Unlocking the Potential of Brewers' Spent Grain: A Sustainable Model to Use Beer for Better Outcome in Chronic Kidney Disease.

The rising global incidence of chronic inflammatory diseases calls for innovative and sustainable medical solutions. Brewers' spent grain (BSG), a byproduct of beer production, presents a unique opportunity in this regard. This review explores the multifaceted health benefits of BSG, with a focus on managing chronic kidney disease (CKD). BSG is identified as a potent prebiotic with potential as a therapeutic agent in CKD. We emphasize the role of gut dysbiosis in CKD and discuss how BSG could help mitigate metabolic derangements resulting from dysbiosis and CKD. Fermentation of BSG further enhances its positive impact on gut health. Incorporating fermented BSG as a key component in preventive healthcare could promote a more sustainable and healthier future. By optimizing the use of this typically discarded byproduct, we can align proactive healthcare strategies with responsible resource management, benefiting both people and the environment.

Tandem Acidic CO2 Electrolysis Coupled with Syngas Fermentation: A Two-Stage Process for Producing Medium-Chain Fatty Acids.

The tandem application of CO2 electrolysis with syngas fermentation holds promise for achieving heightened production rates and improved product quality. However, the significant impact of syngas composition on mixed culture-based microbial chain elongation remains unclear. Additionally, effective methods for generating syngas with an adjustable composition from acidic CO2 electrolysis are currently lacking. This study successfully demonstrated the production of medium-chain fatty acids from CO2 through tandem acidic electrolysis with syngas fermentation. CO could serve as the sole energy source or as the electron donor (when cofed with acetate) for caproate generation. Furthermore, the results of gas diffusion electrode structure engineering highlighted that the use of carbon black, either alone or in combination with graphite, enabled consistent syngas generation with an adjustable composition from acidic CO2 electrolysis (pH 1). The carbon black layer significantly improved the CO selectivity, increasing from 0% to 43.5% (0.05 M K+) and further to 92.4% (0.5 M K+). This enhancement in performance was attributed to the promotion of K+ accumulation, stabilizing catalytically active sites, rather than creating a localized alkaline environment for CO2-to-CO conversion. This research contributes to the advancement of hybrid technology for sustainable CO2 reduction and chemical production.

Catabolism of phenolics from grape peel and its effects on gut microbiota during in vitro colonic fermentation.

BACKGROUND: Grape peels, the main by-products of wine processing, are rich in bioactive ingredients of phenolics, including proanthocyanidins, flavonoids and anthocyanins. Phenolics have the function of regulating intestinal microbiota and promoting intestinal health. From the perspective of the dietary nutrition of grape peel phenolics (GPP), this study was to investigate the influence of GPP on the composition and metabolism of human gut microbiota during in vitro fermentation. RESULTS: The results indicated that GPP could decrease pH and promote the production of short-chain fatty acids (SCFAs). ACE and Chao1 indices in GPP group were lower than that of the Blank group. GPP enhanced the levels of Lachnospiraceae UCG-004, Bacteroidetes, and Roseburia, but reduced the Firmicutes/Bacteroidetes ratio. KEGG enrichment pathways related to phenolic acid metabolism mainly included flavonoid, anthocyanin, flavone and flavonol biosynthesis. Gut microbiota could accelerate the release and breakdown of phenolic compounds, resulting in a decrease in the content of hesperetin-7-O-glucoside, delphinidin-3-O-glucoside, and cyanidin-3-rutinoside etc. In vitro antibacterial test found that GPP increased the diameters of the inhibition zones of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in a dose-dependent manner. CONCLUSION: The above results revealed that GPP might be a potential prebiotic-like to prevent diseases by improving gut health. This study could provide theoretical basis for potential to exploit GPP as dietary nutrition to maintain intestinal function. This article is protected by copyright. All rights reserved.

Effects of yeast culture on in vitro ruminal fermentation and microbial community of high concentrate diet in sheep.

This research aimed to investigate effects of different yeast culture (YC) levels on in vitro fermentation characteristics and bacterial and fungal community under high concentrate diet. A total of 5 groups were included in the experiment: control group without YC (CON), YC1 (0.5% YC proportion of substrate dry matter), YC2 (1%), YC3 (1.5%) and YC4 (2%). After 48 h of fermentation, the incubation fluids and residues were collected to analyze the ruminal fermentation parameters and bacterial and fungal community. Results showed that the ruminal fluid pH of YC2 and YC4 groups was higher (P < 0.05) than that of CON group. Compared with CON group, the microbial protein, propionate and butyrate concentrations and cumulative gas production at 48 h of YC2 group were significantly increased (P < 0.05), whereas an opposite trend of ammonia nitrogen and lactate was observed between two groups. Microbial analysis showed that the Chao1 and Shannon indexes of YC2 group were higher (P < 0.05) than those of CON group. Additionally, YC supplementation significantly decreased (P < 0.05) Succinivibrionaceae_UCG-001, Streptococcus bovis and Neosetophoma relative abundances. An opposite tendency of Aspergillus abundance was found between CON and YC treatments. Compared with CON group, the relative abundances of Prevotella, Succiniclasticum, Butyrivibrio and Megasphaera elsdenii were significantly increased (P < 0.05) in YC2 group, while Apiotrichum and unclassified Clostridiales relative abundances were decreased (P < 0.05). In conclusion, high concentrate substrate supplemented with appropriate YC (1%) can improve ruminal fermentation and regulate bacterial and fungal composition.

Anti-inflammatory effects of bay laurel (Laurus nobilis L.) towards the gut microbiome in dextran sodium sulfate induced colitis animal models.

Bay laurel (Laurus nobilis L.) contains active antioxidative phenolic components that are beneficial to human health. However, none was examined and reported utilizing health effects related to inflammatory bowel diseases (IBD) mainly ulcerative colitis (UC) in correlation to gut microbiota (GM). Thus, the current study aimed to investigate the impacts of bay leaves on UC albino rats targeting on the GM composition and their metabolites production (i.e., short-chain fatty acids; SCFAs) for improving the gut barrier functions. UC models were induced by supplementing 5% DSS into their drinking water. The models were then divided randomly for the diet with 1%, 2%, and 3% of bay leaves, as well as two control studies (positive and negative). Colon-to-body weight ratio was used as an indicator for the presence of edema tissue. From the collected fecal samples at 0, 24 h, and final day, the population changes of gut microbiota (Lactobacillus, Bifidobacteria, Clostridium, and sulfate-reducing bacteria) and SCFAs production were evaluated using fluorescence in situ hybridization (FISH) and gas-liquid chromatography (GC). The colon-to-body weight ratio of the rat models consuming 2% and 3% bay leaves was found to be significantly lower with better recovery of colonic function. Models consuming 3% bay leaves showed the best treatment effects on GM compositions; promoting the growth of Bifidobacteria and Lactobacillus in addition to producing high butyric acid levels. Meanwhile, the number of Clostridium and SRB was significantly reduced. Conclusively, consuming bay leaves brought significant colon health benefits other than stimulating appetite for a better taste.

The principal component analysis of key and significant features of the safety and nutritional value of Mahyaveh sauce.

The objective of present research is to evaluate the changes in the chemical, microbial, and biogenic amines in Persian fish sauce (Mahyaveh) during 40 days of fermentation. In the current survey, the parameters of salt percentage, pH, total nitrogen concentration, amino nitrogen concentration, Brix, color features, cadaverine, and histamine concentration were measured in the fish sauce. The amino nitrogen content, total protein, Brix, and salt were increased along with the progression of fermentation process. The microbial population of Mahyaveh sauce demonstrated that lactic acid bacteria (LAB), total bacterial count, and Enterobacteriaceae decreased during fermentation. The population of lactic acid bacteria and the total count of bacteria were around one logarithmic cycle lower in the presence of 10% salt than under low salt conditions. Histamine and cadaverine concentrations increased to 43.49 and 42.76 mg/kg during the fermentation period, respectively. As a result, the population density of histamine-producing bacteria rose from 3.00 log CFU/mL at the beginning to 4.58 log CFU/mL at the end of process. The population density of cadaverine-producing bacteria was 3.43 and 5.24 log CFU/mL on the 20th and 40th days of fermentation, respectively. Sensory evaluation results indicated that our sample of fish sauce had an overall acceptability score of 5.1 (good). On the other hand, Principal Component Analysis (PCA) demonstrated a positive correlation between the most of chemical parameters and the fermentation period. The concentration of cadaverine and histamine has a positive association with the pH and type of bacteria producing the biogenic amines.

Modulation of gut microbiota and metabolites by Flammulina velutipes polysaccharides during in vitro human fecal fermentation: Unveiling Bacteroides as a potential primary degrader.

Flammulina velutipes, a widely cultivated species of edible fungus, exhibits diverse functional activities attributed to its polysaccharides. In this study, we employed an in vitro model to investigate the impact of F. velutipes polysaccharides (FVP) fermentation on gut microbiota, with a particular focus on Bacteroides. FVP fermentation resulted in the proliferation of microbiota associated with short-chain fatty acid (SCFA) metabolism and suppression of Escherichia-Shigella. Bacteroides emerged as potential primary degraders of FVP, with species-level analysis identifying the preference of B. thetaiotaomicron and B. intestinalis in FVP degradation. Metabolomics analysis revealed significant increases in hypoxanthine and 7-methyladenine contents, with histidine metabolism emerging as the most enriched pathway. B. nordii and B. xylanisolvens exhibited the most influence on amino acid and SCFA metabolism. Understanding the mechanisms by which gut microbiota metabolize FVP can provide valuable insights into the potential of FVP to promote intestinal health and disease prevention.

Unlocking Growth Potential in Halomonas bluephagenesis for Enhanced PHA Production with Sulfate Ions.

The mutant strain H. bluephagenesis (TDH4A1B5P) was found to produce PHA under low-salt, non-sterile conditions, but the yield was low. To improve the yield, different nitrogen sources were tested. It was discovered that urea was the most effective nitrogen source for promoting growth during the stable stage, while ammonium sulfate was used during the logarithmic stage. The growth time of H. bluephagenesis (TDH4A1B5P) and its PHA content were significantly prolonged by the presence of sulfate ions. After 64 hours in a 5-liter bioreactor supplemented with sulfate ions, the dry cell weight of H. bluephagenesis weighed 132 g/l and had a PHA content of 82%. To promote the growth and PHA accumulation of H. bluephagenesis (TDH4A1B5P), a feeding regimen supplemented with nitrogen sources and sulfate ions with ammonium sodium sulfate was established in this study. The dry cell weight was 124 g/L, and the PHA content accounted for 82.3% (w/w) of the dry cell weight, resulting in a PHA yield of 101 g/L in a 30-liter bioreactor using the optimized culture strategy. In conclusion, stimulating H. bluephagenesis (TDH4A1B5P) to produce PHA is a feasible and suitable strategy for all H. bluephagenesis.

Quality and functional properties of bread containing the addition of probiotically fermented Cicer arietinum.

This study aimed to determine the impact of supplementation with probiotically fermented chickpea (Cicer arietinum L) seeds on the quality parameters and functional characteristics of wheat bread. The addition of chickpea seeds caused significant changes in the chemical composition of the control wheat bread. The legume-supplemented products exhibited higher values of a* and b* color parameters and higher hardness after 24 h of storage than the control. The application of fermented or unfermented chickpeas contributed to an increase in total polyphenol and flavonoid contents, iron chelating capacity, and antioxidant properties of the final product. The variant containing unfermented seeds had the highest riboflavin content (29.53 ± 1.11 µg/100 g d.w.), Trolox equivalent antioxidant capacity (227.02 ± 7.29 µmol·L-1 TX/100 g d.w.), and free radical scavenging activity (71.37 ± 1.30 % DPPH inhibition). The results of this preliminary research have practical importance in the production of innovative bakery products with potential properties of functional food.

Bioprocess optimization for food-grade cellulolytic enzyme production from sorghum waste in a novel solid-state fermentation bioreactor for enhanced apple juice clarification.

Transforming global agricultural waste into eco-friendly products like industrial enzymes through bioconversion can help address sustainability challenges aligning with the United Nations' Sustainable Development Goals. Present study explored the production of high-yield food-grade cellulolytic enzymes from Trichoderma reesei MTCC 4876, using a novel media formulation with a combination of waste sorghum grass and cottonseed oil cake (3:1). Optimization of physical and environmental parameters, along with the screening and optimization of media components, led to an upscaled process in a novel 6-L solid-state fermentation (SSF)-packed bed reactor (PBR) with a substrate loading of 200 g. Saturated forced aeration proved crucial, resulting in high fungal biomass (31.15 ± 0.63 mg glucosamine/gm dry fermented substrate) and high yield cellulase (20.64 ± 0.36 FPU/g-ds) and xylanase (16,186 ± 912 IU/g-ds) production at an optimal airflow rate of 0.75 LPM. The PBR exhibited higher productivity than shake flasks for all the enzyme systems. Microfiltration and ultrafiltration of the crude cellulolytic extract achieved 94% and 71% recovery, respectively, with 13.54 FPU/mL activity in the cellulolytic enzyme concentrate. The concentrate displayed stability across wide pH and temperature ranges, with a half-life of 24.5-h at 50 °C. The cellulase concentrate, validated for food-grade safety, complies with permissible limits for potential pathogens, heavy metals, mycotoxins, and pesticide residue. It significantly improved apple juice clarity (94.37 T%) by reducing turbidity (21%) and viscosity (99%) while increasing total reducing sugar release by 63% compared with untreated juice. The study also highlighted the potential use of lignin-rich fermented end residue for fuel pellets within permissible SOx emission limits, offering sustainable biorefinery prospects. Utilizing agro wastes in a controlled bioreactor environment underscores the potential for efficient large-scale cellulase production, enabling integration into food-grade applications and presenting economic benefits to fruit juice industries.

Fermentation enrichment, structural characterization and immunostimulatory effects of ß-glucan from Quinoa.

We developed an efficient mixed-strain co-fermentation method to increase the yield of quinoa ß-glucan (Q+). Using a 1:1 mass ratio of highly active dry yeast and Streptococcus thermophilus, solid-to-liquid ratio of 1:12 (g/mL), inoculum size of 3.8 % (mass fraction), fermentation at 32 °C for 27 h, we achieved the highest ß-glucan yield of (11.13 ± 0.80)%, representing remarkable 100.18 % increase in yield compared to quinoa ß-glucan(Q-) extracted using hot water. The structure of Q+ and Q- were confirmed through Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopies. Q+ contained 41.66 % ß-glucan, 3.93 % protein, 2.12 % uronic acid; Q- contained 37.21 % ß-glucan, 11.49 % protein, and 1.73 % uronic acid. The average molecular weight of Q+(75.37 kDa) was lower than that of Q- (94.47 kDa). Both Q+ and Q- promote RAW264.7 cell proliferation without displaying toxicity. They stimulate RAW264.7 cells through the NF-κB and MAPK signaling pathways, primarily inducing NO and pro-inflammatory cytokines by upregulating CD40 expression. Notably, Q+ exhibited stronger immunostimulatory activity compared to Q-. In summary, the fermentation enrichment method yields higher content of quinoa ß-glucan with increased purity and stronger immunostimulatory properties. Further study of its bioimmunological activity and structure-activity relationship may contribute to the development of new immunostimulants.

Isolation and characterization of exopolysaccharides from kombucha samples of different origins.

Kombucha is prepared by fermenting sugared green or black tea with a symbiotic culture of bacteria and yeast (SCOBY). Some of the bacteria within the SCOBY are known to form exopolysaccharides (EPS) from sucrose. However, it is yet unknown whether water-soluble EPS are formed in kombucha, and if so, which specific EPS are present. Therefore, different kombucha samples were prepared by fermentation of green and black tea with SCOBYs from different manufacturers. Subsequently, the EPS were isolated and characterized by using various chromatographic methods, partial enzymatic hydrolyses and NMR spectroscopy. It was demonstrated that levans with a varying degree of branching at position O1 (4.3-7.9 %) are present, while only trace amounts of glucans were detected. Furthermore, levans isolated from kombucha had a comparably low molecular weight and the content of levan within the kombucha samples varied from 33 to 562 mg levan/L kombucha. Therefore, our study demonstrated that levans are the main EPS type in kombucha and that levan amounts and structures varied when different starter cultures and ingredients were used. Furthermore, we provide a comprehensive data set on the structural variability of levans from kombucha.

A Novel Lactobacillus brevis Fermented with a Vegetable Substrate (AL0035) Counteracts TNBS-Induced Colitis by Modulating the Gut Microbiota Composition and Intestinal Barrier.

Crohn's and ulcerative colitis are common conditions associated with inflammatory bowel disease as well as intestinal flora and epithelial barrier dysfunction. A novel fermented Lactobacillus brevis (AL0035) herein assayed in a trinitro benzene sulfonic acid (TNBS)-induced colitis mice model after oral administration significantly counteracted the body weight loss and improves the disease activity index and histological injury scores. AL0035 significantly decreased the mRNA and protein expression of different pro-inflammatory cytokines (TNFalpha, IL-1beta, IL-6, IL-12, IFN-gamma) and enhanced the expression of IL-10. In addition, the probiotic promoted the expression of tight junction proteins, such as ZO-1, keeping the intestinal mucosal barrier function to attenuate colitis symptoms in mice. Markers of inflammation cascade such as myeloperoxidase (MPO) and PPAR-gamma measured in the colon were also modified by AL0035 treatment. AL0035 was also able to reduce different lymphocyte markers' infiltration in the colon (GATA-3, T-Bet, NK1.1) and monocyte chemoattractant protein-1 (MCP-1/CCL2), a key chemokine involved in the migration and infiltration of monocytes/macrophages in the immunological surveillance of tissues and inflammation. In colonic microbiota profile analysis through 16S rRNA sequencing, AL0035 increased the microbial diversity depleted by TNBS administration and the relative abundance of the Lactobacillaceae and Lachnospiraceae families, whereas it decreased the abundance of Proteobacteria. Altogether, these data indicated that AL0035 could lower the severity of colitis induced by TNBS by regulating inflammatory cytokines, increasing the expression of tight junction proteins and modulating intestinal microbiota, thus preventing tissue damage induced by colitis.

The effects of fermentation time on sourdough bread: An analysis of texture profile, starch digestion rate, and protein hydrolysis rate.

To ensure the best quality bread, it is important to consider the speed of digestion of starch and proteins, as well as how time fermentation and storage time influence the rate of starch digestion and the texture of the bread. This study compared the effect of fermentation time and days of storage on the texture, physicochemical, protein and starch digestibility of sourdough bread. Texture profile analysis showed that the fermentation time in recently baked sourdough bread affects hardness, chewiness, and springiness. The electrophoretic profile showed a decrease in band thickness with increase in fermentation time, consistent with a higher percentage of protein digestion. While fermentation time did not significantly affect rapidly digestible starch (RDS) and slowly digestible starch (SDS), storage time resulted in a decrease in RDS and an increase in SDS. Sourdough breads had higher levels of resistant starch (RS). The digestibility characteristics of protein and starch, as well as texture properties, are significantly influenced by fermentation and storage time. The evidence suggests that sourdough bread has the potential to improve the digestion of protein and to effectively regulate the glycemic response, which is due to its higher levels of SDS and RS.

Monitoring the yeasts ecology and volatiles profile throughout the spontaneous fermentation of Taggiasca cv. table olives through culture-dependent and independent methods.

Taggiasca table olives are typical of Liguria, a Northwestern Italian region, produced with a spontaneous fermentation carried out by placing the raw drupes directly into brine with a salt concentration of 8-12 % w/v. Such concentrations limit the development of unwanted microbes and favor the growth of yeasts. This process usually lasts up to 8 months. Yeasts are found throughout the entire fermentation process and they are mainly involved in the production of volatile organic compounds, which strongly impact the quality of the final product. The aim of this study was to evaluate the dynamics of autochthonous yeasts in brines and olives in a spontaneous process with no lye pre-treatment or addition of acids in the fermenting brine with 10 % NaCl (w/v) in two batches during 2021 harvest. Three hundred seventy-three yeast colonies were isolated, characterized by rep-PCR and identified by the D1/D2 region of the 26S rRNA gene sequencing. Mycobiota was also studied by 26S rRNA gene metataxonomics, while metabolome was assessed through GC-MS analysis. Traditional culture-dependent methods showed the dominance of Candida diddensiae, Wickerhamomyces anomalus, Pichia membranifaciens and Aureobasidium pullulans, with differences in species distribution between batches, sampling time and type of sample (olives/brines). Amplicon-based sequencing confirmed the dominance of W. anomalus in batch 1 throughout the entire fermentation, while Cyteromyces nyonsensis and Aureobasidium spp. were most abundant in the fermentation in batch 2. Volatilome results were analyzed and correlated to the mycobiota data, confirming differences between fermentation stages. Given the high appreciation for this traditional food, this study helps elucidate the mycobiota associated to Taggiasca cv. table olives and its relationship with the quality of the final product.

Ammonia-dependent reducing power redistribution for purple phototrophic bacteria culture-based biohydrogen production.

The global energy crisis has intensified the search for sustainable and clean alternatives, with biohydrogen emerging as a promising solution to address environmental challenges. Leveraging photo fermentation (PF) process, purple phototrophic bacteria (PPB) can harness reducing power derived from organic substrates to facilitate hydrogen production. However, existing studies report much lower H2 yields than theoretical value when using acetate as carbon source and ammonia as nitrogen source, primarily attributed to the widely employed pulse-feeding mode which suffers from ammonia inhibition effect on nitrogenase. To address this issue, a continuous feeding mode was applied to avoid ammonia accumulation in this study. On the other hand, other pathways like carbon fixation and polyhydroxyalkanoate (PHA) formation could compete reducing power with H2 production. However, the reducing power allocation under continuous feeding mode is not yet clear. In this study, the reducing power allocation and hydrogen production performance were evaluated under various ammonia loading, using acetate as carbon source and infrared LED at around 50 W·m-2 as light source. The results show that (a) The absence of ammonia resulted in the best performance for hydrogen production, with 44 % of the reducing power distributed to H2 and the highest H2 volumetric productivity, while the allocation of reducing power to hydrogen production stopped when ammonia loading was above 7.6 mg NH4-N·L-1·d-1; (b) when PPB required to eliminate reducing power under ammonia limited conditions, PHA production was the preferred pathway followed by the hydrogen production pathway, but once PHA accumulation reached saturation, hydrogen generation pathway dominated; (c) under ammonia limited conditions, the TCA cycle was more activated rendering higher NADH (i.e. reducing power) production compared with that under ammonia sufficient conditions which was verified by metagenomics analysis, and all the hydrogen production, PHA accumulation and carbon fixation pathways were highly active to dissipate reducing power. This work provides the insight of reducing power distribution and PPB biohydrogen production variated by ammonia loading under continuous feeding mode.

Phenotypic and genomic characterization of Methanothermobacter wolfeii strain BSEL, a CO2-capturing archaeon with minimal nutrient requirements.

A new variant of Methanothermobacter wolfeii was isolated from an anaerobic digester using enrichment cultivation in anaerobic conditions. The new isolate was taxonomically identified via 16S rRNA gene sequencing and tagged as M. wolfeii BSEL. The whole genome of the new variant was sequenced and de novo assembled. Genomic variations between the BSEL strain and the type strain were discovered, suggesting evolutionary adaptations of the BSEL strain that conferred advantages while growing under a low concentration of nutrients. M. wolfeii BSEL displayed the highest specific growth rate ever reported for the wolfeii species (0.27 ± 0.03 h-1) using carbon dioxide (CO2) as unique carbon source and hydrogen (H2) as electron donor. M. wolfeii BSEL grew at this rate in an environment with ammonium (NH4+) as sole nitrogen source. The minerals content required to cultivate the BSEL strain was relatively low and resembled the ionic background of tap water without mineral supplements. Optimum growth rate for the new isolate was observed at 64°C and pH 8.3. In this work, it was shown that wastewater from a wastewater treatment facility can be used as a low-cost alternative medium to cultivate M. wolfeii BSEL. Continuous gas fermentation fed with a synthetic biogas mimic along with H2 in a bubble column bioreactor using M. wolfeii BSEL as biocatalyst resulted in a CO2 conversion efficiency of 97% and a final methane (CH4) titer of 98.5%v, demonstrating the ability of the new strain for upgrading biogas to renewable natural gas.IMPORTANCEAs a methanogenic archaeon, Methanothermobacter wolfeii uses CO2 as electron acceptor, producing CH4 as final product. The metabolism of M. wolfeii can be harnessed to capture CO2 from industrial emissions, besides producing a drop-in renewable biofuel to substitute fossil natural gas. If used as biocatalyst in new-generation CO2 sequestration processes, M. wolfeii has the potential to accelerate the decarbonization of the energy generation sector, which is the biggest contributor of CO2 emissions worldwide. Nonetheless, the development of CO2 sequestration archaeal-based biotechnology is still limited by an uncertainty in the requirements to cultivate methanogenic archaea and the unknown longevity of archaeal cultures. In this study, we report the adaptation, isolation, and phenotypic characterization of a novel variant of M. wolfeii, which is capable of maximum growth with minimal nutrients input. Our findings demonstrate the potential of this variant for the production of renewable natural gas, paving the way for the development of more efficient and sustainable CO2 sequestration processes.

Exploring the flavor changes in mung bean flour through lactobacillus fermentation: insights from volatile compounds and non-targeted metabolomics analysis.

BACKGROUND: Mung beans are abundant in nutrition, but their leguminous flavor limits their development. Lactic Acid Bacteria (LAB) fermentation can decrease unwanted bean flavors in legumes and enhance their flavor. This study examined the influence of Lactobacillus fermentation on the flavor characteristics of mung bean flour (MBF) using volatile compounds and non-targeted metabolomics. RESULTS: Lactobacillus plantarum LP90, Lactobacillus casei LC89, and Lactobacillus acidophilus LA85 eliminated 61.37%, 48.29%, and 43.73% of the primary bean odor aldehydes from MBF. The results of relative odor activity values (ROAV) showed that fermented mung bean flour (FMBF) included volatile chemicals that contributed to fruity, flowery, and milky aromas. These compounds included ethyl acetate, hexyl formate, 3-hydroxy-2-butanone, and 2,3-butanedione. The levels of amino acids with a fresh sweet flavor increased significantly by 93.89%, 49.40%, and 35.27% in LP90, LC89, and LA85, respectively. A total of 49 up-regulated and 13 down-regulated significantly differential metabolites were annotated, and 10 metabolic pathways were screened for contributing to the flavor. The correlation between important volatile compounds and non-volatile substances relies on two primary metabolic pathways: the citric acid cycle pathway and the amino acid metabolic system. CONCLUSION: The flavor of MBF was greatly enhanced by the process of Lactobacillus fermentation, with LP90 having the most notable impact. These results serve as a reference for identifying the flavor of FMBF. This article is protected by copyright. All rights reserved.

Differential responses of rumen and fecal fermentation and microbiota of Liaoning cashmere goats after 2-hydroxy-4-(methylthio) butanoic acid isopropyl ester supplementation.

The 2-hydroxy-4-(methylthio) butanoic acid isopropyl ester (HMBi), a rumen protective methionine, has been extensively studied in dairy cows and beef cattle and has been shown to regulate gastrointestinal microbiota and improve production performance. However, knowledge of the application of HMBi on cashmere goats and the simultaneous study of rumen and hindgut microbiota is still limited. In this study, HMBi supplementation increased the concentration of total serum protein, the production of microbial protein in the rumen and feces, as well as butyrate production in the feces. The results of PCoA and PERMANOVA showed no significant difference between the rumen microbiota, but there was a dramatic difference between the fecal microbiota of the two groups of Cashmere goats after the HMBi supplementation. Specifically, in the rumen, HMBi significantly increased the relative abundance of some fiber-degrading bacteria (such as Fibrobacter) compared with the CON group. In the feces, as well as a similar effect as in the rumen (increasing the relative abundance of some fiber-degrading bacteria, such as Lachnospiraceae FCS020 group and ASV32), HMBi diets also increased the proliferation of butyrate-producing bacteria (including Oscillospiraceae UCG-005 and Christensenellaceae R-7 group). Overall, these results demonstrated that HMBi could regulate the rumen and fecal microbial composition of Liaoning cashmere goats and benefit the host.

Strategies for the efficient biosynthesis of ß-carotene through microbial fermentation.

ß-Carotene is an orange fat-soluble compound, which has been widely used in fields such as food, medicine and cosmetics owing to its anticancer, antioxidant and cardiovascular disease prevention properties. Currently, natural ß-carotene is mainly extracted from plants and algae, which cannot meet the growing market demand, while chemical synthesis of ß-carotene cannot satisfy the pursuit for natural products of consumers. The ß-carotene production through microbial fermentation has become a promising alternative owing to its high efficiency and environmental friendliness. With the rapid development of synthetic biology and in-depth study on the synthesis pathway of ß-carotene, microbial fermentation has shown promising applications in the ß-carotene synthesis. Accordingly, this review aims to summarize the research progress and strategies of natural carotenoid producing strain and metabolic engineering strategies in the heterologous synthesis of ß-carotene by engineered microorganisms. Moreover, it also summarizes the adoption of inexpensive carbon sources to synthesize ß-carotene as well as proposes new strategies that can further improve the ß-carotene production.