neurospora intermedia [...] Read more.
The fermentation of fruit processing residuals (FPRs) with filamentous fungi can provide protein-rich food products. However, FPRs that contain bioactive compounds with antimicrobial properties present a major challenge. In this work, the resistance of two edible filamentous fungi, Rhizopus oligosporus and Neurospora intermedia, to 10 typically inhibiting bioactive compounds available in FPRs (epicatechin, quercetin, ellagic acid, betanin, octanol, hexanal, D-limonene, myrcene, car-3-ene, and ascorbic acid) was examined. These compounds’ inhibitory and stimulatory effects on fungal growth were examined individually. Three different concentrations (2.4, 24, and 240 mg/L) within the natural concentration range of these compounds in FPRs were tested. These bioactive compounds stimulated the growth yield and glucose consumption rate of R. oligosporus, while there was no increase in the biomass yield of N. intermedia. Ellagic acid caused an up to four-fold increase in the biomass yield of R. oligosporus. In addition, octanol and D-limonene showed antifungal effects against N. intermedia. These results may be helpful in the development of fungus-based novel fermented foods. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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18 pages, 1815 KiB  
Article
Effects of Fermented Camel Milk Supplemented with Sidr Fruit (Ziziphus spina-christi L.) Pulp on Hyperglycemia in Streptozotocin-Induced Diabetic Rats
by El Sayed Hassan Atwaa, Magdy Ramadan Shahein, Barakat M. Alrashdi, Moustafa A. A. Hassan, Mohamed A. Alblihed, Naief Dahran, Fatma Abo Zakaib Ali and Ehab Kotb Elmahallawy
Fermentation 2022, 8(6), 269; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060269 - 08 Jun 2022
Cited by 6 | Viewed by 2789
Abstract
Diabetes is one of the most common chronic metabolic diseases, and its occurrence rate has increased in recent decades. Sidr (Ziziphus spina-christi L.) is a traditional herbaceous medicinal plant. In addition to its good flavor, sidr has antidiabetic, anti-inflammatory, sedative, analgesic, and [...] Read more.
Diabetes is one of the most common chronic metabolic diseases, and its occurrence rate has increased in recent decades. Sidr (Ziziphus spina-christi L.) is a traditional herbaceous medicinal plant. In addition to its good flavor, sidr has antidiabetic, anti-inflammatory, sedative, analgesic, and hypoglycemic activities. Camel milk has a high nutritional and health value, but its salty taste remains the main drawback in relation to its organoleptic properties. The production of flavored or fortified camel milk products to mask the salty taste can be very beneficial. This study aimed to investigate the effects of sidr fruit pulp (SFP) on the functional and nutritional properties of fermented camel milk. SFP was added to camel milk at rates of 5%, 10%, and 15%, followed by the selection of the best-fermented product in terms of functional and nutritional properties (camel milk supplemented with 15% SFP), and an evaluation of its hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats. Thirty-two male adult albino rats (weighing 150–185 g) were divided into four groups: Group 1, nontreated nondiabetic rats (negative control); Group 2, diabetic rats given STZ (60 mg/kg body weight; positive control); Group 3, diabetic rats fed a basal diet with fermented camel milk (10 g/day); and Group 4, diabetic rats fed a basal diet with fermented camel milk supplemented with 15% SFP (10 g/day). The results revealed that supplementation of camel milk with SFP increased its total solids, protein, ash, fiber, viscosity, phenolic content, and antioxidant activity, which was proportional to the supplementation ratio. Fermented camel milk supplemented with 15% SFP had the highest scores for sensory properties compared to other treatments. Fermented camel milk supplemented with 15% SFP showed significantly decreased (p < 0.05) blood glucose, malondialdehyde, low-density lipoprotein-cholesterol, cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, creatinine, and urea, and a significantly increased (p < 0.05) high-density lipoprotein-cholesterol, total protein content, and albumin compared to diabetic rats. The administration of fermented camel milk supplemented with 15% SFP in diabetic rats restored a series of histopathological changes alonsgside an improvement in various enzyme and liver function tests compared to the untreated group, indicating that fermented camel milk supplemented with 15% SFP might play a preventive role in such patients. Full article
(This article belongs to the Special Issue Production of Pharmaceuticals and Nutraceuticals by Fermentation)
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11 pages, 889 KiB  
Article
Development and Analysis of an Intensified Batch-Fed Wine Fermentation Process
by Konrad V. Miller, Even Arefaine, Ardic Arikal, Annegret Cantu, Raul Cauduro Girardello, Anita Oberholster, Hildegarde Heymann and David E. Block
Fermentation 2022, 8(6), 268; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060268 - 07 Jun 2022
Viewed by 2275
Abstract
White wine fermentations are typically performed in an entirely batchwise manner, with yeast nutrients only added at the beginning of fermentation. This leads to slow (2+ weeks) fermentation cycle times, with large capital expenditures required to increase winery processing capacity. Prior attempts to [...] Read more.
White wine fermentations are typically performed in an entirely batchwise manner, with yeast nutrients only added at the beginning of fermentation. This leads to slow (2+ weeks) fermentation cycle times, with large capital expenditures required to increase winery processing capacity. Prior attempts to speed fermentations via increasing temperature have resulted in unpalatable wine, and continuous fermentation processing is uneconomical and impractical in the winery setting. In this work, we measured yeast nutrient consumption as a function of fermentation progression at the 300 mL scale, and from this derived an equation to optimize yeast nutrient concentration as a function of fermentation progression. These findings were applied at the pilot scale in 150 L fermentors, which resulted in a 60% cycle time reduction versus “best practices” control fermentations. The resultant wines were compared via GC-MS as well as by a trained sensory panel. Organoleptic analysis found statistically significant, but overall, small differences in sensory characteristics between the control and process intensified wines. This intensified fermentation process shows great promise for fermented beverage producers wishing to maximize equipment utilization and debottleneck wineries or other beverage fermentation facilities. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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16 pages, 612 KiB  
Article
Antidiabetic and Hypolipidemic Efficiency of Lactobacillus plantarum Fermented Oat (Avena sativa) Extract in Streptozotocin-Induced Diabetes in Rats
by Raya Algonaiman, Hend F. Alharbi and Hassan Barakat
Fermentation 2022, 8(6), 267; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060267 - 06 Jun 2022
Cited by 15 | Viewed by 2933
Abstract
Antidiabetic properties of fermented foods have been previously demonstrated. This study aimed to examine the antidiabetic and hypolipidemic potential activities of L. plantarum fermented oat extract in Streptozotocin-induced diabetic rats. Firstly, inoculating 1% of L. plantarum starter culture in 10% whole oat flour [...] Read more.
Antidiabetic properties of fermented foods have been previously demonstrated. This study aimed to examine the antidiabetic and hypolipidemic potential activities of L. plantarum fermented oat extract in Streptozotocin-induced diabetic rats. Firstly, inoculating 1% of L. plantarum starter culture in 10% whole oat flour in aqueous media resulted in 8.36 log CFU mL−1 and pH 4.60 after 72 h of fermentation at 37 °C. With time progression of oat fermentation, total phenolic content (TPC), antioxidant activity (AOA), and γ-aminobutyric acid (GABA) contents were significantly increased up to 72 h. On the contrary, a significant reduction in β-glucan content was observed only after 72 h of fermentation. Secondly, separated aqueous extracts, i.e., unfermented oat extract (UFOE) and L. plantarum fermented oat extract (LFOE) were examined in vivo in a rat model, which consisted of five groups. Group 1 (negative group, NR); GROUP 2 (positive group, STZ), intraperitoneally injected with a single dose of 45 mg kg−1 BW of Streptozotocin and administered 7 mL of distilled water orally per day; Group 3 (STZ+MET), diabetic rats orally administered 50 mg of metformin kg−1 BW daily; Group 4 (STZ+UFOE), diabetic rats orally administered 7 mL of UFOE daily; and Group 5 (STZ+UFOE), diabetic rats orally administered 7 mL of LFOE daily for 6 weeks. Monitoring random blood glucose (RBG) and fasting blood glucose (FBG) showed that both the UFOE and the LFOE alleviated hyperglycemia in the STZ-induced diabetic rats. The extracts were significantly efficient in improving serum lipid profiles as compared with the positive group. Moreover, liver and kidneys’ functions were improved, and both extracts promoted hepatoprotective and nephroprotective characteristics. Furthermore, the administration of the UFOE and the LFOE efficiently attenuated GSH, CAT, and SOD enzymes and decreased MDA levels as compared with the positive group. In conclusion, data indicate the potential of UFOE and LFOE in future strategies as functional supplements against diabetes and diabetes-related complications. Full article
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16 pages, 1331 KiB  
Article
Changes in Flavor- and Aroma-Related Fermentation Metabolites and Antioxidant Activity of Glutinous Rice Wine Supplemented with Chinese Chestnut (Castanea mollissima Blume)
by Jing Zou, Yinan Ge, Yue Zhang, Min Ding, Kuo Li, Yinglan Lin, Xuedong Chang, Fei Cao and Yunkai Qian
Fermentation 2022, 8(6), 266; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060266 - 06 Jun 2022
Cited by 4 | Viewed by 3099
Abstract
Traditional glutinous rice wine (TGRW) has been fermented in China for over 9000 years. Recently, an innovative regional variation of TGRW, chestnut rice wine, banli mijiu (BLMJ), was developed by adding Chinese chestnut (Castanea mollissima Blume) into the fermentation brew. The objective [...] Read more.
Traditional glutinous rice wine (TGRW) has been fermented in China for over 9000 years. Recently, an innovative regional variation of TGRW, chestnut rice wine, banli mijiu (BLMJ), was developed by adding Chinese chestnut (Castanea mollissima Blume) into the fermentation brew. The objective of this study was to characterize the effects of chestnut on the nutritional, aromatic, and antioxidant properties of TGRW. To compare the aromatic sensory profiles between TGRW and BLMJ, the free amino acids and ethyl carbamate, phenolic, and flavonoid contents were determined. In addition, the antioxidant properties, including reducing power, metal chelation, and free radical scavenging activities, were also compared. A total of 98 distinct flavor components were identified in BLMJ, among which 38 were detected by sniffing instrument, compared to 77 distinct flavor components in TGRW. BLMJ thus contains a wider range of flavor components, but similar alcohol, acid and reducing sugar profiles compared with TGRW. Twenty-five free amino acids were detected in both wines, with lower contents of each in BLMJ compared with TGRW. BLMJ also exhibited stronger antioxidant properties than TGRW. The findings of this study suggest that chestnut can increase the diversity of aromatic components and improve antioxidant qualities of traditional rice wine. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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9 pages, 1052 KiB  
Article
Inactivation of Endogenous Pectin Methylesterases by Radio Frequency Heating during the Fermentation of Fruit Wines
by Yan Zhao, Xiaobin Yu, Wei Zhao, Gen Li, Guangpeng Liu, Yanrui Ma, Le Chu, Yinfei Ma, Ying Zhang, Yao Lu, Fatao He and Xiaobo Liu
Fermentation 2022, 8(6), 265; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060265 - 06 Jun 2022
Cited by 2 | Viewed by 1782
Abstract
Pectin methylesterase (PME) is a methyl ester group hydrolytic enzyme of either plant or microbial origin. Importantly, endogenous PMEs in fruits can catalyze the demethoxylation of pectin with a bulk release of methanol, largely impacting the fruit juice and wine industries. Here, we [...] Read more.
Pectin methylesterase (PME) is a methyl ester group hydrolytic enzyme of either plant or microbial origin. Importantly, endogenous PMEs in fruits can catalyze the demethoxylation of pectin with a bulk release of methanol, largely impacting the fruit juice and wine industries. Here, we demonstrated radio frequency (RF) heating for inactivation of endogenous PMEs and investigated the relevant mechanisms underpinning enzymatic inactivation. The RF heating curve indicated that the optimal heating rate was achieved at an electrode gap of 90 mm (compared to 100 mm and 110 mm) and that the inactivation rate of the enzyme increases with heating time. RF heating exhibited better effects on enzymatic inactivation than traditional water heating, mainly by changing the secondary structures of PMEs, including α-helix, β-sheet, β-turn, and random coil. Moreover, fluorescence spectroscopy indicated changes in the tertiary structure with a significant increase in fluorescence intensity. Significantly, application of RF heating for inactivation of PMEs resulted in a 1.5-fold decrease in methanol during the fermentation of jujube wine. Collectively, our findings demonstrated an effective approach for inactivating endogenous PMEs during the bioprocesses of fruits. Full article
(This article belongs to the Special Issue New Aspect on Wine Fermentation)
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13 pages, 4120 KiB  
Article
Nutrition Component Adjustment of Distilled Dried Grain with Solubles via Aspergillus niger and Its Change about Dynamic Physiological Metabolism
by Weiwei Fan, Xuhui Huang, Kehan Liu, Yongping Xu, Bo Hu and Zhanyou Chi
Fermentation 2022, 8(6), 264; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060264 - 05 Jun 2022
Cited by 4 | Viewed by 1831
Abstract
The low fiber digestibility and unbalanced amino acids restricted the use of DDGS in swine diets. Key nutrition components dynamic monitoring and key regulatory pathways analysis were performed to find the rules of nutrition changes for DDGS fermented by Aspergillus niger. Cellulose [...] Read more.
The low fiber digestibility and unbalanced amino acids restricted the use of DDGS in swine diets. Key nutrition components dynamic monitoring and key regulatory pathways analysis were performed to find the rules of nutrition changes for DDGS fermented by Aspergillus niger. Cellulose and hemicellulose were reduced to 15.3% and 15.2%. 1,4-D-Xylobiose was decreased from 16.8 μg/mL to 0.2 μg/mL. Lys, Arg, and Thr were increased to 3.00%, 2.89%, and 4.40%, and met the requirements of pigs. The whole fermentation process was divided into three stages. Cellulose degradation and Lys and Arg synthesis occurred in the early stage, while Asp synthesis occurred in the last stage. α-Ketoglutarate was the key factor for Aspergillus niger degrading cellulose to synthesize Lys and Arg. The key active metabolic pathways that respond to the changes in nutrition were identified which preliminarily revealed the rules of nutrition adjustment of DDGS during fermentation with Aspergillus niger. Full article
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13 pages, 2036 KiB  
Article
Improving Ergometrine Production by easO and easP Knockout in Claviceps paspali
by Yun-Ming Qiao, Yan-Hua Wen, Ting Gong, Jing-Jing Chen, Tian-Jiao Chen, Jin-Ling Yang and Ping Zhu
Fermentation 2022, 8(6), 263; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060263 - 02 Jun 2022
Cited by 4 | Viewed by 1981
Abstract
Ergometrine is widely used for the treatment of excessive postpartum uterine bleeding. Claviceps paspali is a common species for industrial production of ergometrine, which is often accompanied by lysergic acid α-hydroxyethylamide (LAH) and lysergic acid amide (LAA). Currently, direct evidence on the [...] Read more.
Ergometrine is widely used for the treatment of excessive postpartum uterine bleeding. Claviceps paspali is a common species for industrial production of ergometrine, which is often accompanied by lysergic acid α-hydroxyethylamide (LAH) and lysergic acid amide (LAA). Currently, direct evidence on the biosynthetic mechanism of LAH and LAA from lysergic acid in C. paspali is absent, except that LAH and LAA share the common precursor with ergometrine and LAA is spontaneously transformed from LAH. A comparison of the gene clusters between C. purpurea and C. paspali showed that the latter harbored the additional easO and easP genes. Thus, the knockout of easO and easP in the species should not only improve the ergometrine production but also elucidate the function. In this study, gene knockout of C. paspali by homologous recombination yielded two mutants ∆easOhetero-1 and ∆easPhetero-34 with ergometrine titers of 1559.36 mg∙L−1 and 837.57 mg∙L−1, which were four and two times higher than that of the wild-type control, respectively. While the total titer of LAH and LAA of ∆easOhetero-1 was lower than that of the wild-type control. The Aspergillus nidulans expression system was adopted to verify the function of easO and easP. Heterologous expression in A. nidulans further demonstrated that easO, but not easP, determines the formation of LAA. Full article
(This article belongs to the Special Issue Fermentation and Bioactive Metabolites 3.0)
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14 pages, 3165 KiB  
Article
Fermentation Quality, Bacterial Community, and Aerobic Stability of Perennial Recut Broussonetia papyrifera Silage with Different Additives and Wilting Time
by Jun Hao, Wen-Tao Sun, Chang-Rong Wu, Ming-Zhu Zhang, Guang-Hao Xia, Yu-Long Zheng and Chao Chen
Fermentation 2022, 8(6), 262; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation8060262 - 02 Jun 2022
Cited by 6 | Viewed by 1895
Abstract
Broussonetia papyrifera L. (paper mulberry) is an alternative woody plant, which can used to replace part of the protein feed for ruminants. Ensiling is an effective way to preserve fresh pasture and to solve the problem of stable storage and feed conversion of [...] Read more.
Broussonetia papyrifera L. (paper mulberry) is an alternative woody plant, which can used to replace part of the protein feed for ruminants. Ensiling is an effective way to preserve fresh pasture and to solve the problem of stable storage and feed conversion of paper mulberry in the rapid growth period. However, low dry matter (DM), water-soluble carbohydrate, and lactic acid bacteria (LAB) reduce the quality of paper mulberry silage. This study assesses the influence of wilting time (0 h and 3.5 h; lighting: 3.43 × 104 Lux) and three additives (Enterococcus durans, CL; cellulase, CE; and formic acid, FA) on the fermentation quality, aerobic stability, and bacterial community of whole plant B. papyrifera silage. The whole plant B. papyrifera sample was mowed and wilted for 0 h and 3.5 h, and then had CL, CE, or FA added, followed by 60 days of ensiling. The results show all silage samples had high fermentation quality with pH below 4.2, ammonia-nitrogen below 100 g/kg DM, and no detectable butyric acid. The additives protected the DM and the crude protein from protease activity (p < 0.05), and CL was the most effective among them. Furthermore, wilting time influenced the silage’s bacterial communities, but overall, CL treatment had the greatest impact on bacterial communities. Wilting time and formic acid treatment significantly improved aerobic stability (p < 0.05). Enterococcus was positively correlated with lactic acid (LA), while negatively correlated with LA and Weissella (p < 0.001). Enterococcus was identified as the main driver of the whole plant paper mulberry ensiling process in the present study. In conclusion, compared to other additives, LAB is the most effective and economical to improve the fermentation quality and reduce the protein degradation of whole plant paper mulberry silage. Our findings provide a theoretical basis to improve the quality and production of paper mulberry silage. Full article
(This article belongs to the Special Issue Silage Fermentation)
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