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Fermentation, Volume 10, Issue 5 (May 2024) – 43 articles

Cover Story (view full-size image): The following study explores the potential to expand the butter market by introducing newer variants of butter with enhanced health benefits. The survival patterns of two probiotic organisms, Lactobacillus acidophilus (LA5) and Bifidobacterium animalis ssp. lactis (BB12), in both free-cell and encapsulated forms, were studied in the butter matrix. In addition to viability studies, mathematical equations were developed to predict viable counts of probiotics during butter storage. This study provides insights into the improved survival of WPH-MD-encapsulated probiotics and the application of mathematical equations to study the population changes of probiotics during storage. View this paper
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18 pages, 3366 KiB  
Article
The Effect of Non-Saccharomyces Cerevisiae Torulaspora delbrueckii on the Aroma Composition of Munage Grape Base-Wine and the Mechanism of the Effect
by Xuefeng Yin, Bingze Liu, Ruxianguli Maimaitiyiming, Liang Wang, Lei Zhao, Huimin Zhang, Keping Chen and Aihemaitijiang Aihaiti
Fermentation 2024, 10(5), 266; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050266 - 20 May 2024
Viewed by 495
Abstract
To enhance comprehension of the impact of mixed fermentation using Torulaspora delbrueckii Bio-119667 (TD) on the aroma composition of Munage grape base-wine (MGBW), we analysed the aroma composition of MGBW using HS-SPME-GC-MS widely targeted metabolomics. The levels of volatile aroma components, including terpenes, [...] Read more.
To enhance comprehension of the impact of mixed fermentation using Torulaspora delbrueckii Bio-119667 (TD) on the aroma composition of Munage grape base-wine (MGBW), we analysed the aroma composition of MGBW using HS-SPME-GC-MS widely targeted metabolomics. The levels of volatile aroma components, including terpenes, higher alcohols, aldehydes, heterocyclic compounds, and esters, were significantly higher in MGBW produced by mixed fermentation compared to the pure Saccharomyces yeast control fermentation. The study found that the content of esters increased by 26.3% after mixed fermentation, indicating the contribution of TD to the formation of ester flavour components during the fermentation of MGBW. After analysing aroma activity values, we discovered that 49 out of 115 esters (25.5% of the total) significantly contributed to the aroma profile of MGBW (rOAV > 1). Of these esters, 16 were identified as key aroma compounds (rOAV > 1, VIP > 1) produced by mixed fermentation with the participation of TD. This finding further supports the contribution of TD to the improvement of MGBW’s aroma composition. This study reveals the role of non-Saccharomyces yeast strain Torulaspora delbrueckii Bio-119667 in improving the aroma composition of MGBW produced by mixed culture fermentation and the biosynthetic pathways of key aroma components therein. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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17 pages, 3075 KiB  
Article
New Solutions in Single-Cell Protein Production from Methane: Construction of Glycogen-Deficient Mutants of Methylococcus capsulatus MIR
by Sergey Y. But, Ruslan Z. Suleimanov, Igor Y. Oshkin, Olga N. Rozova, Ildar I. Mustakhimov, Nikolai V. Pimenov, Svetlana N. Dedysh and Valentina N. Khmelenina
Fermentation 2024, 10(5), 265; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050265 - 19 May 2024
Viewed by 644
Abstract
The biotechnology of converting methane to single-cell protein (SCP) implies using fast-growing thermotolerant aerobic methanotrophic bacteria. Among the latter, members of the genus Methylococcus received significant research attention and are used in operating commercial plants. Methylococcus capsulatus MIR is a recently discovered member [...] Read more.
The biotechnology of converting methane to single-cell protein (SCP) implies using fast-growing thermotolerant aerobic methanotrophic bacteria. Among the latter, members of the genus Methylococcus received significant research attention and are used in operating commercial plants. Methylococcus capsulatus MIR is a recently discovered member of this genus with the potential to be used for the purpose of SCP production. Like other Methylococcus species, this bacterium stores carbon and energy in the form of glycogen, particularly when grown under nitrogen-limiting conditions. The genome of strain MIR encodes two glycogen synthases, GlgA1 and GlgA2, which are only moderately related to each other. To obtain glycogen-free cell biomass of this methanotroph, glycogen synthase mutants, ΔglgA1, ΔglgA2, and ΔglgA1ΔglgA2, were constructed. The mutant lacking both glycogen synthases exhibited a glycogen-deficient phenotype, whereas the intracellular glycogen content was not reduced in strains defective in either GlgA1 or GlgA2, thus suggesting functional redundancy of these enzymes. Inactivation of the glk gene encoding glucokinase also resulted in a sharp decrease in glycogen content and accumulation of free glucose in cells. Wild-type strain MIR and the mutant strain ΔglgA1ΔglgA2 were also grown in a bioreactor operated in batch and continuous modes. Cell biomass of ΔglgA1ΔglgA2 mutant obtained during batch cultivation displayed high protein content (71% of dry cell weight (DCW) compared to 54% DCW in wild-type strain) as well as a strong reduction in glycogen content (10.8 mg/g DCW compared to 187.5 mg/g DCW in wild-type strain). The difference in protein and glycogen contents in biomass of these strains produced during continuous cultivation was less pronounced, yet biomass characteristics relevant to SCP production were slightly better for ΔglgA1ΔglgA2 mutant. Genome analysis revealed the presence of glgA1-like genes in all methanotrophs of the Gammaproteobacteria and Verrucomicrobia, while only a very few methanotrophic representatives of the Alphaproteobacteria possessed these determinants of glycogen biosynthesis. The glgA2-like genes were present only in genomes of gammaproteobacterial methanotrophs with predominantly halo- and thermotolerant phenotypes. The role of glycogen in terms of energy reserve is discussed. Full article
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18 pages, 1465 KiB  
Article
In Vitro Probiotic Characterization of Lactiplantibacillus plantarum Strains Isolated from Traditional Fermented Dockounou Paste
by Natia Joseph Kouadio, Alalet Luc Olivier Zady, Kouassi Aboutou Séverin Kra, Filofteia Camelia Diguță, Sébastien Niamke and Florentina Matei
Fermentation 2024, 10(5), 264; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050264 - 19 May 2024
Viewed by 559
Abstract
This study aimed to evaluate the probiotic properties of 10 lactic acid bacteria (LAB) isolated from artisanal fermented plantain dockounou paste. A preliminary characterization of the LAB isolates was performed based on phenotypic and several biochemical properties, which was subsequently confirmed through 16S [...] Read more.
This study aimed to evaluate the probiotic properties of 10 lactic acid bacteria (LAB) isolated from artisanal fermented plantain dockounou paste. A preliminary characterization of the LAB isolates was performed based on phenotypic and several biochemical properties, which was subsequently confirmed through 16S rRNA gene sequencing analysis, indicating that these isolates belonged to the species Lactiplantibacillus plantarum. With regard to safety criteria, the strains exhibited no alpha or beta hemolysis activity. Nevertheless, the majority of LAB strains demonstrated high sensitivity to the antibiotics tested. The results demonstrated that the majority of the strains exhibited remarkably high survival rates under simulated gastrointestinal conditions, such as pH = 1.5 (81.18–98.15%), 0.3% bile salts (68.62–100.89%), 0.4% phenol (40.59–128.24%), as well as 0.1% pepsin and pH = 2.5 (88.54–99.78%). The LAB strains demonstrated elevated levels of cell surface properties, indicative of the presence of a considerable defensive mechanism against pathogens. Intact LAB cells exhibited significant antioxidant abilities (48.18–83.58%). They also demonstrated a pronounced inhibitory effect on the growth of foodborne pathogens. Enzyme pattern analysis revealed that the LAB isolates produced both proteases and cellulases, as well as pectinase and/or amylase activity. The potential of the L. plantarum strains FS43, FS44, and FS48, as indicated by the results obtained from the standard in vitro assays, makes them suitable for further study as potential probiotics. Full article
(This article belongs to the Special Issue Applications of Lactic Acid Bacteria in Fermented Foods and Beverages)
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30 pages, 8540 KiB  
Review
Yarrowia lipolytica Yeast: A Treasure Trove of Enzymes for Biocatalytic Applications—A Review
by Bartłomiej Zieniuk, Karina Jasińska, Katarzyna Wierzchowska, Şuheda Uğur and Agata Fabiszewska
Fermentation 2024, 10(5), 263; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050263 - 18 May 2024
Viewed by 877
Abstract
Yarrowia lipolytica is a robust yeast species that has gained significant attention as a biofactory for various biotechnological applications and undoubtedly can be referred to as a hidden treasure trove due to boasting a diverse array of enzymes with wide-ranging applications in multiple [...] Read more.
Yarrowia lipolytica is a robust yeast species that has gained significant attention as a biofactory for various biotechnological applications and undoubtedly can be referred to as a hidden treasure trove due to boasting a diverse array of enzymes with wide-ranging applications in multiple industries, including biofuel production, food processing, biotechnology, and pharmaceuticals. As the biotechnology field continues to expand, Y. lipolytica is poised to play a pivotal role in developing eco-friendly and economically viable bioprocesses. Its versatility and potential for large-scale production make it a promising candidate for sustainably addressing various societal and industrial needs. The current review article aimed to highlight the diverse enzymatic capabilities of Y. lipolytica and provide a detailed analysis of its relevance in biocatalysis, including the use of whole-cell catalysts and isolated enzymes. The review focused on wild-type yeast strains and their species-dependant properties and selected relevant examples of Y. lipolytica used as a host organism for overexpressing some enzymes. Furthermore, the application of Y. lipolytica’s potential in enantiomers resolution, lipids processing, and biodiesel synthesis, as well as the synthesis of polymers or esterification of different substrates for upgrading biologically active compounds, was discussed. Full article
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17 pages, 5778 KiB  
Article
Response of Anaerobic Granular Sludge Reactor to Plant Polyphenol Stress: Floc Disintegration and Microbial Inhibition
by Shilin Bi, Hua Lian, Huiya Zhang, Zexiang Liu, Yong Chen and Jian Zhang
Fermentation 2024, 10(5), 262; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050262 - 17 May 2024
Viewed by 514
Abstract
Plant polyphenols are potential inhibitors for the anaerobic treatment of wastewater from the wood processing, pharmaceutical, and leather industries. Tannic acid (TA) was selected as a model compound to assess the inhibitory effect of plant polyphenols in simulated wastewater in this study. The [...] Read more.
Plant polyphenols are potential inhibitors for the anaerobic treatment of wastewater from the wood processing, pharmaceutical, and leather industries. Tannic acid (TA) was selected as a model compound to assess the inhibitory effect of plant polyphenols in simulated wastewater in this study. The influences of TA on methanogenic activity, sludge morphology, and the microbial community were investigated under glucose and sodium acetate as carbon substrates, respectively. The results show that a threshold concentration of TA above 1500 mg·L−1 that triggers significant methanogenesis depression and volatile fatty acids (VFAs) accumulation. In addition, granules might be weakened by TA addition, reflected in changes in extracellular polymeric substances (EPS) within the granules and an increase in floc in the effluent. The anaerobic granular sludge (AnGS) fed with sodium acetate was more sensitive than the presence of glucose as the substrate when facing the challenge of TA. The concentration of the mcrA gene in granular sludge decreased markedly in response to TA stress, providing direct evidence that a high concentration of TA caused the inhibition of specific gene expressions. This study provides details about the adverse impacts of TA stress on methane production, the microbial community, and granule integrity, deepening our understanding of the anaerobic treatment of plant polyphenols contained in wastewater. Full article
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12 pages, 1564 KiB  
Article
Biogas Production Potential of Mixed Banana and Pineapple Waste as Assessed by Long-Term Laboratory-Scale Anaerobic Digestion
by Vita Aleksandrovna Rabinovich, Carsten Linnenberg, Ulf Theilen and Harald Weigand
Fermentation 2024, 10(5), 261; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050261 - 16 May 2024
Viewed by 626
Abstract
Biogas is a renewable energy source generated through the anaerobic digestion (AD) of organic feedstocks. This study aims to quantify the biogas production potential (BPP) of fruit wastes via semi-continuous lab-scale mesophilic AD over a total of 100 days. The feed was composed [...] Read more.
Biogas is a renewable energy source generated through the anaerobic digestion (AD) of organic feedstocks. This study aims to quantify the biogas production potential (BPP) of fruit wastes via semi-continuous lab-scale mesophilic AD over a total of 100 days. The feed was composed of 80% banana peelings and 20% pineapple residues, mimicking the waste composition of a Costa Rican fruit processing facility used as a test case. The average loading rate of volatile suspended solids (VSS) corresponded to 3.6 kg VSS·m−3·d−1. Biogas yield and composition were monitored, along with the concentration of ammonium, volatile fatty acids, and pH. Discounting the start-up phase, the BPP averaged to 526 LN (kg VSS)−1 with a methane concentration of around 54%, suggesting suitability of the substrate for AD. We calculated that if upscaled to the Costa Rican test case facility, these values translate into a gross average heat and electricity production via AD of around 5100 MWhel·a−1 and 5100 MWhth·a−1, respectively. Deducting self-consumption of the AD treatment, this is equivalent to 73% of the facility’s electricity demand, and could save about 450,000 L of heavy oil per year for heat generation. To circumvent nitrogen shortage, the addition of a co-substrate such as dry manure seems advisable. Full article
(This article belongs to the Special Issue Anaerobic Digestion: Waste to Energy)
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13 pages, 2252 KiB  
Article
Fermentation of Sugar by Thermotolerant Hansenula polymorpha Yeast for Ethanol Production
by Adnan Asad Karim, Mª Lourdes Martínez-Cartas and Manuel Cuevas-Aranda
Fermentation 2024, 10(5), 260; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050260 - 16 May 2024
Viewed by 593
Abstract
Hansenula polymorpha is a non-conventional and thermo-tolerant yeast that is well-known for its use in the industrial production of recombinant proteins. However, research to evaluate this yeast’s potential for the high-temperature fermentation of sugar to produce alcohols for biofuel applications is limited. The [...] Read more.
Hansenula polymorpha is a non-conventional and thermo-tolerant yeast that is well-known for its use in the industrial production of recombinant proteins. However, research to evaluate this yeast’s potential for the high-temperature fermentation of sugar to produce alcohols for biofuel applications is limited. The present work investigated a wild-type H. polymorpha strain (DSM 70277) for the production of ethanol at a temperature of 40 °C under limited oxygen presence by using a batch fermentation reactor. Fermentation experiments were performed using three types of sugar (glucose, fructose, xylose) as substrates with two initial inoculum concentrations (1.1 g·L−1 and 5.0 g·L−1). The maximum specific growth rates of H. polymorpha yeast were 0.121–0.159 h−1 for fructose, 0.140–0.175 h−1 for glucose, and 0.003–0.009 h−1 for xylose. The biomass volumetric productivity was 0.270–0.473 g·L−1h−1 (fructose), 0.185–0.483 g·L−1h−1 (glucose), and 0.001–0.069 g·L−1h−1 (xylose). The overall yield of ethanol from glucose (0.470 g·g−1) was higher than that from fructose (0.434 g·g−1) and xylose (0.071 g·g−1). The H. polymorpha yeast exhibited different behavior and efficacy regarding the use of glucose, fructose, and xylose as substrates for producing ethanol. The present knowledge could be applied to improve the fermentation process for valorization of waste biomass to produce bioethanol. Full article
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13 pages, 1628 KiB  
Article
Antioxidant and Anticancer Potential of Extracellular Polysaccharide from Porphyridium aerugineum (Rhodophyta)
by Juliana G. Ivanova, Tanya S. Toshkova-Yotova, Reneta A. Toshkova, Veronika R. Deleva, Ani K. Georgieva and Liliana G. Gigova
Fermentation 2024, 10(5), 259; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050259 - 15 May 2024
Viewed by 704
Abstract
Porphyridium aerugineum is a unicellular freshwater red microalga that synthesizes and secretes into the culture medium an extracellular polysaccharide (EPS). In this study, algal growth and polysaccharide production, as well as the antioxidant capacity and antitumor effect of Porphyridium aerugineum EPS (PaEPS), were [...] Read more.
Porphyridium aerugineum is a unicellular freshwater red microalga that synthesizes and secretes into the culture medium an extracellular polysaccharide (EPS). In this study, algal growth and polysaccharide production, as well as the antioxidant capacity and antitumor effect of Porphyridium aerugineum EPS (PaEPS), were investigated. Cultivation of the microalgae was carried out in a photobioreactor under controlled conditions. Algal growth and the amount of EPS were monitored daily. The accumulated polysaccharide was extracted and lyophilized. At the end of cultivation, the concentration of microalgal biomass and PaEPS reached 3.3 and 1.2 g L−1, respectively. To examine the antioxidant capacity of PaEPS, FRAP and ABTS assays were performed. The cytotoxic activity of PaEPS was evaluated on the tumor cell lines MCF-7 (breast cancer) and HeLa (cervical adenocarcinoma) and on BJ (a non-tumor human skin fibroblast cell line), using MTT assay. The results obtained indicated that P. aerugineum polysaccharide exhibited a high ABTS radical-scavenging activity reaching up to 55%. The cytotoxic effect was best expressed in MCF-7 cells treated for 72 h with 1000 µg/mL PaEPS, where tumor cell proliferation was inhibited by more than 70%. Importantly, the PaEPS treatments did not significantly affect the viability of BJ cells. These findings promote the biotechnological production of P. aerugineum extracellular polysaccharide and reveal its potential as an anticancer and antioxidant agent for future applications. Full article
(This article belongs to the Special Issue Cyanobacteria and Eukaryotic Microalgae)
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31 pages, 1252 KiB  
Review
Exploring Sustainable Aquafeed Alternatives with a Specific Focus on the Ensilaging Technology of Fish Waste
by Anastasiia Maksimenko, Leonid Belyi, Anna Podvolotskaya, Oksana Son and Liudmila Tekutyeva
Fermentation 2024, 10(5), 258; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050258 - 15 May 2024
Viewed by 890
Abstract
The global increase in population has placed significant pressure on food security, leading to the emergence of aquaculture as a vital source of aquatic foods. However, rising costs and limited fish meal availability in aquafeeds have driven the search for alternative protein sources. [...] Read more.
The global increase in population has placed significant pressure on food security, leading to the emergence of aquaculture as a vital source of aquatic foods. However, rising costs and limited fish meal availability in aquafeeds have driven the search for alternative protein sources. While plant-based ingredients have been integrated into commercial aquafeeds, they come with challenges such as low protein content, palatability issues, and the presence of antinutritional factors. In this context, fish silage, made from fish waste and discarded fish, stands out as a promising alternative technology due to its cost-effectiveness and sustainability attributes. The production of fish silage involves the addition of organic/inorganic acids or lactic acid bacteria to homogenized fish waste, yielding a valuable mixture rich in peptides and free amino acids, offering significant nutritional benefits for animal diets. This review aims to promote sustainable practices in the aquaculture industry by analyzing research results related to ensiling technology, appraising the advantages and disadvantages of using fish silage as a feed ingredient, and focusing on emerging trends in this field. Full article
(This article belongs to the Special Issue Fermentation Technologies for the Production of High-Quality Feed)
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31 pages, 4210 KiB  
Article
Optimized Feeding Strategies for Biosurfactant Production from Acetate by Alcanivorax borkumensis SK2
by Tobias Karmainski, Marie K. Lipa, Sonja Kubicki, Amina Bouchenafa, Stephan Thies, Karl-Erich Jaeger, Lars M. Blank and Till Tiso
Fermentation 2024, 10(5), 257; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050257 - 14 May 2024
Viewed by 603
Abstract
Biosurfactants are much-discussed alternatives to petro- and oleochemical surfactants. Alcanivorax borkumensis, a marine, Gram-negative γ-proteobacterium, produces a glycine-glucolipid biosurfactant from hydrocarbons, pyruvate, and acetate as carbon sources. Sustainable acetate production from lignocellulose or syngas adds to its relevance for the bioeconomy. This [...] Read more.
Biosurfactants are much-discussed alternatives to petro- and oleochemical surfactants. Alcanivorax borkumensis, a marine, Gram-negative γ-proteobacterium, produces a glycine-glucolipid biosurfactant from hydrocarbons, pyruvate, and acetate as carbon sources. Sustainable acetate production from lignocellulose or syngas adds to its relevance for the bioeconomy. This study investigated nitrogen sources and carbon-to-nitrogen ratios (C/N) to optimize fed-batch fermentation for biosurfactant production using A. borkumensis with acetate as the carbon source. Urea enabled high biosurfactant production, which was confirmed in DO-based fed-batch fermentation. Varying C/N ratios led to increased glycine-glucolipid production and decreased biomass production, with improvement plateauing at a C/N ratio of 26.7 Cmol Nmol−1. pH-stat fed-batch fermentation using glacial acetic acid as the carbon source and a pH-adjusting agent doubled the biosurfactant production. Finally, bubble-free membrane aeration was used to prevent extensive foam formation observed during conventional bubble aeration. The efficient production made it possible to investigate the bioactivity of glycine-glucolipid in combination with antibiotics against various microorganisms. Our findings allow for the leverage of glycine-glucolipid biosurfactant production using acetate as a carbon source. Full article
(This article belongs to the Special Issue Production and Application of Bioactive Biosurfactants)
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17 pages, 734 KiB  
Review
Detoxification Methods of Jatropha curcas Seed Cake and Its Potential Utilization as Animal Feed
by Cândida Rita de Barros, Luís Miguel Mendes Ferreira, Irene Fraga, José Luís Mourão and Miguel António Machado Rodrigues
Fermentation 2024, 10(5), 256; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050256 - 14 May 2024
Viewed by 484
Abstract
Jatropha seed cake (JSC) derived from Jatropha curcas seeds is a by-product of biodiesel production and, due to its high protein content, has been considered as a potential animal feed ingredient. However, the presence of toxic compounds such as phorbol esters and other anti-nutritional [...] Read more.
Jatropha seed cake (JSC) derived from Jatropha curcas seeds is a by-product of biodiesel production and, due to its high protein content, has been considered as a potential animal feed ingredient. However, the presence of toxic compounds such as phorbol esters and other anti-nutritional factors limits its use in animal feeding. Several detoxification approaches have been used to tackle these constraints and this review aims to summarize the recent advances in JSC treatment aiming to enhance its potential as an animal feedstuff. The review first provides an overview of the structure and composition of phorbol esters and other anti-nutritional compounds, discussing its toxic effects on different animal species. It then explores several detoxification methodologies giving special emphasis to its effects on the nutritional composition of JSC and on the use of the treated substrate as a feed ingredient in fish, poultry, pigs, and ruminants, highlighting their growth performance, nutrient utilization, and animal health issues. Overall, the review concludes that these treatments hold great potential for the detoxification and utilization of JSC as an animal feed ingredient. However, further research is needed to optimize the treatment conditions, evaluate the economic feasibility, and assess the long-term effects of treated JSC on animal health and product quality. Full article
(This article belongs to the Special Issue Bioconversion of Agricultural Wastes into High-Nutrition Animal Feed)
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16 pages, 6308 KiB  
Article
Enhanced Oxygen Mass Transfer in Mixing Bioreactor Using Silica Microparticles
by Matheus M. Pereira, Ivus Lorenzo Oliveira Matos, Filipe Moreira Mascarenhas Cordeiro, Ana Cristina Morais da Silva, Eliane Bezerra Cavalcanti and Álvaro Silva Lima
Fermentation 2024, 10(5), 255; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050255 - 14 May 2024
Viewed by 966
Abstract
This work aimed to improve the oxygen transfer mass coefficient (kLa) in mixing reactors, first evaluating the effect of agitation and aeration and then evaluating the influence of the size and concentration of silica microparticles. Silicon dioxide synthesized via the sol-gel [...] Read more.
This work aimed to improve the oxygen transfer mass coefficient (kLa) in mixing reactors, first evaluating the effect of agitation and aeration and then evaluating the influence of the size and concentration of silica microparticles. Silicon dioxide synthesized via the sol-gel technique, commercial sand, and beach sand were characterized by particle size distribution, scanning electron microscopy, XRD, EDS, FTIR, TG/DTA, and BET. The particles presented average values of approximately 9.2, 76.9, 165.1, and 364.4 µm, with irregular surfaces and different roughness. Silica sol-gel is amorphous while beach and commercial sand have a crystalline structure consisting of silicon, oxygen, and carbon residues. Silica sol-gel presents a higher loss of mass and surface area than other silica microparticles, with a shallow mass loss and a smaller surface. Increasing aeration and agitation improves the kLa, as well as adding silica microparticles. The best kLa was found using silica microparticles with approximately 75 µm concentrations of 1.0 g L−1 (silica sol-gel) and 2.0 g L−1 (commercial and treated beach sand). All silica microparticles used in this work improve mass transfer performance in mixing bioreactors. Full article
(This article belongs to the Section Fermentation Process Design)
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15 pages, 285 KiB  
Article
Fermentation Quality and In Vitro Digestibility of Sweet Corn Processing Byproducts Silage Mixed with Millet Hull or Wheat Bran and Inoculated with a Lactic Acid Bacteria
by Meng Yu, Peng Wang, Fuhou Li, Jiarui Du, Yitong Jin, Tianyue Zhao, Qixuan Yi, Hongyu Tang and Bao Yuan
Fermentation 2024, 10(5), 254; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050254 - 13 May 2024
Viewed by 468
Abstract
The aim of the experiment was to investigate the effect of different ratios of excipient (millet hull or wheat bran) and LAB inoculation on the fermentation quality and in vitro digestibility of a mixed silage of SCPBs. The preliminary experimental results showed that [...] Read more.
The aim of the experiment was to investigate the effect of different ratios of excipient (millet hull or wheat bran) and LAB inoculation on the fermentation quality and in vitro digestibility of a mixed silage of SCPBs. The preliminary experimental results showed that inoculating with lactic acid bacteria (LAB) directly in the fresh sweet corn processing byproduct (SCPBs) silage had a higher ammonia nitrogen/total nitrogen (AN/TN) ratio and lower silage fermentation quality due to high moisture content. Subsequently, millet hull or wheat bran were mixed with SCPBs in a 7:3 (T1), 8:2 (T2), and 9:1 (T3) ratio and ensiled with LAB. Under the condition of each mixing ratio, the silage treatments were categorized into groups without any additives (control) and with LAB. Fermentation quality, in vitro digestibility, chemical composition, and energy values were determined after 45 days of silage. The pH, AN/TN, neutral detergent fiber, acid detergent fiber, and acid detergent lignin were lowest in the SCPBs and millet hull mixed silage (SMH) group under the T3 treatment, whereas they were lowest in the SCPBs and wheat bran mixed silage (SWB) group under the T2 treatment. The mean lactic acid and acetic acid values were higher in the SWB group than in the SMH group (6.92, 6.81 vs. 4.00, 4.52). Under the T3 treatment in the SMH group, AN/TN was significantly reduced with the addition of LAB (4.52 vs. 4.37, p < 0.05). The SMH group had the highest crude protein (CP) under the T3 treatment, whereas the SWB group had the highest CP under the T2 treatment. The mean CP in the SWB group was higher than that of the SMH group (18.17, 19.44 vs. 10.55, 10.55). Under the T1 treatment, in the SWB group, the addition of LAB resulted in a significant increase in in vitro crude protein digestibility (p < 0.05). The results showed that silage fermentation quality and in vitro digestibilitv55y improved with the addition of LAB. The optimum mixing ratio for the SWB group was 9:1 and 8:2 for the SMH group. Full article
(This article belongs to the Special Issue The Use of Lactobacillus in Forage Storage and Processing)
14 pages, 1763 KiB  
Article
Characterisation of Low Molecular Weight Compounds of Strawberry Tree (Arbutus unedo L.) Fruit Spirit Aged with Oak Wood
by Ofélia Anjos, Carlos A. L. Antunes, Sheila Oliveira-Alves, Sara Canas and Ilda Caldeira
Fermentation 2024, 10(5), 253; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050253 - 13 May 2024
Viewed by 581
Abstract
There is a trend towards the commercialisation of strawberry tree fruit spirit (AUS) with wood ageing, motivated by its favourable sensory characteristics. Additionally, further studies are necessary to elucidate the optimal conditions regarding ageing time and toasting level. This study evaluated the changes [...] Read more.
There is a trend towards the commercialisation of strawberry tree fruit spirit (AUS) with wood ageing, motivated by its favourable sensory characteristics. Additionally, further studies are necessary to elucidate the optimal conditions regarding ageing time and toasting level. This study evaluated the changes in colour and low molecular weight compounds (LMWC) of AUS aged for three and six months using oak wood (Quercus robur L.) with light, medium and medium plus toasting levels. For this purpose, phenolic acids (gallic, ellagic, ferulic and syringic acids), phenolic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and furanic aldehydes (furfural, 5-hydroxymethylfurfural and 5-methylfurfural) were quantified using the HPLC method. Chromatic characteristics, colour sensory analysis and total polyphenol index were also analysed. Fourier transform near-infrared spectroscopy (FT-NIR) was used to discriminate between samples. The results emphasized the favourable effect of oak wood contact on enhancing the colour and enriching AUS with low molecular weight compounds (LMWC). AUS aged in medium toasted wood exhibits high levels of total phenolic index, 5-hydroxymethylfurfural, furfural, coniferaldehyde, sinapaldehyde, sum LMWC and chromatic characteristics b* and C. Concentrations of syringaldehyde, ellagic acid, vanillin and syringic acid and a lighter colour (a* chromaticity coordinates) are higher in AUS aged with slightly more toasted wood. Nearly all analysed parameters showed an increase with ageing time. The FT-NIR technique allowed for the differentiation of aged AUS, focusing more on ageing time than on toasting level. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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17 pages, 6377 KiB  
Article
The Effects of Pigeage, Délestage, Remontage and Oxygenation Treatments Applied during Maceration on Phenolic Content, Aroma Composition and Sensory Properties of Red Teran (Vitis vinifera L.) Wine
by Marina Tomašević, Katarina Perić, Kristijan Damijanić, Mario Staver, Natka Ćurko and Karin Kovačević Ganić
Fermentation 2024, 10(5), 252; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050252 - 13 May 2024
Viewed by 642
Abstract
The aim of this study was to evaluate the effects of mechanical (pigeage, délestage and remontage) and oxygenation treatments on the phenolic and aromatic compounds and sensory characteristics of Teran wines. The experiment included a 20-day maceration period, during which the above-mentioned treatments [...] Read more.
The aim of this study was to evaluate the effects of mechanical (pigeage, délestage and remontage) and oxygenation treatments on the phenolic and aromatic compounds and sensory characteristics of Teran wines. The experiment included a 20-day maceration period, during which the above-mentioned treatments were applied, as well as the post-fermentation processes of pressing and first rack. The analysis of phenolic, chromatic and aroma compounds and the sensory characterization of the wines were used to describe the effects of the treatments investigated. After the observed maceration period, remontage resulted in wines with the highest total phenols (2682.0 ± 14.8 mg GAE/L). In contrast, délestage resulted in the lowest total phenols (2499.1 ± 17.6 mg GAE/L) and total anthocyanins (530.1 ± 2.8 mg/L) and had the strongest effects on chromatic characteristics. The post-fermentation processes (pressing, racking) showed similar trends and resulted in higher phenolic concentrations in the remontage wine, while the délestage was again characterized by lower total phenol and anthocyanin concentrations. In addition, the délestage wine contained a higher concentration of almost all analyzed esters and two higher alcohols (2-methylpropan-1-ol and 1-hexanol), while the remontage wine had the highest concentration of 2-phenylethanol and 3-methylbutyl acetate. Finally, maceration proved to be a key factor in defining the wines’ sensory characteristics, with the remontage-treated wine showing the best overall quality. Full article
(This article belongs to the Special Issue Management of Grape Phenolic Extraction in Wine Production)
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18 pages, 2503 KiB  
Review
Innovation in Cocoa Fermentation: Evidence from Patent Documents and Scientific Articles
by Luciana Lordelo Nascimento, Marizania Sena Pereira, Lorena Santos de Almeida, Larissa da Silveira Ferreira, Bruna Louise de Moura Pita, Carolina Oliveira de Souza, Camila Duarte Ferreira Ribeiro and Alini Tinoco Fricks
Fermentation 2024, 10(5), 251; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050251 - 11 May 2024
Viewed by 1085
Abstract
This review aims to analyze the technological and scientific applications regarding cocoa fermentation through a prospective study of patent documents and research articles. The Espacenet database was used as a patent research tool by searching both the IPC code “A23G1” and the terms [...] Read more.
This review aims to analyze the technological and scientific applications regarding cocoa fermentation through a prospective study of patent documents and research articles. The Espacenet database was used as a patent research tool by searching both the IPC code “A23G1” and the terms “cocoa” and “ferment*”. A total of 130 documents were found—49 were related to the subject. The Scopus database was also searched for scientific articles using the terms “cocoa” and “fermentation”. A total of 812 articles were found—517 were related to the subject. Cocoa fermentation has not yet reached technological maturity, despite the growth in patent documents and scientific research observed in the last two decades. The creation of the Cacao of Excellence Program (2009), among others, has incentivized sustainability and quality in cocoa-producing countries. Brazil, Colombia, and Indonesia are leading with scientific publications in the last 5 years, despite the lack of patents filed. The United Kingdom, France, China, Canada, and Germany, despite not being cocoa-producing countries, are the main holders of the technology. Patent documents analyzed relate to food science, biotechnology, engineering, and chemistry. Microbial biotechnology has gained attention as a key factor to produce a higher-quality cocoa bean. Saccharomyces is the most frequent genus of yeast used as a starter culture in patent documents. Some patent documents propose the addition of fruits during cocoa fermentation, but a few scientific studies have been found on the matter. Overall, technological applications and scientific studies have focused on improving cocoa quality. The cocoa market is expected to increase significantly in the next few years, representing an opportunity to develop high-quality cocoa using novel fermentation techniques. Full article
(This article belongs to the Special Issue Advances in Fermented Fruits and Vegetables)
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16 pages, 3944 KiB  
Article
High-Level Bio-Based Production of Coproporphyrin in Escherichia coli
by Bahareh Arab, Adam Westbrook, Murray Moo-Young, Yilan Liu and C. Perry Chou
Fermentation 2024, 10(5), 250; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050250 - 11 May 2024
Viewed by 596
Abstract
This study reports on the development of effective strain engineering strategies for the high-level bio-based production of coproporphyrin (CP), a porphyrin pigment compound with various applications, using Escherichia coli as a production host. Our approach involves heterologous implementation of the Shemin/C4 pathway in [...] Read more.
This study reports on the development of effective strain engineering strategies for the high-level bio-based production of coproporphyrin (CP), a porphyrin pigment compound with various applications, using Escherichia coli as a production host. Our approach involves heterologous implementation of the Shemin/C4 pathway in an E. coli host strain with an enlarged intracellular pool of succinyl-CoA. To regulate the expression of the key pathway genes, including hemA/B/D/E/Y, we employed a plasmid system comprising two operons regulated by strong trc and gracmax promoters, respectively. Using the engineered E. coli strains for bioreactor cultivation under aerobic conditions with glycerol as the carbon source, we produced up to 353 mg/L CP with minimal byproduct formation. The overproduced CP was secreted extracellularly, posing minimal physiological toxicity and impact on the producing cells. To date, targeted bio-based production of CP by E. coli has yet to be reported. In addition to the demonstration of high-level bio-based production of CP, our study underscores the importance of identifying key enzymatic reactions limiting the overall metabolite production for developing differential expression strategies for pathway modulation and even optimization. This investigation paves the way for the development of effective metabolic engineering strategies based on targeted manipulation of key enzymes to customize engineered strains for effective large-scale bio-based production. Full article
(This article belongs to the Special Issue Production and Purification of Microbial Dyes and Pigments)
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15 pages, 831 KiB  
Article
Transcriptome Analysis of Sake Yeast in Co-Culture with kuratsuki Kocuria
by Karin Kobayashi and Hiromi Nishida
Fermentation 2024, 10(5), 249; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050249 - 10 May 2024
Viewed by 737
Abstract
Kuratsuki bacteria enter the sake production process and affect the flavor and taste of sake. This study compared gene expression in the sake yeast Saccharomyces cerevisiae in co-culture with kuratsuki Kocuria to that in monoculture. Among the 5922 genes of S. cerevisiae, [...] Read more.
Kuratsuki bacteria enter the sake production process and affect the flavor and taste of sake. This study compared gene expression in the sake yeast Saccharomyces cerevisiae in co-culture with kuratsuki Kocuria to that in monoculture. Among the 5922 genes of S. cerevisiae, 71 genes were upregulated more than 2-fold, and 61 genes were downregulated less than 0.5-fold in co-culture with kuratsuki Kocuria. Among the stress-induced genes, fourteen were upregulated, and six were downregulated. Among the fourteen upregulated genes, six were induced in response to replication stress. Although the G1 cyclin gene CLN3 was upregulated by more than 2-fold, eight genes that were induced in response to meiosis and/or sporulation were also upregulated. Fourteen metabolism-related genes, for example, the glyceraldehyde-3-phosphate dehydrogenase genes TDH1, TDH2, and TDH3, were downregulated by less than 0.5-fold in co-culture with kuratsuki Kocuria. The gene expression patterns of S. cerevisiae co-cultured with kuratsuki Kocuria differed from those co-cultured with lactic acid bacteria. Therefore, S. cerevisiae responded differently to different bacterial species. This strongly suggests that kuratsuki bacteria affect gene expression in sake yeast, thereby affecting the flavor and taste of sake. Full article
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11 pages, 1710 KiB  
Article
Biohydrogen Production under Aerial Conditions by a Nitrogen-Fixing Bacterium Isolated from a Steel Signboard
by Nobuhiro Aburai, Honami Tanaka, Hana Kohira and Tinami Sekine
Fermentation 2024, 10(5), 248; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050248 - 10 May 2024
Viewed by 601
Abstract
Hydrogen gas is attractive as a clean fuel source if it can be produced efficiently without relying on fossil fuels. Biohydrogen production using photosynthetic bacteria may enable environmentally friendly hydrogen production but is currently limited by factors such as low oxygen tolerance. In [...] Read more.
Hydrogen gas is attractive as a clean fuel source if it can be produced efficiently without relying on fossil fuels. Biohydrogen production using photosynthetic bacteria may enable environmentally friendly hydrogen production but is currently limited by factors such as low oxygen tolerance. In this study, we isolate a new strain of bacteria that can produce hydrogen under aerial-phase conditions compared with those under liquid-phase conditions in a nitrogen gas or an argon gas atmosphere. Bacterial strains were cultured from scrapings taken from a steel signboard. Investigation of the hydrogen production of the strains under aerial- and liquid-phase conditions and subsequent DNA sequencing led to identification of the bacterium Cereibacter sp. KGU-NF001. Aerial-phase conditions were achieved by filter membranes with the bacterial strains and placing the membranes on medium-soaked cotton wool. The gas atmosphere affected the behavior of the isolated bacterial strains under both aerial- and liquid-phase conditions. Cereibacter sp. KGU-NF001 showed promising oxygen tolerance and was able to maintain hydrogen production of 1.33 mL/mg/d even when the atmosphere contained 12% oxygen. Our findings illustrate that biohydrogen production may be achieved by photosynthetic bacteria under oxygen-containing aerial-phase conditions, indicating a possible pathway to help lower our reliance on fossil fuels. Full article
(This article belongs to the Special Issue Microbial Culture and Isolation for the Production of Biofuels)
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17 pages, 2084 KiB  
Article
Methane Production Reduced by Lignin Derivatives in Pulping Wastewater: Inhibition of Free Hydrolase
by Jinxu Lei, Zhihong Xu, Yong Chen, Guo Yu, Zexiang Liu, Shuangfei Wang, Jian Zhang, Kelin Li and Li Xie
Fermentation 2024, 10(5), 247; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050247 - 10 May 2024
Viewed by 648
Abstract
The lignin derivatives generated during pulping might be responsible for the suboptimal performance of anaerobic reactors during the treatment of pulping wastewater. However, the exact mechanisms by which these derivatives exert influence remain unclear. This study investigated the influence of lignin derivatives, simulated [...] Read more.
The lignin derivatives generated during pulping might be responsible for the suboptimal performance of anaerobic reactors during the treatment of pulping wastewater. However, the exact mechanisms by which these derivatives exert influence remain unclear. This study investigated the influence of lignin derivatives, simulated using humic acids (HAs), in anaerobic granular sludge (AnGS). Compared to the enzymes present during floc-bonding and granule-bonding, the HAs impeded the conversion of unhydrolyzed substrates into methane and caused considerable inactivation of free enzymes. Simultaneously, the HAs suppressed agglomeration and weakened the strength of the AnGS. Furthermore, calcium ions helped maintain the integrity of the sludge structure. Therefore, the inhibition of extracellular enzymes using lignin derivatives delays the methanation of unhydrolyzed substrates, resulting in a reduced biomass within AnGS reactors owing to sludge disintegration and biomass loss. This study serves as a reference for investigating the persistent risks originating from lignin derivatives associated with using anaerobic granular-sludge bed reactors to treat pulping wastewater. Full article
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22 pages, 713 KiB  
Review
Unlocking the Potential of Mannosylerythritol Lipids: Properties and Industrial Applications
by Joana Dias de Almeida, Miguel Figueiredo Nascimento, Petar Keković, Frederico Castelo Ferreira and Nuno Torres Faria
Fermentation 2024, 10(5), 246; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050246 - 9 May 2024
Viewed by 948
Abstract
Mannosylerythritol lipids (MELs), one of the most promising biosurfactants (BS), are glycolipids produced by yeasts or fungi, which have great environmental performance and high compatibility with the human body. MELs, besides working as typical surfactants, can form diverse structures when at or above [...] Read more.
Mannosylerythritol lipids (MELs), one of the most promising biosurfactants (BS), are glycolipids produced by yeasts or fungi, which have great environmental performance and high compatibility with the human body. MELs, besides working as typical surfactants, can form diverse structures when at or above the critical aggregation concentration (CAC), reduce the surface tension of water and other solutions, and be stable over a wide range of conditions. Among others, MELs present antimicrobial, antitumor, antioxidant and anti-inflammatory activities and skin and hair repair capacity, which opens possibilities for their use in applications from cosmetics and pharmaceutics to bioremediation and agriculture. However, their market share is still low when compared to other glycolipids, due to their less developed production process and higher production cost. This review gathers information on the potential applications of MELs mentioned in the literature since 1993. Furthermore, it also explores the current strategies being developed to enhance the market presence of MELs, in parallel with the ones developed for rhamnolipids and sophorolipids. Full article
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12 pages, 3207 KiB  
Article
Mathematical Evaluation of Population Changes of Lactobacillus acidophilus and Bifidobacterium animalis ssp. lactis as Free and Encapsulated Cells in Butter
by Rakesh Kaushik, Kritika Gaba, Sanjeev Anand and Gemechis Djira
Fermentation 2024, 10(5), 245; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050245 - 7 May 2024
Viewed by 781
Abstract
Growing butter markets, domestically and globally, provide opportunities for value-added variants of butter. Adding probiotics to butter could boosts its bioactivity; however, maintaining probiotic viability during storage is a major challenge. Mathematical analysis of probiotic population changes could help improve our understanding of [...] Read more.
Growing butter markets, domestically and globally, provide opportunities for value-added variants of butter. Adding probiotics to butter could boosts its bioactivity; however, maintaining probiotic viability during storage is a major challenge. Mathematical analysis of probiotic population changes could help improve our understanding of how probiotics interact with butter and storage conditions. Two strains of probiotics in a 1:1 ratio as free cells or Whey Protein Hydrolysate–Maltodextrin (WPH-MD)-encapsulated cells, Lactobacillus acidophilus ATCC 4356 (LA5) and Bifidobacterium animalis ssp. lactis ATCC 27536 (BB12), were separately mixed into butter at 1% levels. Using analysis of covariance, a mathematical evaluation for probiotic population changes was performed by periodically determining viable counts, resulting in an adjusted R2 value of 0.98 and demonstrating a strong relationship between the dependent variable (log10 counts of probiotics) and independent variables (cell type, temperature of storage, and time of storage). After 21 days of storage, the number of free cells in butter dropped from 7.45 log10 CFU/g to 0.56 log10 CFU/g. On the other hand, it took 63 days for encapsulated cells to achieve 0.80 log10 CFU/g at the same temperature. The same trend persisted at −18 °C, indicating that the WPH-MD encapsulant had a protective effect. Full article
(This article belongs to the Special Issue High Quality Functional Food: Potential of Probiotics 2.0)
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6 pages, 2723 KiB  
Correction
Correction: Pinu et al. The Effect of Yeast Inoculation Methods on the Metabolite Composition of Sauvignon Blanc Wines. Fermentation 2023, 9, 759
by Farhana R. Pinu, Lily Stuart, Taylan Topal, Abby Albright, Damian Martin and Claire Grose
Fermentation 2024, 10(5), 244; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050244 - 6 May 2024
Viewed by 434
Abstract
There was a technical error in the calculation of yeast cell concentrations from cell numbers in the original publication [...] Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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13 pages, 3178 KiB  
Article
Syntrophic Jiont of Sulfate-Reducing Bacteria and Hydrogen-Producing Acetogen Stimulated Methane Production from Waste Activated Sludge Digestion
by Haokun Wu, Aijuan Zhou, Yanqing Duan, Zhihong Liu, Zhangwei He, Wenzong Liu and Xiuping Yue
Fermentation 2024, 10(5), 243; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050243 - 3 May 2024
Viewed by 742
Abstract
Anaerobic digestion of waste-activated sludge (WAS) towards biogas recovery is constrained by the limited hydrolysis and inhibited acetogenesis steps that hinder subsequent energy recovery. This study employed Fe(VI)/S(IV) oxidation to enhance the WAS solubilization and coupled it with the syntrophic interaction of hydrogen-producing [...] Read more.
Anaerobic digestion of waste-activated sludge (WAS) towards biogas recovery is constrained by the limited hydrolysis and inhibited acetogenesis steps that hinder subsequent energy recovery. This study employed Fe(VI)/S(IV) oxidation to enhance the WAS solubilization and coupled it with the syntrophic interaction of hydrogen-producing acetogen (HPA) and sulfate-reducing bacteria (SRB) to stimulate the successive procedure towards methane production. Results showed that the dosage ratio of HPA-SRB to WAS (H-S-W) with 1:1:50 outperformed with the highest methane production potential (11.63 ± 1.87 mL CH4/(g VSS·d). Meanwhile, the efficient and sequential process from acetogenesis to methanogenesis stimulated by HPA-SRB was evidenced by a significant decrease of 30.2% in the acetate concentration. The microbial community structure further manifested the crucial role of HPA-SRB with increased abundance of Desulfobulbus (2.07%), Syntrophomonas (1.24%) and Smithella (1.63%), which stimulated acetophilic methanogen boost with Methanobacterium dominating with 77.51% in H-S-W100. Furthermore, the positive syntrophic relationships among HPA-SRB and acetophilic methanogens towards methane production were confirmed via molecular ecological network and canonical correspondence analysis. This study highlighted the syntrophic cooperation of the mixed consortia of HPA and SRB on methane production based on Fe(VI)/S(IV) pretreatment and provided the theoretical and technical basis for the potential implementation of novel methanogenesis technology for WAS treatment. Full article
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12 pages, 2915 KiB  
Article
An Assessment on the Fermentation Quality and Bacterial Community of Corn Straw Silage with Pineapple Residue
by Dengte Li, Huade Xie, Fanquan Zeng, Xianqing Luo, Lijuan Peng, Xinwen Sun, Xinfeng Wang and Chengjian Yang
Fermentation 2024, 10(5), 242; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050242 - 30 Apr 2024
Viewed by 742
Abstract
The effects of pineapple residue (PR) on fermentation quality, chemical composition, and bacterial community of corn straw (CS) silage were evaluated. CS was ensiled with 0% control group (CON), 15% (P1), 30% (P2), and 45% (P3) PR on a fresh matter (FM) basis [...] Read more.
The effects of pineapple residue (PR) on fermentation quality, chemical composition, and bacterial community of corn straw (CS) silage were evaluated. CS was ensiled with 0% control group (CON), 15% (P1), 30% (P2), and 45% (P3) PR on a fresh matter (FM) basis for 45 days. P3 had lower dry matter (DM) and crude protein (CP) contents but higher ammonia-N (NH3-N) content than the other three groups (p < 0.05). Compared with the other groups, P1 had lower a pH and higher lactic acid and acetic acid contents (p < 0.05). The lactic acid bacteria count in P1 was higher than in P2 and P3 (p < 0.05); the number of yeast in P2 was higher than in the other groups (p < 0.05). With the increasing proportion of PR addition, the relative abundance of Lactobacillus gradually increased, and the dominant genus in P3 was Acetobacter. In summary, the addition of PR can improve the quality of CS silage, and the optimum addition ratio for PR was 15% on a FM basis. Full article
(This article belongs to the Special Issue Application of Fermentation Technology in Animal Nutrition)
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14 pages, 5937 KiB  
Article
Enhancing Xylanase Production from Aspergillus tamarii Kita and Its Application in the Bioconversion of Agro-Industrial Residues into Fermentable Sugars Using Factorial Design
by Jose Carlos Santos Salgado, Paulo Ricardo Heinen, Josana Maria Messias, Lummy Maria Oliveira-Monteiro, Mariana Cereia, Carem Gledes Vargas Rechia, Alexandre Maller, Marina Kimiko Kadowaki, Richard John Ward and Maria de Lourdes Teixeira de Moraes Polizeli
Fermentation 2024, 10(5), 241; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050241 - 30 Apr 2024
Viewed by 874
Abstract
The endo-1,4-β-xylanases (EC 3.2.1.8) are the largest group of hydrolytic enzymes that degrade xylan, the major component of hemicelluloses, by catalyzing the hydrolysis of glycosidic bonds β-1,4 in this polymer, releasing xylooligosaccharides of different sizes. Xylanases have considerable potential in producing bread, animal [...] Read more.
The endo-1,4-β-xylanases (EC 3.2.1.8) are the largest group of hydrolytic enzymes that degrade xylan, the major component of hemicelluloses, by catalyzing the hydrolysis of glycosidic bonds β-1,4 in this polymer, releasing xylooligosaccharides of different sizes. Xylanases have considerable potential in producing bread, animal feed, food, beverages, xylitol, and bioethanol. The fungus Aspergillus tamarii Kita produced xylanases in Adams’ media supplemented with barley bagasse (brewer’s spent grains), a by-product from brewery industries. The culture extract exhibited two xylanase activities in the zymogram, identified by mass spectrometry as glycosyl hydrolase (GH) families 10 and 11 (GH 10 and GH 11). The central composite design (CCD) showed excellent predictive capacity for xylanase production (23.083 U mL−1). Additionally, other enzyme activities took place during the submerged fermentation. Moreover, enzymatic saccharification based on a mixture design (MD) of three different lignocellulosic residues was helpful in the production of fermentable sugars by the A. tamarii Kita crude extract. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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12 pages, 1891 KiB  
Article
Optimizing Curdlan Synthesis: Engineering Agrobacterium tumefaciens ATCC31749 for Enhanced Production Using Dextrin as a Carbon Source
by Tingting Yu, Yu Wang, Wei Wang, Yonggang Zhang, Yanmin Zhang, Hongyu Han, Yang Liu, Siduo Zhou and Xueqian Dong
Fermentation 2024, 10(5), 240; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050240 - 30 Apr 2024
Viewed by 720
Abstract
A key goal in current research on industrial curdlan production is the expansion of carbon sources for fermentation. In this study, a recombinant bacterial strain, sp-AmyAXCC, capable of fermenting and synthesizing curdlan using dextrin as a carbon source, was produced via heterologous expression [...] Read more.
A key goal in current research on industrial curdlan production is the expansion of carbon sources for fermentation. In this study, a recombinant bacterial strain, sp-AmyAXCC, capable of fermenting and synthesizing curdlan using dextrin as a carbon source, was produced via heterologous expression of IPTG-inducible α-amylase from Xanthomonas campestris NRRL B-1459 in Agrobacterium tumefaciens ATCC31749. External expression of the enzyme was confirmed by western blotting, and the expression levels of exogenous proteins during the fermentation process were monitored. Additionally, the properties of the curdlan product were characterized using attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray diffraction. The recombinant strain produced curdlan at a titer of 30.40 ± 0.14 g/L, gel strength of 703.5 ± 34.2 g/cm2, and a molecular weight of 3.58 × 106 Da, which is 33% greater than the molecular weight of native curdlan (2.69 × 106 Da). In the batch fermentation of sp-AmyAXCC with 12% dextrin as a carbon source, the titer of curdlan was 66.7 g/L with a yield of 0.56 g/g, and a productivity rate of 0.62 g/L/h at 108 h. The results of this study expand the substrate spectrum for Agrobacterium fermentation in curdlan production and provides guidance for further industrialization of curdlan production. Full article
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14 pages, 2857 KiB  
Article
Biodepolymerization of Polyamide Fibers Using Yarrowia lipolytica as Whole-Cell Biocatalyst
by Adriano Carniel, Nathália Ferreira dos Santos, Filipe Smith Buarque, Absai da Conceição Gomes, Luiz Silvino Chinelatto Junior, Luiz Alexandre Sacorague, Maria Alice Zarur Coelho and Aline M. Castro
Fermentation 2024, 10(5), 239; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050239 - 30 Apr 2024
Viewed by 952
Abstract
Polyamide is a thermoplastic polymer widely used for several applications, including cables in offshore oil and gas operations. Due to its growing annual production worldwide, this poorly biodegradable material has been a source of pollution. Given this scenario, the need has arisen to [...] Read more.
Polyamide is a thermoplastic polymer widely used for several applications, including cables in offshore oil and gas operations. Due to its growing annual production worldwide, this poorly biodegradable material has been a source of pollution. Given this scenario, the need has arisen to develop environmentally friendly techniques to degrade this waste, and biotechnology has emerged as a possible solution to mitigate this problem. This study aimed to investigate the potential of Yarrowia lipolytica to biodepolymerize polyamide fibers (PAF). Microbial cultures were grown in shaken flasks containing different concentrations of PAF (0.5 and 2 g·L−1) and in a bioreactor with and without pH adjustment. PAF mass loss was up to 16.8%, achieved after 96 h of cultivation in a bioreactor without pH adjustment. Additionally, NMR analyses revealed that the amorphous regions of PAF, which are more susceptible to depolymerization, were reduced by 6% during cultivation. These preliminary results indicate the biotechnological potential of Y. lipolytica to depolymerize PAF. Full article
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17 pages, 2415 KiB  
Article
Enhancing the Content of Hesperidin and Nobiletin in Citrus Wines through Multi-Strain Fermentation
by Shaoqing Zou, Yerui Ouyang, Linfeng Xie, Jiantao Liu, Ya Wang, Yiwen Xiao, Boliang Gao and Du Zhu
Fermentation 2024, 10(5), 238; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050238 - 29 Apr 2024
Viewed by 791
Abstract
This research investigates how different fermentation techniques using non-Saccharomyces yeast (Candida ethanolica Ce, Hanseniaspora guilliermondii Hg, Hanseniaspora thailandica Ht) and Saccharomyces cerevisiae (Sc) affect the synthesis of hesperidin, nobiletin, and other flavonoid and aromatic substances, which play a vital [...] Read more.
This research investigates how different fermentation techniques using non-Saccharomyces yeast (Candida ethanolica Ce, Hanseniaspora guilliermondii Hg, Hanseniaspora thailandica Ht) and Saccharomyces cerevisiae (Sc) affect the synthesis of hesperidin, nobiletin, and other flavonoid and aromatic substances, which play a vital role in improving the overall quality of fruit wines due to their various biological properties. The combination of Sc:(Ce.Ht)-1:100 (Ce 0.5 × 107 CFU/mL, Ht 0.5 × 107 CFU/mL, Sc 1 × 105 CFU/mL) yielded the highest hesperidin content at 4.12 ± 0.08 mg/L, followed by the Sc:(Ce.Hg)-1:1 (Ce 0.5 × 107 CFU/mL, Hg 0.5 × 107 CFU/mL, Sc 1 × 107 CFU/mL) combination at 4.08 ± 0.06 mg/L. The highest nobiletin content was achieved by the (Hg.Ht)-10-Sc (Hg 0.5 × 107 CFU/mL, Ht 0.5 × 107 CFU/mL, Sc 1 × 107 CFU/mL) combination, reaching 1.04 ± 0.05 mg/L, which was significantly higher than other multi-strain combinations. Additionally, the hesperidin content produced by the (Hg.Ht)-10-Sc combination was relatively high at 4.04 ± 0.02 mg/L, demonstrating a richness and complexity of aroma superior to that of fermentation with commercial yeast strains alone. The findings suggest that the (Hg.Ht)-10-Sc combination is the most effective multi-strain combination for increasing the levels of nobiletin and hesperidin in citrus wine, thereby enhancing the overall quality of the wine. These experimental results offer a promising approach for enhancing the quality of citrus wines and other fruit wines. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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14 pages, 2449 KiB  
Article
Anaerobic Conversion of Proteinogenic Amino Acids When Methanogenesis Is Inhibited: Carboxylic Acid Production from Single Amino Acids
by Leandro Conrado, Jacob McCoy, Leo Rabinovich, Mona Davoudimehr, Panagiota Stamatopoulou and Matthew Scarborough
Fermentation 2024, 10(5), 237; https://0-doi-org.brum.beds.ac.uk/10.3390/fermentation10050237 - 29 Apr 2024
Viewed by 998
Abstract
Proteins are an abundant biopolymer in organic waste feedstocks for biorefining. When degraded, amino acids are released, but their fate in non-methanogenic microbiomes is not well understood. The ability of a microbiome obtained from an anaerobic digester to produce volatile fatty acids from [...] Read more.
Proteins are an abundant biopolymer in organic waste feedstocks for biorefining. When degraded, amino acids are released, but their fate in non-methanogenic microbiomes is not well understood. The ability of a microbiome obtained from an anaerobic digester to produce volatile fatty acids from the twenty proteinogenic amino acids was tested using batch experiments. Batch tests were conducted using an initial concentration of each amino acid of 9000 mg COD L−1 along with 9000 mg COD L−1 acetate. Butyrate production was observed from lysine, glutamate, and serine fermentation. Lesser amounts of propionate, iso-butyrate, and iso-valerate were also observed from individual amino acids. Based on 16S rRNA gene amplicon sequencing, Anaerostignum, Intestimonas, Aminipila, and Oscillibacter all likely play a role in the conversion of amino acids to butyrate. The specific roles of other abundant taxa, including Coprothermobacter, Fervidobacterium, Desulfovibrio, and Wolinella, remain unknown, but these genera should be studied for their role in fermentation of amino acids and proteins to VFAs. Full article
(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)
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