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Antimycin A fermentation. II. Fermentation in aerated-agitated fermenters.

Fermentation characteristics, previously studied in shake flasks, were reproduced in aerated-agitated fermenters, using three strains of Streptomyces sp. which had been selected for their high antimycin A productivity in shake flasks. Fermentation in fermenters was run in three stages. The medium consisted of soy flour, glucose, ammonium sulfate and calcium carbonate; initial pH was 7.2 approximately 7.5, and temperature 25 degrees C. The course of fermentation was then modified to encourage maximal growth and eliminate the intermediate lag period observed in shake flasks. Useful corrections included continuous addition of soybean oil at 1.25 %/day and maintenance of pH at 6 by addition of ammonium hydroxide on demand. The ammonium hydroxide added also served as a rapidly utilized nitrogen source and could not be replace by NaOH or KOH. Under optimal conditions antimycin A was produced at constant rate from the second to the sixth day, when maximum yields of more than 9 g/liter were attained. A procedure for antimycin A extraction is described.

Antimycin A

Integrated electronic nose, GC-MS, and metagenomic analyses reveal volatile flavor and microbial community differences in heap-fermented grains of Jiangxiangxing Baijiu across different fermentation degrees.

The fermentation degree of heap-fermented grains in Jiangxiangxing Baijiu production is a critical factor influencing base Baijiu quality. However, conventional assessment methods largely rely on empirical experience and therefore suffer from limited objectivity and accuracy. In this study, integrated volatile profiling and metagenomic approaches were employed to investigate volatile characteristics and microbial functional potential differentiation in fermented grains with different fermentation degrees (under-fermented, normally fermented, and over-fermented). Significant differences in physicochemical properties were observed among fermentation degrees, particularly in acidity and reducing sugar content. Electronic nose analysis revealed distinct sensor response patterns among different fermentation degrees, indicating differences in overall volatile odor fingerprint patterns. A total of 81 volatile compounds were identified by HS-SPME-GC-MS, with aldehydes, ketones, and pyrazines showing pronounced variations among fermentation degrees, and acetaldehyde exhibiting strong discriminatory potential. LEfSe analysis identified 18 microbial taxa as potential biomarkers associated with different fermentation degrees, including Pichia kudriavzevii, Lentibacillus daiqui, and Acetobacter pasteurianus. Correlation analysis revealed significant positive associations between acetaldehyde levels and Acetobacter abundance. Furthermore, KEGG, CAZy, and eggNOG analyses revealed differentiated functional potentials among fermentation degrees, providing insights into the potential metabolic basis associated with flavor differentiation. Overall, these findings highlight that fermentation degree differentiation is closely associated with coordinated changes in physicochemical conditions, microbial communities, and functional potentials, providing ecological insights into flavor differentiation and theoretical support for objective fermentation degree evaluation and quality control of Jiangxiangxing Baijiu production.

Fermentation

High-fat and low-fat fermented milk and cheese intake, proteomic signatures, and risk of all-cause and cause-specific mortality.

PURPOSE: This study aimed to examine the associations between the intake of high- and low-fat fermented dairy (cheese and fermented milk), their proteomic profiles, and mortality risk. METHODS: This cohort study included 25,187 participants (mean age 57.7 years, 60.9% females). Fermented dairy intake was assessed by a modified diet history method. In a random subset of this cohort (n&#x2009;=&#x2009;4359), we constructed proteomic signatures for fermented dairy intake using 136 candidate plasma proteins. RESULTS: During 23.5 years of follow-up, 9742 participants died. High-fat cheese (>&#x2009;20% fat) intake was inversely associated with risk of all-cause mortality (HR for an increment of 20&#xa0;g/day, 0.97; 95% CI, 0.96-0.99, P&#x2009;<&#x2009;0.001) and cardiovascular disease mortality (HR, 0.96; 95% CI, 0.93-0.99, P&#x2009;=&#x2009;0.006). Low-fat cheese intake showed an inverse association with all-cause mortality (HR, 0.98; 95% CI, 0.96-1.00, P&#x2009;=&#x2009;0.047). Low-fat fermented milk intake was inversely associated with all-cause mortality (HR for an increment of 250&#xa0;g/day, 0.91; 95% CI, 0.85-0.97, P&#x2009;=&#x2009;0.006), while high-fat fermented milk (>&#x2009;2.5% fat) showed null association. A total of 42, 26, 0, and 39 proteins were identified for the signature of high-fat cheese, low-fat cheese, high-fat fermented milk, and low-fat fermented milk, respectively. Inverse associations with all-cause mortality were observed for all three signatures with identified proteins. The identified proteins were involved in biological pathways related to immune response and inflammation. CONCLUSION: Our study indicated that consuming high-fat cheese, low-fat cheese, and low-fat fermented milk was linked to survival benefits. Plasma proteins improve our understanding of the health effects of fermented dairy.

Humans

Simmondsia chinensis (jojoba) cake fermentation: A new, sustainable technology for advanced skin and scalp care ingredients.

OBJECTIVE: Simmondsia chinensis is a well-known commercially popular plant from which jojoba oil is extracted. Jojoba cake is a sustainably produced, intractable by-product of the jojoba seed oil extraction currently used principally as a fertilizer or burned as fuel. Fermentation work conducted with various microorganisms, including Lactobacillus plantarum, Saccharomyces cerevisiae and Streptococcus thermophilus, sustainably grown on aqueous jojoba cake fermented the cake, liberating jojoba-based amino acids, peptides and proteins. The ferments have been examined chemically and via in&#xa0;vitro cell and tissue studies to develop new skin and scalp care targeted ingredients. METHODS: The jojoba cake contained nutrients (proteins, sugars and lipids) that self-sustain aqueous bacterial fermentation. The ferments were examined on 3D tissue models in&#xa0;vitro via human genomic microarrays. A ferment produced by Lactobacillus plantarum was further tested in&#xa0;vitro using ELISA protein assays on skin cell cultures. A 56-day clinical study on 46 individuals examined the influence of 1.0% of the Lactobacillus ferment on collagen expression using Diffuse Reflectance Spectroscopy (DRS). RESULTS: Gene responses were measured on 244+ genes known to have skin functions. It was found that the Lactobacillus ferment showed the greatest upregulation of skin-associated genes, and three highly upregulated proteins were examined more closely in&#xa0;vitro using ELISA protein assays: collagen-1A1, protocadherin-18 and opioid growth factor receptor. Each protein was upregulated in a dose-dependent fashion. The collagen analysis by DRS demonstrated a statistically significant increase in collagen fluorescence on Day 28 and Day 56 compared to baseline and placebo cream. Further mapping of the collagen fluorescence was done on the individuals using the active formulation at Days 0, 28 and 56. CONCLUSION: Jojoba cake presents a new source of sustainably grown biomass, but the cake is not suitable for topical applications. Fermentation produces components more suitable for topical care. In&#xa0;vitro studies demonstrated upregulation of three skin proteins associated with healing skin. Further studies also employed a newly emerging spectroscopic technique to measure collagen fluorescence in the skin in&#xa0;vivo, the results supporting in&#xa0;vitro work indicating the ferment made with Lactobacillus was able to stimulate collagen synthesis in the skin.

Lactobacillus

Assessing the diversity and functional profile of the "microbial proteome" in fermented foods.

Fermented foods are staples in diets worldwide and are known for their health benefits. Microorganisms are the key to fermented food production as they convert raw substrates into digestible, nutritious, and health-promoting products. While microbes are essential for fermented food production, their contribution to the dietary protein profile of the final food product in terms of microbial biomass is largely unknown. We analyzed proteins from 17 fermented foods using metaproteomics to identify and quantify microbial and food-derived proteins. We found that microbial proteins contribute up to 11% of the total protein content in fermented foods and comprise as much as 60% of the total number of identified proteins. These microbial proteins included many for central functions in microbial cells, such as glycolysis enzymes, translation machinery, and chaperones, as well as proteins for specialized functions that are important for the ecological niches in food fermentation, such as carbohydrate degrading enzymes and proteases. Some of these microbial proteins, such as proteases, could impact gut physiology. These findings highlight the substantial contribution of microbial proteins to the nutritional and functional profile of fermented foods, which may have important implications for interactions with the gut microbiota and health outcomes.

Fermented Foods

Yeast Strain Development and Process Intensification in High-Gravity Fermentation.

High- and very-high-gravity (HG/VHG) fermentation increases substrate loading and product titers, thereby improving fermenter utilisation and potentially reducing water use and downstream processing requirements. Initially developed for brewing and fuel ethanol production, these approaches are now applied more broadly in food, beverage, and bioproduct manufacturing. This MiniReview summarises operational definitions and industrial drivers of HG/VHG fermentation and examines the associated constraints in rheology, mass and heat transfer, osmotic and ethanol stress, nutrient availability, and oxidative damage. Yeast improvement strategies are reviewed, including adaptive laboratory evolution, mutagenesis, genome shuffling, multiplex genome editing, non-conventional yeasts, and multi-omics-guided selection. Process developments such as no-cook simultaneous liquefaction, saccharification and fermentation (SLSF), enzyme formulation, nutrient management, and in situ product recovery are considered together with applications in alcoholic beverages, organic acids, microbial lipids, and other value-added products. The review also discusses coproduct valorisation and the need to integrate strain development with process design. Current evidence supports HG/VHG fermentation as a useful process-intensification platform, although performance and sustainability depend strongly on feedstock, operating conditions, product requirements, and the basis used to report fermentation outcomes.

circular bioeconomy

Bioactive macromolecules in LAB-fermented cereals: Mechanisms of formation, functional properties, and health benefits.

Cereal and pseudo-cereal based fermented food products represent a substantial segment of global diet, nutrition as well as food security. Fermentation, especially by Lactic Acid Bacteria (LAB) increases the nutritional and functional values of foods by increasing palatability, bioavailability and minimizing antinutritional factors. LAB plays a pivotal role in synthesizing bioactive peptides, vitamins, minerals and reducing anti-nutrients parallelly. This review elucidates the mechanism through which LAB revamping nutritional macromolecules, such as peptides and polysaccharides, during fermentation and their role in the development of traditional as well as modern fermented foods. Additionally, these fermented foods have been associated with several health benefits. Recent advancement in biotechnology such as genome sequencing, functional genomics, and AI-assisted bioinformatics, have significantly enhanced our understanding of the diversity of LAB, the metabolism, and adaptation mechanisms. The combination of in silico and experimental methods has enabled the development of novel food enzymes as well as highly precise fermentation processes. Together with new innovations, growing demands for quality, consistency, safety as well as health benefits point out the significance of continued research. More studies employing both conventional and modern methods are necessary to explore these food groups completely and achieve better food quality, increased nutrition, more health benefits and comprehensive socioeconomic advantages.

Bioactive macromolecules

Consumption of traditional Sardinian fermented milk promotes changes in the rat gut microbiota composition and functions.

BACKGROUND: Fermented milk products are part of the staple diet for many Mediterranean populations. Most of these traditional foods are enriched with lactobacilli and other lactic acid bacteria, as well as with metabolites resulting from lactose fermentation. Currently, there is very little scientific knowledge on how dietary supplementation with fermented milk affects the composition of the gut microbiota and its metabolic activities. RESULTS: We integrated 16&#xa0;S rRNA gene-based taxonomic profiling with metaproteomics-based functional analysis to investigate gut microbiota changes in rats exposed to an 8-week dietary supplementation with casu axedu, a traditional fermented milk produced within rural communities in Sardinia (Italy). Several microbial taxa showed a significantly increased abundance at the end of the dietary treatment, including Phascolarctobacterium, Prevotella, Blautia glucerasea, and Lactococcus lactis, while Bacteroides dorei and Helicobacter rodentium were decreased compared to the control rats. Metaproteomic analysis highlighted a striking reshaping of the Prevotella proteome in agreement with its blooming in casu axedu-fed animals, suggesting an increase of the glycolytic activity through the Embden-Meyerhof-Parnas pathway over the Entner-Doudoroff pathway. Moreover, an increased production of enzymes involved in succinate biosynthesis was observed, which in turn significantly boosted the abundance of Phascolarctobacterium and its production of propionate. Fermented milk consumption also promoted microbial synthesis of branched chain essential amino acids L-valine and L-leucine. Finally, metaproteomic data indicated a reduction of bacterial virulence factors and host inflammatory markers, suggesting that the consumption of casu axedu can have beneficial effects on the gut mucosa health. CONCLUSIONS: Our integrated multi-omics approach reveals that dietary supplementation with the traditional Sardinian fermented milk, casu axedu, induces significant shifts in the rat gut microbiota composition and function, characterized by the enrichment of beneficial taxa and metabolic pathways associated with improved gut health and reduced inflammation.

Animals

Transcriptomic shift in ethanol and amino acid metabolic genes regulated by Med15 during alcoholic fermentation.

Organisms that thrive in extreme environments provide natural experiments in evolution, revealing the genetic regulators that orchestrate complex phenotypic change. Wine yeast are specialized strains that are adapted to survive in the wine making environment while producing high concentrations of ethanol. In addition to large genomic changes that differentiate wine yeast from yeast used in other industries, single nucleotide and polyglutamine tract polymorphisms in the transcriptional regulator Med15 are associated with the fermentation efficiency and stress response phenotypes of wine yeast. In this study we investigated the transcriptional differences during wine fermentation in transgenic lab strain yeast having integrated wine yeast MED15 alleles. Compared to the unmodified lab strain (LAB or MED15 LAB ), the same strain in which the MED15 locus was replaced with a MED15 allele from yeast isolated from palm wine, the fermented sap of palm (oil, date, coconut) trees, (WY23, or MED15 WY23 ) exhibited enhanced expression of glycolytic, fermentation, and amino acid biosynthesis genes. Our experimental data confirms the importance of arginine biosynthetic genes during the fermentation process and suggests that the improvement in fermentation efficiency in strains with MED15 alleles from some wine yeast strains may be related to the role of Med15 in expression of the genes of the arginine biosynthetic pathway. The global benefit conferred by polymorphisms in a single transcriptional regulator, makes Med15 a prime target for engineering of strains devoted to various types of alcohol production.

Journal Article

Metagenomic Insights into Microbial Assembly and Key Metabolic Genes Driving Flavor Formation in Spontaneously Fermented Zhejiang Rosy Vinegar.

The spontaneous fermentation of Zhejiang rosy vinegar (ZRV) is driven by environmental microbiota, but the processes underlying its flavor formation remain poorly understood. Using metagenomic sequencing, we investigated microbial community assembly, environmental drivers, and metabolic networks during industrial-scale ZRV fermentation. Acetic acid dominated the final organic acids. Community assembly shifted toward deterministic selection with rising acidity, with a slight rebound of stochastic processes in the late stage (R2 values of 0.442 and 0.346 for bacteria and fungi, respectively). Mantel tests confirmed that environmental factors significantly regulated microbial assembly. Co-occurrence networks grew more complex, with positive interactions accounting for 85.24% (bacteria) and 90.10% (fungi) in the late stage. Key genes (ldh, gapA, pgk) from Acetobacter pasteurianus and Lactobacillus acetotolerans dominated late-stage fermentation, while genes (adhP, SDH) from Aspergillus oryzae and Saccharomyces cerevisiae supported early- and mid-stage fermentation. These findings elucidate microbiota-driven metabolic pathways in ZRV, supporting the fermentation window optimization and industrial vinegar quality standardization.

Acetic Acid

Genomic signatures of dairy adaptation in Saccharomyces cerevisiae from traditional Yaghnob goat-cheese fermentation.

The growing interest in studying Saccharomyces cerevisiae strains from previously unexplored niches is greatly expanding our understanding of this yeast's ecology and evolution. While strains involved in alcoholic fermentation are the most studied, S. cerevisiae has also been isolated from milk fermentations and their products, suggesting a potential evolutionary specialization for dairy environments. These fermentations are characterized by the predominant presence of lactose, a carbon source that S. cerevisiae cannot metabolize directly but can exploit through the enzymatic activity of co-occurring microorganisms that convert lactose into fermentable substrates, such as glucose and galactose. In this study, we analyzed S. cerevisiae strains isolated from an unexplored and remote niche: traditional goat fermented milk produced by the Yaghnob people, an ethnically and geographically partly isolated population living in the Upper Zarafshan area of the Republic of Tajikistan. Comparative analyses with published S. cerevisiae genomes positioned the Yaghnob strains at the base of the phylogenetic dairy clade. These strains revealed distinctive coding sequences and strain-specific single-nucleotide variants present in all Yaghnob strains but absent from the other 1,053 strains analyzed. Further investigation of variants in key genes involved in galactose metabolism provided insights into the genomic and protein-level evolution of Yaghnob strains, uncovering unique genomic signatures of adaptation to the dairy environment.

Saccharomyces cerevisiae

Exploring the mechanism of aroma production in fermented cherry juice by L. brevis LD1.0600 using flavomics and whole genome analysis.

This study focused on L.brevis LD1.0600 with excellent fermentation traits: it analyzed genome-wide key regulatory genes for micro-metabolites, combined with fermented cherry juice flavor metabolomics data, and used machine learning to explore correlations between gene regulation, metabolite production, and flavor formation. The SVM model screened and verified fermented cherry juice VOCs; through OAV and flavor wheel analysis, LD1.0600 emerged as the top-performing strain, with a sweet, fruity dominant aroma. Key aroma-active components (OAV&#xa0;>&#xa0;100) included 2-methoxy-4-vinylphenol, benzaldehyde, 2-methyl-butanoic acid and hexanoic acid, and 2-methoxy-4-vinylphenol and hexanoic acid elevated by LD1.0600-regulated genes (Chrom1-001884, Chrom1-000925, fabF and Chrom1-000199). At the same time, through research, a "strain screening-SVM screening of DVCs-OAV screening of key aroma components-whole genome sequencing of flavor regulatory genes" system was established. This system can not only be applied to the screen fermentation strains, but also can be extended to the application of other fermentation products.

Fermentation

Large enrichments in fatty acid 2H/1H ratios distinguish respiration from aerobic fermentation in yeast Saccharomyces cerevisiae.

Shifts in the hydrogen stable isotopic composition (2H/1H ratio) of lipids relative to water (lipid/water 2H-fractionation) at natural abundances reflect different sources of the central cellular reductant, NADPH, in bacteria. Here, we demonstrate that lipid/water 2H-fractionation (2&#x3b5;fattyacid/water) can also constrain the relative importance of key NADPH pathways in eukaryotes. We used the metabolically flexible yeast Saccharomyces cerevisiae, a microbial model for respiratory and fermentative metabolism in industry and medicine, to investigate 2&#x3b5;fattyacid/water. In chemostats, fatty acids from glycerol-respiring cells were >550&#x2030; 2H-enriched compared to those from cells aerobically fermenting sugars via overflow metabolism, a hallmark feature in cancer. Faster growth decreased 2H/1H ratios, particularly in glycerol-respiring cells by 200&#x2030;. Variations in the activities and kinetic isotope effects among NADP+-reducing enzymes indicate cytosolic NADPH supply as the primary control on 2&#x3b5;fattyacid/water. Contributions of cytosolic isocitrate dehydrogenase (cIDH) to NAPDH production drive large 2H-enrichments with substrate metabolism (cIDH is absent during fermentation but contributes up to 20 percent NAPDH during respiration) and slower growth on glycerol (11 percent more NADPH from cIDH). Shifts in NADPH demand associated with cellular lipid abundance explain smaller 2&#x3b5;fattyacid/water variations (<30&#x2030;) with growth rate during fermentation. Consistent with these results, tests of murine liver cells had 2H-enriched lipids from slower-growing, healthy respiring cells relative to fast-growing, fermenting hepatocellular carcinoma. Our findings point to the broad potential of lipid 2H/1H ratios as a passive natural tracker of eukaryotic metabolism with applications to distinguish health and disease, complementing studies that rely on complex isotope-tracer addition methods.

Saccharomyces cerevisiae

Microbial diversity, functional activities, and safety risks in fermented tea: a comprehensive review.

Microbial fermented teas are gaining global popularity due to their unique sensory profiles and health benefits. The quality and safety of these products are governed by complex microbial ecosystems that orchestrate the biotransformation of tea leaf components. This review addresses a critical paradox in the field: the same microbial activities that generate desirable bioactive metabolites, such as theabrownins and organic acids, also create ecological niches for mycotoxigenic fungi, posing significant health risks from contaminants like ochratoxin A, citrinin, and aflatoxins. While extensive research has cataloged the microbial diversity in these systems, a comprehensive framework linking processing environments to microbial community assembly, functional outcomes, and quantifiable safety risks remains elusive. This review systematically bridges this gap by synthesizing current knowledge on the microbial consortia-dominated by Aspergillus, Penicillium, Bacillus, and Lactiplantibacillus species-that drive tea fermentation. We critically analyze their functional roles in enhancing flavor, bioactivity, and potential probiotic activity while simultaneously evaluating the mechanisms of mycotoxin production and accumulation. By integrating microbial ecology, biochemistry, and food safety, we propose a forward-looking perspective focused on transitioning the industry from traditional, spontaneous fermentation to modern, controlled biotechnological processes. This approach, centered on the use of defined starter cultures, predictive modeling, and active biocontrol strategies, provides a roadmap for ensuring the consistent quality and safety of fermented tea products, ultimately unlocking their full potential as high-quality functional foods.

Tea

Salmonella Typhimurium screen identifies shifts in mixed-acid fermentation during gut colonization.

How enteric pathogens adapt their metabolism to a dynamic gut environment is not yet fully understood. To investigate how Salmonella enterica Typhimurium (S.Tm) colonizes the gut, we conducted an in&#xa0;vivo transposon mutagenesis screen in a gnotobiotic mouse model. Our data implicate mixed-acid fermentation in efficient gut-luminal growth and energy conservation throughout infection. During initial growth, the pathogen utilizes acetate fermentation and fumarate respiration. After the onset of gut inflammation, hexoses appear to become limiting, as indicated by carbohydrate analytics and the increased need for gluconeogenesis. In response, S.Tm adapts by ramping up ethanol fermentation for redox balancing and supplying the TCA cycle with &#x3b1;-ketoglutarate for additional energy. Our findings illustrate how S.Tm flexibly adapts mixed fermentation and its use of the TCA cycle to thrive in the changing gut environment. Similar metabolic wiring in other pathogenic Enterobacteriaceae may suggest a broadly conserved mechanism for gut colonization.

Animals

Viral community in Aspergillus spp. isolated from commercially available fermented dried bonito.

Katsuobushi is a traditional processed seafood product used in Japanese-style cooking, and when it is produced through fermentation by fungi, it is called karebushi. The fungi involved in katsuobushi fermentation are collectively referred to as katsuobushi molds. We previously discovered seven novel viruses from katsuobushi molds and determined their genome sequences. However, our previous explorations used only nine fungal strains available from culture collections, leaving the diversity of viruses infecting fungi involved in katsuobushi fermentation unclear. Therefore, in this study, we aimed to isolate fungi from commercially available karebushi and clarify the prevalence of viruses in the isolates. Karebushi produced by three manufacturers was obtained, and 30 fungal strains (including Aspergillus spp.) were isolated from each. Double-stranded RNA (dsRNA) fractions were prepared from the mycelia of the isolated strains. Electrophoresis suggested that a relatively high proportion of the isolates harbored dsRNA elements consistent with RNA virus infection (30-70% per manufacturer; 59% overall). Furthermore, dsRNA sequencing identified four novel viruses in isolates of Aspergillus chevalieri and Aspergillus montevidensis: a beny-like virus, a gammapartitivirus, a narnavirus, and a victorivirus, in addition to two previously reported viruses. Notably, this represents the first report of a beny-like virus in Aspergillus spp. This study provides insights into the diversity of viruses infecting fungi involved in katsuobushi fermentation.

Aspergillus

Transcriptomic shift in ethanol and amino acid metabolic genes regulated by Med15 during alcoholic fermentation.

Organisms that thrive in extreme environments provide natural experiments in evolution, revealing the genetic regulators that orchestrate complex phenotypic change. Wine yeast (WY) are specialized strains that are adapted to survive in the wine making environment while producing high concentrations of ethanol. In addition to large genomic changes that differentiate WY from yeast used in other industries, SNP and polyglutamine tract polymorphism in the transcriptional regulator Med15 are associated with the fermentation efficiency and stress response phenotypes of WY. In this study, we investigated the transcriptional differences during wine fermentation in transgenic lab strain yeast having integrated WY MED15 alleles. Compared to the unmodified lab strain (MED15 LAB), the same strain in which the MED15 locus was replaced with a MED15 allele from yeast isolated from palm wine, the fermented sap of palm (oil, date, coconut) trees (MED15 WY23), exhibited enhanced expression of amino acid biosynthesis genes as well as stress resistance and metabolic adaptation genes. Our experimental data confirm the role of arginine in efficient fermentation and suggest that certain MED15 alleles alter the expression patterns of arginine pathway genes in some cases improving carbon flux under nitrogen stress. The global benefits conferred by natural polymorphisms in a single transcriptional regulator highlight Med15 as a target for engineering of strains devoted to various types of alcohol production.

Ethanol

Integrated &#xb9;H-NMR Metabolomics and Growth Kinetics Uncover Three Distinct Metabolic Scenarios in Lactiplantibacillus pentosus P7 Fermentation of Plant-Derived Prebiotics.

Lactic acid bacteria (LAB) drive a broad range of food and biotechnological fermentations, the outcomes of which depend not only on the bacterial genotype but also on the chemical composition of the fermentation substrate. To resolve how a single strain reorganises chemically distinct plant matrices, we profiled fermentations of Lactiplantibacillus pentosus P7 (GenBank JBLMKZ000000000) on garlic, onion, and kiwifruit extracts prepared in water and 70% ethanol, using growth kinetics combined with solvent-suppressed 500-MHz proton nuclear magnetic resonance metabolomics over 48&#xa0;h, and integrated the data with whole-genome pathway annotations. Three substrate-specific metabolic scenarios emerged. On garlic, P7 grew vigorously, with the water extract exceeding the de Man-Rogosa-Sharpe reference medium at every time point (peak &#x394;OD&#x2086;&#x2080;&#x2080; of 9.38 versus 8.52 at 24&#xa0;h) and accumulating sorbose, rhamnose, and the aromatic amino acids phenylalanine and tryptophan (3.04- to 3.70-fold increases), providing first metabolic evidence consistent with the strain's four-copy aroE shikimate-dehydrogenase expansion. On onion, the lowest cell density coincided with the highest lactate output of the dataset (5.21-fold rise at 48&#xa0;h), transient 5-hydroxymethylfurfural reduction, and accumulation of acetoin and 1,3-propanediol, mapping onto a redundant set of pyridine-nucleotide-dependent oxidoreductases and a pdu-independent diol pathway. On kiwifruit, citrate accumulated 8.9-fold at 16&#xa0;h and then declined, consistent with an intact citCDEFG citrate-lyase operon paired with absence of canonical oxidative tricarboxylic acid enzymes. The optimal extraction solvent was substrate-dependent, water for garlic and ethanol for onion and kiwifruit. Overall, these results show that substrate chemistry, rather than strain identity, dictates which genome-encoded pathways P7 engages, establishing P7 as a versatile, substrate-tunable platform for the functional fermentation and biorefining of furanic-rich substrate streams. Raw NMR data and ISA-Tab metadata are available via MetaboLights with identifier MTBLS14463.

Lactiplantibacillus pentosus