Exploitation of microbial activities at low pH to enhance planetary health

FEMS Microbiology Reviews, Год журнала: 2023, Номер 48(1)

Опубликована: Ноя. 20, 2023

Abstract Awareness is growing that human health cannot be considered in isolation but inextricably woven with the of environment which we live. It is, however, under-recognized sustainability activities strongly relies on preserving equilibrium microbial communities living in/on/around us. Microbial metabolic are instrumental for production, functionalization, processing, and preservation food. For circular economy, metabolism would exploited to produce building blocks chemical industry, achieve effective crop protection, agri-food waste revalorization, or biofuel as well bioremediation bioaugmentation contaminated areas. Low pH undoubtedly a key physical–chemical parameter needs exploiting powerful arsenal. Deviation from optimal conditions has profound effects shaping responsible carrying out essential processes. Furthermore, novel strategies combat contaminations infections by pathogens rely microbial-derived acidic molecules suppress/inhibit their growth. Herein, present state-of-the-art knowledge impact many applied areas how this can guide us use immense arsenal more impactful exploitation Planetary Health perspective.

Язык: Английский

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Physiology of γ-aminobutyric acid production by Akkermansia muciniphila

Applied and Environmental Microbiology, Год журнала: 2023, Номер 90(1)

Опубликована: Дек. 13, 2023

ABSTRACT Gut bacteria hold the potential to produce a broad range of metabolites that can modulate human functions, including molecules with neuroactive potential. One such molecule is γ-aminobutyric acid (GABA), main inhibitory neurotransmitter central nervous system in animals. Metagenomic analyses suggest genomes many gut encode glutamate decarboxylase (GAD), enzyme catalyzes GABA production. The genome Akkermansia muciniphila , mucin specialist and next-generation probiotic from gut, predicted GAD, suggesting contributing role production gut. In this study, A. was grown batch cultures without pH control. both experiments, found as response (pH <5.5), although only when precursors, either or glutamine, were present medium. Proteomic analysis comparing precursors at 4 did not show difference GAD expression, it expressed regardless presence precursors. To further investigate function we heterologously gad gene (encoded by locus tag Amuc_0372) His Escherichia coli purified protein. Enzyme assays showed activity between 6, highest specific 5 144 ± 16 µM GABA/min/mg. Overall, our results demonstrate ability an unravel conditions under which occurs. IMPORTANCE considered be beneficial bacterium but exact mechanisms influences its host are yet fully understood. end, important identify produced consumed may contribute healthy (GABA) acidic environment, often occurs major For reason, bacterial metabolite. Our finding produces environments adds growing body understanding relationship health provides explanation on how survive stress

Язык: Английский

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Bacterial acid stress response: from cellular changes to antibiotic tolerance and phenotypic heterogeneity

Current Opinion in Microbiology, Год журнала: 2023, Номер 75, С. 102367 - 102367

Опубликована: Авг. 24, 2023

Язык: Английский

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Bacterial Electrophysiology

Annual Review of Biophysics, Год журнала: 2024, Номер 53(1), С. 487 - 510

Опубликована: Фев. 21, 2024

Bacterial ion fluxes are involved in the generation of energy, transport, and motility. As such, bacterial electrophysiology is fundamentally important for life cycle, but it often neglected consequently, by large, not understood. Arguably, two main reasons this complexity measuring relevant variables small cells with a cell envelope that contains wall fact that, unicellular organism, become intertwined nontrivial manner. To help give studies firm footing, review, we go back to basics. We look first at biophysics membrane potential, then approaches models developed mostly study neurons eukaryotic mitochondria. discuss their applicability cells. Finally, connect potential other (electro)physiological summarize methods can be used both measure influence electrophysiology.

Язык: Английский

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Identification of metabolites produced by six gut commensal Bacteroidales strains using non-targeted LC-MS/MS metabolite profiling

Microbiological Research, Год журнала: 2024, Номер 283, С. 127700 - 127700

Опубликована: Март 20, 2024

As the most abundant gram-negative bacterial order in gastrointestinal tract, Bacteroidales bacteria have been extensively studied for their contribution to various aspects of gut health. These are renowned involvement immunomodulation and remarkable capacity break down complex carbohydrates fibers. However, human microbiota is known produce many metabolites that ultimately mediate important microbe-host microbe-microbe interactions. To gain further insights into produced by commensal strains this order, we examined metabolite composition cell cultures stationary phase. Based on abundance tract relevance health disease, selected a total six from relevant genera Bacteroides, Phocaeicola, Parabacteroides, Segatella. We grew these modified Gifu anaerobic medium (mGAM) supplemented with mucin, which resembles microbiota's natural environment. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based profiling revealed 179 annotated had significantly differential abundances between control growth medium. Most them belonged classes such as amino acids derivatives, organic acids, nucleot(s)ides. Of particular interest, Segatella copri DSM 18205 (previously referred Prevotella copri) substantial quantities bioactive phenylethylamine, tyramine, tryptamine, ornithine. Parabacteroides merdae CL03T12C32 stood out due its ability cadaverine, histamine, acetylputrescine, deoxycarnitine. In addition, found accumulated considerable amounts proline-hydroxyproline, collagen-derived dipeptide. Collectively, findings offer more detailed comprehension metabolic potential strains, contributing better understanding role within microbiome disease.

Язык: Английский

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pH-dependent genotypic and phenotypic variability in Oleidesulfovibrio alaskensis G20

Applied and Environmental Microbiology, Год журнала: 2025, Номер unknown

Опубликована: Март 26, 2025

ABSTRACT Sulfate-reducing bacteria (SRB) exhibit versatile metabolic adaptability with significant flexibility influenced by pH fluctuations, which play a critical role in biogeochemical cycles. In this study, we used model SRB, Oleidesulfovibrio alaskensis G20, to determine the temporal effects of variations (pH 6, 7, and 8) on both growth dynamics gene expressions. The specific rate at 6 (0.014 h −1 ) closely matched that 7 (0.016 ), while 8 exhibited lower (0.010 ). Lactate consumption peaked (0.35 mM lactate.h declined (0.09 Significant hydrogen production was evident under acidic alkaline conditions. Gene expression studies revealed ATPases function as proton pumps, hydrogenases mediate reversible proton-to-hydrogen conversion. Sulfate energy metabolism act electron acceptors donors, amino acid synthesis regulates basic acids mitigate stress. Downregulation FtsZ suggests impaired division, correlating slightly longer lengths (~2 µm), upregulation divisome proteins efficient division processes, aligning shorter (~1.8 µm). This study will facilitate employment O. G20 extreme environments, enhancing its effectiveness optimizing bioremediation anaerobic digestion processes. IMPORTANCE essential roles global sulfur carbon cycling are for However, detailed genotypic phenotypic responses SRB varying conditions limited. addresses gap examining pH-dependent genetic adaptations revealing key mechanisms regulating hydrogenase ATPase activities, cell extracellular polymeric substance formation. These findings provide new insights into how maintains homeostasis, showcasing their ability survive environments. Furthermore, reveals characteristics directly aid engineer industrial effluent management systems, bioremediation, dissolved heavy metal recovery. By elucidating dynamic response varied research provides foundation resilience performance SRB-based paving way improved environmental applications.

Язык: Английский

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Isolation and characterization of Schleiferilactobacillus harbinensis GX0002947 from naturally fermented sour porridge and its application in cereal fermentation

Frontiers in Microbiology, Год журнала: 2025, Номер 16

Опубликована: Март 31, 2025

Sour porridge, a fermented food from the Guangxi Zhuang Autonomous Region of China, contains an abundance lactic acid bacteria and has high nutritional value. In this study, strain Schleiferilactobacillus harbinensis GX0002947 was isolated naturally sour porridge Fusui County, Chongzuo City, China. The highly effective in fermentation porridge. It found that S. showed good bile salt resistance at pH 3.5, concentration 0.3 g/100 mL, artificial gastrointestinal fluids, bacterial population density greater than 106 CFU/mL. broth culture supernatant antibacterial activity against foodborne pathogens Escherichia coli, Staphylococcus aureus, Bacillus cereus. optimum process for to consist temperature 37°C, inoculation dose 12.5%, time 96 h, resulting total protein content 397.33 μg/mL amino 629.63 μmol/mL addition, community diversity explored by high-throughput Illumina sequencing. results resulted formation unique microbial community. Metabolites were compared between analyzed LC-MS. This identified 24 differential metabolites which primarily included acids, carbohydrates, lipids, suggesting associated pathways played key role GX0002947. conclusion, study used assessed differences structure after with These findings provided theoretical basis technical support production.

Язык: Английский

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Pattern formation in E . coli through negative chemotaxis: Instability, condensation, and merging

Physical Review Research, Год журнала: 2025, Номер 7(2)

Опубликована: Апрель 28, 2025

Motile bacteria can migrate along chemical gradients in a process known as chemotaxis. When exposed to uniform environmental stress, cells coordinate their chemotactic responses form millimeter-sized condensates containing hundreds of thousands motile cells. In this study, we combined experiments with mathematical modeling based on modified Keller-Segel equations investigate the dynamics collective behavior across three distinct timescales: shortest timescale, where spatial instability emerges; an intermediate quasistationary bacterial form; and finally, longer during which neighboring accumulations coalesce. The model closely agrees experimental results, quantitatively capturing observed instability, shape mature condensates, coalescence dynamics. Specifically, found that force between decays exponentially distance due screening effects. We suggest presented here could describe more broadly stress-induced condensation mediated by Published American Physical Society 2025

Язык: Английский

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Rho-dependent termination enables cellular pH homeostasis

Journal of Bacteriology, Год журнала: 2024, Номер 206(1)

Опубликована: Янв. 3, 2024

ABSTRACT The termination factor Rho, an ATP-dependent RNA translocase, preempts pervasive transcription processes, thereby rendering genome integrity in bacteria. Here, we show that the loss of Rho function raised intracellular pH to >8.0 Escherichia coli . upregulates tryptophanase-A (TnaA), enzyme catabolizes tryptophan produce indole, pyruvate, and ammonia. We demonstrate enhanced TnaA had produced conjugate base ammonia, raising cellular Rho-dependent defective strains. On other hand, constitutively overexpressed lowered about 6.2, independent ammonia levels. Since overexpression may increase activities, decrease could result from excess H + ion production during ATP hydrolysis by overproduced Rho. Furthermore, performed vivo assays efficiency was increased at both acidic basic ranges. Given level remained unchanged, alkaline increases stimulating Rho’s catalytic activity. conducted Rho-mediated release assay a stalled elongation complex efficient pH, compared neutral or supports our observation. Whereas appeared elevating This study is first link homeostasis IMPORTANCE current shows gain alkalizes acidifies cytoplasm, respectively. In case function, upregulated, degrades tryptophan, producing alkalize cytoplasm. hypothesize overproduction deleting its autoregulatory DNA portion causing excessive ions cytoplasmic acidification. Therefore, this unravel relationship between intrinsic homeostasis. absence autoregulation, As plays critical role such connection alkalization will have far-reaching implications for bacterial physiology.

Язык: Английский

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Characteristics of a novel acid-resistant phenol-degrading bacterium Acinetobacter pittii Hly3: Adaptability, kinetics, degradation pathway and long-term performance

International Biodeterioration & Biodegradation, Год журнала: 2024, Номер 192, С. 105825 - 105825

Опубликована: Май 31, 2024

Язык: Английский

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