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15 pages, 1102 KiB

Open AccessArticle

Recovery of Potential Starter Cultures and Probiotics from Fermented Sorghum (Ting) Slurries

by Seth Molamu Rapoo, Phumudzo Budeli and Mathoto Lydia Thaoge

Microorganisms 2023, 11(3), 715; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms11030715 - 09 Mar 2023

Cited by 1 | Viewed by 1425

Fermented foods are thought to provide a source of probiotics that promote gut health. Consequently, isolation and characterization of fermented food strains and their applications in a controlled fermentation process or as probiotics present a new facet in this area of research. Therefore, [...] Read more.

Fermented foods are thought to provide a source of probiotics that promote gut health. Consequently, isolation and characterization of fermented food strains and their applications in a controlled fermentation process or as probiotics present a new facet in this area of research. Therefore, the current study sought to identify dominant strains in sorghum-fermented foods (ting) and characterize their probiotic potential in vitro. Recovered isolates were identified as Lactobacillus helveticus, Lactobacillus amylolyticus, Lacticaseibacillus paracasei, Lacticaseibacillus paracasei subsp paracasei, Lactiplantibacillus plantarum, Levilactobacillus brevis, Loigolactobacillus coryniformis and Loigolactobacillus coryniformis subsp torquens based on the their 16S rRNA sequences. Increased biomass was noted in seven out of nine under a low pH of 3 and a high bile concentration of 2% in vitro. Bactericidal activities of isolated LABs presented varying degrees of resistance against selected pathogenic bacteria ranging between (1.57 to 41 mm), (10 to 41 mm), and (11.26 to 42 mm) for Salmonella typhimurium ATTC 14028, Staphylococcus aureus ATTC 6538 and Escherichia coli ATTC8739, respectively. Ampicillin, erythromycin, mupirocin, tetracycline and chloramphenicol were able to inhibit growth of all selected LABs. Thus, isolates recovered from ting partially satisfy the potential candidacy for probiotics by virtue of being more tolerant to acid and bile, antibacterial activity and antibiotic resistance. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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20 pages, 4303 KiB

Open AccessArticle

The Superiority of Bacillus megaterium over Escherichia coli as a Recombinant Bacterial Host for Hyaluronic Acid Production

by HebaT’Allah Nasser, Bernhard J. Eikmanns, Mahmoud M. Tolba, Mohamed El-Azizi and Khaled Abou-Aisha

Microorganisms 2022, 10(12), 2347; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms10122347 - 28 Nov 2022

Cited by 1 | Viewed by 1893

Abstract

(1) Background: Hyaluronic acid (HA) is a polyanionic mucopolysaccharide extensively used in biomedical and cosmetic industries due to its unique rheological properties. Recombinant HA production using other microbial platforms has received increasing interest to avoid potential toxin contamination associated with its production by [...] Read more.

(1) Background: Hyaluronic acid (HA) is a polyanionic mucopolysaccharide extensively used in biomedical and cosmetic industries due to its unique rheological properties. Recombinant HA production using other microbial platforms has received increasing interest to avoid potential toxin contamination associated with its production by streptococcal fermentation. In this study, the Gram-negative strains Escherichia coli (pLysY/Iq), E. coli Rosetta2, E. coli Rosetta (DE3) pLysS, E. coli Rosetta2 (DE3), E. coli Rosetta gammiB(DE3)pLysS, and the Gram-positive Bacillus megaterium (MS941) were investigated as new platforms for the heterologous production of HA. (2) Results: The HA biosynthesis gene hasA, cloned from Streptococcus equi subsp. zoopedemicus, was ligated into plasmid pMM1522 (MoBiTec), resulting in pMM1522 hasA, which was introduced into E. coli Rosetta-2(DE3) and B. megaterium (MS941). The initial HA titer by the two hosts in the LB medium was 5 mg/L and 50 mg/L, respectively. Streptococcal hasABC and hasABCDE genes were ligated into plasmid pP_T7 (MoBiTec) and different E. coli host strains were then transformed with the resulting plasmids pP_T7hasABC and pP_T7hasABCDE. For E. coli Rosetta-gamiB(DE3)pLysS transformed with pP_T7hasABC, HA production was 500 ± 11.4 mg/L in terrific broth (TB) medium. Productivity was slightly higher (585 ± 2.9 mg/L) when the same host was transformed with pP_T7 carrying the entire HA operon. We also transformed B. megaterium (MS941) protoplasts carrying T7-RNAP with pP_T7hasABC and pP_T7hasABCDE. In comparison, the former plasmid resulted in HA titers of 2116.7 ± 44 and 1988.3 ± 19.6 mg/L in LB media supplemented with 5% sucrose and A5 medium + MOPSO, respectively; the latter plasmid boosted the titer final concentration further to reach 2476.7 ± 14.5 mg/L and 2350 ± 28.8 mg/L in the two media, respectively. The molecular mass of representative HA samples ranged from 10⁵ − 10⁶ Daltons (Da), and the polydispersity index (PDI) was <2. Fourier transform infrared spectroscopy (FTIR) spectra of the HA product were identical to those obtained for commercially available standard polymers. Finally, scanning electron microscopic examination revealed the presence of extensive HA capsules in E. coli Rosetta-gamiB(DE3)pLysS, while no HA capsules were produced by B. megaterium. (3) Conclusions: Our results suggested that Gram-positive bacteria are probably superior host strains for recombinant HA production over their Gram-negative counters. The titers and the molecular weight (MW) of HA produced by B. megaterium were significantly higher than those obtained by different E. coli host strains used in this study. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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18 pages, 2969 KiB

Open AccessArticle

Enhancing Red Yeast Biomass Yield and Lipid Biosynthesis by Using Waste Nitrogen Source by Glucose Fed-Batch at Low Temperature

by Iwona Gientka, Magdalena Wirkowska-Wojdyła, Ewa Ostrowska-Ligęza, Monika Janowicz, Lidia Reczek, Alicja Synowiec and Stanisław Błażejak

Microorganisms 2022, 10(6), 1253; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms10061253 - 20 Jun 2022

Cited by 6 | Viewed by 2094

Abstract

This work reports the effect of simple feeding strategies and temperature to obtain high-cell-density cultures of Rhodotorula glutinis var. rubescens LOCKR13 maximizing the de novo lipid productivity using deproteinated potato wastewater (DPW) as a basic medium. Feeding DPW with glucose enables a high [...] Read more.

This work reports the effect of simple feeding strategies and temperature to obtain high-cell-density cultures of Rhodotorula glutinis var. rubescens LOCKR13 maximizing the de novo lipid productivity using deproteinated potato wastewater (DPW) as a basic medium. Feeding DPW with glucose enables a high yield of Rhodotorula glutinis var. rubescens LOCKR13 biomass (52 g _d.w. L⁻¹) to be obtained. The highest values of lipid accumulation (34.15%, w/w), production (14.68 g L⁻¹) and yield coefficients (Y_L/S: 0.242 g g⁻¹), and volumetric productivity (P_L: 0.1 g L⁻¹ h⁻¹) were reached by the strain in the two-stage fed-batch process at 20 °C. The lipid of yeast biomass was rich in oleic acid (^Δ9C18:1) and palmitic acid (C16:0), and the lower temperature of incubation significantly increased the MUFA (especially oleic acid) content. For the first time, a unique set of thermal analyses of the microbial oil was performed. The isotherms of the oxidation kinetics (PDSC) showed that lipids extracted from the biomass of red yeast had high oxidative stability. This feature of the yeast oil can be useful for long-shelf-life food products and can be promising for the production of biodiesel. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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11 pages, 2565 KiB

Open AccessArticle

Anti-Melanogenic and Antioxidant Effects of Cell-Free Supernatant from Lactobacillus gasseri BNR17

by Sol Lee, Han-Oh Park and Wonbeak Yoo

Microorganisms 2022, 10(4), 788; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms10040788 - 08 Apr 2022

Cited by 13 | Viewed by 2940

Abstract

In recent years, there has been considerable interest in the use of cell-free supernatant of probiotics culture for nutritional and functional applications. In this study, we investigated the effect of the cell-free supernatant from Lactobacillus gasseri BNR17 (CFS) on anti-melanogenesis and reducing oxidative [...] Read more.

In recent years, there has been considerable interest in the use of cell-free supernatant of probiotics culture for nutritional and functional applications. In this study, we investigated the effect of the cell-free supernatant from Lactobacillus gasseri BNR17 (CFS) on anti-melanogenesis and reducing oxidative stress in B16-F10 murine melanoma cells and HaCaT human keratinocytes. Treatment with CFS significantly inhibited the production of extracellular and intracellular melanin without cytotoxicity during melanogenesis induced by the α-MSH in B16-F10 cells. The CFS dramatically reduced tyrosinase activity and the melanogenesis-related gene expression. Further, it showed antioxidative effects in a dose-dependent manner in DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assays and significantly increased the mRNA levels of HO-1 and CAT in HaCaT cells. Furthermore, the CFS increased HO-1 and anti-oxidative-related gene expression during H₂O₂-induced oxidative stress in HaCaT cells. Together, this study suggests that the CFS reduces hyperpigmentation and inhibits oxidative stress, and thus can be used as a potential skincare product in the future. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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16 pages, 2055 KiB

Open AccessArticle

Transcriptome Analysis Unveils the Effects of Proline on Gene Expression in the Yeast Komagataella phaffii

by Andrey Rumyantsev, Anton Sidorin, Artemii Volkov, Ousama Al Shanaa, Elena Sambuk and Marina Padkina

Microorganisms 2022, 10(1), 67; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms10010067 - 29 Dec 2021

Cited by 5 | Viewed by 1767

Abstract

Komagataella phaffii yeast is one of the most important biocompounds producing microorganisms in modern biotechnology. Optimization of media recipes and cultivation strategies is key to successful synthesis of recombinant proteins. The complex effects of proline on gene expression in the yeast K. phaffii [...] Read more.

Komagataella phaffii yeast is one of the most important biocompounds producing microorganisms in modern biotechnology. Optimization of media recipes and cultivation strategies is key to successful synthesis of recombinant proteins. The complex effects of proline on gene expression in the yeast K. phaffii was analyzed on the transcriptome level in this work. Our analysis revealed drastic changes in gene expression when K. phaffii was grown in proline-containing media in comparison to ammonium sulphate-containing media. Around 18.9% of all protein-encoding genes were differentially expressed in the experimental conditions. Proline is catabolized by K. phaffii even in the presence of other nitrogen, carbon and energy sources. This results in the repression of genes involved in the utilization of other element sources, namely methanol. We also found that the repression of AOX1 gene promoter with proline can be partially reversed by the deletion of the KpPUT4.2 gene. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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23 pages, 4722 KiB

Open AccessArticle

Proteomics Readjustment of the Yarrowia lipolytica Yeast in Response to Increased Temperature and Alkaline Stress

by Varvara Y. Sekova, Leonid I. Kovalyov, Marina A. Kovalyova, Natalya N. Gessler, Maria A. Danilova, Elena P. Isakova and Yulia I. Deryabina

Microorganisms 2021, 9(12), 2619; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms9122619 - 18 Dec 2021

Cited by 7 | Viewed by 2662

Abstract

Yeasts cope with a wide range of environmental challenges using different adaptive mechanisms. They can prosper at extreme ambient pH and high temperatures; however, their adaptation mechanisms have not been entirely investigated. Previously, we showed the pivotal role and flexibility of the sugar [...] Read more.

Yeasts cope with a wide range of environmental challenges using different adaptive mechanisms. They can prosper at extreme ambient pH and high temperatures; however, their adaptation mechanisms have not been entirely investigated. Previously, we showed the pivotal role and flexibility of the sugar and lipid composition of Yarrowia lipolytica W 29 upon adaptation to unfavorable conditions. In this study, we showed that extreme pH provoked significant changes in the cell wall proteins expression, with an increase in both the chaperones of heat shock protein HSP60 and some other proteins with chaperone functions. The mitochondria activity changes inducing the VDAC and malate dehydrogenase played an essential role in the adaptation, as did the altered carbohydrate metabolism, promoting its shift towards the pyruvate formation rather than gluconeogenesis. The elevated temperature led to changes in the cell wall proteins and chaperones, the induced expression of the proteins involved in the cell structural organization, ribosomal proteins, and the enzymes of formaldehyde degradation. Moreover, the readjustment of the protein composition and amount under combined stress indicated the promotion of catabolic processes related to scavenging the damaged proteins and lipids. Under all of the stress conditions studied, the process of folding, stress resistance, redox adaptation, and oxidative phosphorylation were the dominant pathways. The combined chronic alkaline and heat stress (pH 9.0, 38 °C) led to cross-adaptation, which caused “switching” over the traditional metabolism to the adaptation to the most damaging stress factor, namely the increased temperature. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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Review

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15 pages, 1657 KiB

Open AccessReview

Multiple Gene Expression in Cell-Free Protein Synthesis Systems for Reconstructing Bacteriophages and Metabolic Pathways

by Anwesha Purkayastha, Kathirvel Iyappan and Taek Jin Kang

Microorganisms 2022, 10(12), 2477; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms10122477 - 15 Dec 2022

Cited by 1 | Viewed by 2929

Abstract

As a fast and reliable technology with applications in diverse biological studies, cell-free protein synthesis has become popular in recent decades. The cell-free protein synthesis system can be considered a complex chemical reaction system that is also open to exogenous manipulation, including that [...] Read more.

As a fast and reliable technology with applications in diverse biological studies, cell-free protein synthesis has become popular in recent decades. The cell-free protein synthesis system can be considered a complex chemical reaction system that is also open to exogenous manipulation, including that which could otherwise potentially harm the cell’s viability. On the other hand, since the technology depends on the cell lysates by which genetic information is transformed into active proteins, the whole system resembles the cell to some extent. These features make cell-free protein synthesis a valuable addition to synthetic biology technologies, expediting the design–build–test–learn cycle of synthetic biology routines. While the system has traditionally been used to synthesize one protein product from one gene addition, recent studies have employed multiple gene products in order to, for example, develop novel bacteriophages, viral particles, or synthetic metabolisms. Thus, we would like to review recent advancements in applying cell-free protein synthesis technology to synthetic biology, with an emphasis on multiple gene expressions. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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39 pages, 911 KiB

Open AccessReview

Legumes and Legume-Based Beverages Fermented with Lactic Acid Bacteria as a Potential Carrier of Probiotics and Prebiotics

by Patrycja Cichońska and Małgorzata Ziarno

Microorganisms 2022, 10(1), 91; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms10010091 - 31 Dec 2021

Cited by 51 | Viewed by 7212

Abstract

Fermentation is widely used in the processing of dairy, meat, and plant products. Due to the growing popularity of plant diets and the health benefits of consuming fermented products, there has been growing interest in the fermentation of plant products and the selection [...] Read more.

Fermentation is widely used in the processing of dairy, meat, and plant products. Due to the growing popularity of plant diets and the health benefits of consuming fermented products, there has been growing interest in the fermentation of plant products and the selection of microorganisms suitable for this process. The review provides a brief overview of lactic acid bacteria (LAB) and their use in fermentation of legumes and legume-based beverages. Its scope also extends to prebiotic ingredients present in legumes and legume-based beverages that can support the growth of LAB. Legumes are a suitable matrix for the production of plant-based beverages, which are the most popular products among dairy alternatives. Legumes and legume-based beverages have been successfully fermented with LAB. Legumes are a natural source of ingredients with prebiotic properties, including oligosaccharides, resistant starch, polyphenols, and isoflavones. These compounds provide a broad range of important physiological benefits, including anti-inflammatory and immune regulation, as well as anti-cancer properties and metabolic regulation. The properties of legumes make it possible to use them to create synbiotic food, which is a source of probiotics and prebiotics. Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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24 pages, 793 KiB

Open AccessReview

Lactic Acid Bacteria-Fermentable Cereal- and Pseudocereal-Based Beverages

by Małgorzata Ziarno and Patrycja Cichońska

Microorganisms 2021, 9(12), 2532; https://0-doi-org.brum.beds.ac.uk/10.3390/microorganisms9122532 - 07 Dec 2021

Cited by 25 | Viewed by 5242

Abstract

Plant beverages are becoming more popular, and fermented cereal- or pseudocereal-based beverages are increasingly used as alternatives for fermented products made from cow milk. This review aimed to describe the basic components of cereal- or pseudocereal-based beverages and determine the feasibility of fermenting [...] Read more.

Plant beverages are becoming more popular, and fermented cereal- or pseudocereal-based beverages are increasingly used as alternatives for fermented products made from cow milk. This review aimed to describe the basic components of cereal- or pseudocereal-based beverages and determine the feasibility of fermenting them with lactic acid bacteria (LAB) to obtain products with live and active LAB cells and increased dietary value. The technology used for obtaining cereal- or pseudocereal-based milk substitutes primarily involves the extraction of selected plant material, and the obtained beverages differ in their chemical composition and nutritional value (content of proteins, lipids, and carbohydrates, glycemic index, etc.) due to the chemical diversity of the cereal and pseudocereal raw materials and the operations used for their production. Beverages made from cereals or pseudocereals are an excellent matrix for the growth of LAB, and the lactic acid fermentation not only produces desirable changes in the flavor of fermented beverages and the biological availability of nutrients but also contributes to the formation of functional compounds (e.g., B vitamins). Full article

(This article belongs to the Special Issue Advances in Microbial Biosynthesis)

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