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Applied and Environmental Microbiology Jun 2022The growth of sulfate-reducing bacteria (SRB) and associated hydrogen sulfide production can be problematic in a range of industries such that inhibition strategies are...
The growth of sulfate-reducing bacteria (SRB) and associated hydrogen sulfide production can be problematic in a range of industries such that inhibition strategies are needed. A range of SRB can reduce metal ions, a strategy that has been utilized for bioremediation, metal recovery, and synthesis of precious metal catalysts. In some instances, the metal remains bound to the cell surface, and the impact of this coating on bacterial cell division and metabolism has not previously been reported. In this study, Desulfovibrio desulfuricans cells (1g dry weight) enabled the reduction of up to 1500 mmol (157.5 g) palladium (Pd) ions, resulting in cells being coated in approximately 1 μm of metal. Thickly coated cells were no longer able to metabolize or divide, ultimately leading to the death of the population. Increasing Pd coating led to prolonged inhibition of sulfate reduction, which ceased completely after cells had been coated with 1200 mmol Pd gdry cells. Less Pd nanoparticle coating permitted cells to carry out sulfate reduction and divide, allowing the population to recover over time as surface-associated Pd diminished. Overcoming inhibition in this way was more rapid using lactate as the electron donor, compared to formate. When using formate as an electron donor, preferential Pd(II) reduction took place in the presence of 100 mM sulfate. The inhibition of important metabolic pathways using a biologically enabled casing in metal highlights a new mechanism for the development of microbial control strategies. Microbial reduction of sulfate to hydrogen sulfide is highly undesirable in several industrial settings. Some sulfate-reducing bacteria are also able to transform metal ions in their environment into metal phases that remain attached to their outer cell surface. This study demonstrates the remarkable extent to which Desulfovibrio desulfuricans can be coated with locally generated metal nanoparticles, with individual cells carrying more than 100 times their mass of palladium metal. Moreover, it reveals the effect of metal coating on metabolism and replication for a wide range of metal loadings, with bacteria unable to reduce sulfate to sulfide beyond a specific threshold. These findings present a foundation for a novel means of modulating the activity of sulfate-reducing bacteria.
Topics: Bacteria; Cell Division; Desulfovibrio; Desulfovibrio desulfuricans; Formates; Hydrogen Sulfide; Oxidation-Reduction; Palladium; Sulfates; Sulfides
PubMed: 35638843
DOI: 10.1128/aem.00580-22 -
PloS One 2021Methanol is often considered as a non-competitive substrate for methanogenic archaea, but an increasing number of sulfate-reducing microorganisms (SRMs) have been...
Methanol is often considered as a non-competitive substrate for methanogenic archaea, but an increasing number of sulfate-reducing microorganisms (SRMs) have been reported to be capable of respiring with methanol as an electron donor. A better understanding of the fate of methanol in natural or artificial anaerobic systems thus requires knowledge of the methanol dissimilation by SRMs. In this study, we describe the growth kinetics and sulfur isotope effects of Desulfovibrio carbinolicus, a methanol-oxidizing sulfate-reducing deltaproteobacterium, together with its genome sequence and annotation. D. carbinolicus can grow with a series of alcohols from methanol to butanol. Compared to longer-chain alcohols, however, specific growth and respiration rates decrease by several fold with methanol as an electron donor. Larger sulfur isotope fractionation accompanies slowed growth kinetics, indicating low chemical potential at terminal reductive steps of respiration. In a medium containing both ethanol and methanol, D. carbinolicus does not consume methanol even after the cessation of growth on ethanol. Among the two known methanol dissimilatory systems, the genome of D. carbinolicus contains the genes coding for alcohol dehydrogenase but lacks enzymes analogous to methanol methyltransferase. We analyzed the genomes of 52 additional species of sulfate-reducing bacteria that have been tested for methanol oxidation. There is no apparent relationship between phylogeny and methanol metabolizing capacity, but most gram-negative methanol oxidizers grow poorly, and none carry homologs for methyltransferase (mtaB). Although the amount of available data is limited, it is notable that more than half of the known gram-positive methanol oxidizers have both enzymatic systems, showing enhanced growth relative to the SRMs containing only alcohol dehydrogenase genes. Thus, physiological, genomic, and sulfur isotopic results suggest that D. carbinolicus and close relatives have the ability to metabolize methanol but likely play a limited role in methanol degradation in most natural environments.
Topics: Cell Respiration; Desulfovibrio; Genome, Bacterial; Genomics; Methanol; Phylogeny; RNA, Ribosomal, 16S; Sulfur Isotopes
PubMed: 33444327
DOI: 10.1371/journal.pone.0245069 -
Scientific Reports Jul 2017Surface nanopatterning of metals has been an effective technique for improved performance and functionalization. However, it is of great challenge to fabricate...
Surface nanopatterning of metals has been an effective technique for improved performance and functionalization. However, it is of great challenge to fabricate nanostructure on carbon steels despite their extensive use and urgent needs to maintain the performance reliability and durability. Here, we report a one-step anodization technique to nanopattern a carbon steel in 50 wt.% NaOH solution for highly effective anti-adhesion by sulphate reducing bacteria (SRB), i.e., Desulfovibrio desulfuricans subsp. desulfuricans (Beijerinck) Kluyver and van Niel. We characterize the morphology, structure, composition, and surface roughness of the nanostructured film formed on the steel as a function of anodizing potential. We quantify the surface hydrophobicity by contact angle measurements, and the SRB adhesion by fluorescent analysis. The optimal anodization potential of 2.0 V is determined for the best performance of anti-adhesion of SRB to the steel, resulting in a 23.5 times of reduction of SRB adhesion compared to bare steel. We discuss the mechanisms for the film formation on the steel during anodization, and the high-performance anti-adhesion of bacteria to nanopatterned steels. Our technique is simple, cost-effective and environment-friendly, providing a promising alternative for industry-scale surface nanopatterning of carbon steels for effective controlling of bacterial adhesion.
Topics: Bacterial Adhesion; Desulfovibrio desulfuricans; Hydrophobic and Hydrophilic Interactions; Nanotubes, Carbon; Steel; Surface Properties
PubMed: 28706204
DOI: 10.1038/s41598-017-05626-0 -
Nature Communications Feb 2023Deep sea cold seep sediments host abundant and diverse microbial populations that significantly influence biogeochemical cycles. While numerous studies have revealed...
Deep sea cold seep sediments host abundant and diverse microbial populations that significantly influence biogeochemical cycles. While numerous studies have revealed their community structure and functional capabilities, little is known about genetic heterogeneity within species. Here, we examine intraspecies diversity patterns of 39 abundant species identified in sediment layers down to 430 cm below the sea floor across six cold seep sites. These populations are grouped as aerobic methane-oxidizing bacteria, anaerobic methanotrophic archaea and sulfate-reducing bacteria. Different evolutionary trajectories are observed at the genomic level among these physiologically and phylogenetically diverse populations, with generally low rates of homologous recombination and strong purifying selection. Functional genes related to methane (pmoA and mcrA) and sulfate (dsrA) metabolisms are under strong purifying selection in most species investigated. These genes differ in evolutionary trajectories across phylogenetic clades but are functionally conserved across sites. Intrapopulation diversification of genomes and their mcrA and dsrA genes is depth-dependent and subject to different selection pressure throughout the sediment column redox zones at different sites. These results highlight the interplay between ecological processes and the evolution of key bacteria and archaea in deep sea cold seep extreme environments, shedding light on microbial adaptation in the subseafloor biosphere.
Topics: Phylogeny; Acclimatization; Archaea; Desulfovibrio; Sulfates
PubMed: 36854684
DOI: 10.1038/s41467-023-36877-3 -
Frontiers in Cellular and Infection... 2022Tight junctions (TJs) are essential components of intestinal barrier integrity and protect the epithelium against passive paracellular flux and microbial translocation....
Tight junctions (TJs) are essential components of intestinal barrier integrity and protect the epithelium against passive paracellular flux and microbial translocation. Dysfunctional TJ leads to leaky gut, a condition associated with diseases including inflammatory bowel disease (IBD). Sulfate-Reducing Bacteria (SRB) are minor residents of the gut. An increased number of , the most predominant SRB, is observed in IBD and other diseases associated with leaky gut. However, it is not known whether contributes to leaky gut. We tested the hypothesis that (DSV) may induce intestinal permeability . Snail, a transcription factor, disrupts barrier function by affecting TJ proteins such as occludin. Intestinal alkaline phosphatase (IAP), a host defense protein, protects epithelial barrier integrity. We tested whether DSV induced permeability in polarized Caco-2 cells snail and if this effect was inhibited by IAP. Barrier integrity was assessed by measuring transepithelial electric resistance (TEER) and by 4kDa FITC-Dextran flux to determine paracellular permeability. We found that DSV reduced TEER, increased FITC-flux, upregulated snail protein expression, caused nuclear translocation of snail, and disrupted occludin staining at the junctions. DSV-induced permeability effects were inhibited in cells knocked down for snail. Pre-treatment of cells with IAP inhibited DSV-induced FITC flux and snail expression and DSV-mediated disruption of occludin staining. These data show that DSV, a resident commensal bacterium, can contribute to leaky gut and that snail may serve as a novel therapeutic target to mitigate DSV-induced effects. Taken together, our study suggests a novel underlying mechanism of association of bloom with diseases with increased intestinal permeability. Our study also underscores IAP as a novel therapeutic intervention for correcting SRB-induced leaky gut inhibition of snail.
Topics: Alkaline Phosphatase; Bacteria; Caco-2 Cells; Desulfovibrio; Fluorescein-5-isothiocyanate; GPI-Linked Proteins; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Occludin; Permeability; Sulfates; Tight Junctions
PubMed: 35694541
DOI: 10.3389/fcimb.2022.882498 -
Psychopharmacology Jan 2023Patients with chronic pain frequently suffer from anxiety symptoms. It has been well established that gut microbiota is associated with the pathogenesis of pain and...
BACKGROUND
Patients with chronic pain frequently suffer from anxiety symptoms. It has been well established that gut microbiota is associated with the pathogenesis of pain and anxiety. However, it is unknown whether the gut microbiota, particularly the specific bacteria, play a role in the comorbidity of chronic pain and anxiety.
METHODS
Chronic inflammatory pain was induced in mice by a single injection of complete Freund's adjuvant (CFA). Mice were then separated into anxiety-susceptible and anxiety-resilient phenotypes by hierarchical clustering analysis of behaviors. Fecal samples were collected to perform 16S rRNA gene sequencing. Chronic diazepam intervention served as a therapeutic strategy and its effect on the composition of gut microbiota was also determined.
RESULTS
α-Diversity and β-diversity both showed significant differences among the groups. A total of 12 gut bacteria were both altered after CFA injection and reversed by chronic diazepam treatment. More importantly, the pain hypersensitivity and anxiety-like behaviors were relieved by chronic diazepam treatment. Interestingly, we also found that Desulfovibrio was increased in anxiety-resilient group compared to control and anxiety-susceptible groups.
CONCLUSION
Abnormal composition of gut microbiota plays an essential role in chronic pain as well as in anxiety. Besides, the increased level of Desulfovibrio in anxiety-resilient mice indicated its therapeutic effects on the comorbidity of pain and anxiety. Collectively, targeting gut microbiota, especially increasing the Desulfovibrio level, might be effective in the alleviation of chronic pain-anxiety comorbidity.
Topics: Mice; Animals; Chronic Pain; RNA, Ribosomal, 16S; Anxiety; Comorbidity; Diazepam; Desulfovibrio
PubMed: 36441221
DOI: 10.1007/s00213-022-06277-4 -
Water Research Aug 2021As bridge in global cycles of carbon, nitrogen, and sulfur, sulfate-reducing bacteria (SRB) play more and more important role under various environments, especially the...
As bridge in global cycles of carbon, nitrogen, and sulfur, sulfate-reducing bacteria (SRB) play more and more important role under various environments, especially the saline-alkali environments with significant increase in area caused by human activities. Sulfate reduction can be inhibited by environmental nitrate. However, how SRB cope with environmental nitrate stress in these extreme environments still remain unclear. Here, after a long-term enrichment of sediment from saline-alkali Qinghai Lake of China using anaerobic filter reactors, nitrate was added to evaluate the response of SRB. With the increase in nitrate concentrations, the inhibition on sulfate reduction was gradually observed. Interestingly, extension of hydraulic retention time can relieve the inhibition caused by high nitrate concentration. Mass balance analysis showed that nitrate reduction is prior to sulfate reduction. Further metatranscriptomic analysis shows that, genes of nitrite reductase (periplasmic cytochrome c nitrite reductase gene) and energy metabolisms (lactate dehydrogenase, formate dehydrogenase, pyruvate:ferredoxin-oxidoreductase, and fumarate reductase genes) in SRB was down-regulated, challenging the long-held opinion that up-regulation of these genes can relieve the nitrate inhibition. Most importantly, the nitrate addition activated the denitrification pathway in denitrifying bacteria (DB) via significantly up-regulating the expression of the corresponding genes (nitrite reductase, nitric oxide reductase c subunit, nitric oxide reductase activation protein and nitrous oxide reductase genes), quickly reducing the environmental nitrate and relieving the nitrate inhibition on SRB. Our findings unravel that in response to environmental nitrate stress, haloalkaliphilic SRB show dependency on DB, and expand our knowledge of microbial relationship during sulfur and nitrogen cycles.
Topics: Bacteria; China; Desulfovibrio; Humans; Nitrates; Oxidation-Reduction; Sulfates
PubMed: 34157573
DOI: 10.1016/j.watres.2021.117354 -
World Journal of Microbiology &... Feb 2024Microbiologically-influenced corrosion (MIC) is a common operational hazard to many industrial processes. The focus of this review lies on microbial corrosion in the... (Review)
Review
Microbiologically-influenced corrosion (MIC) is a common operational hazard to many industrial processes. The focus of this review lies on microbial corrosion in the maritime industry. Microbial metal attachment and colonization are the critical steps in MIC initiation. We have outlined the crucial factors influencing corrosion caused by microorganism sulfate-reducing bacteria (SRB), where its adherence on the metal surface leads to Direct Electron Transfer (DET)-MIC. This review thus aims to summarize the recent progress and the lacunae in mitigation of MIC. We further highlight the susceptibility of stainless steel grades to SRB pitting corrosion and have included recent developments in understanding the quorum sensing mechanisms in SRB, which governs the proliferation process of the microbial community. There is a paucity of literature on the utilization of anti-quorum sensing molecules against SRB, indicating that the area of study is in its nascent stage of development. Furthermore, microbial adherence to metal is significantly impacted by surface chemistry and topography. Thus, we have reviewed the application of super wettable surfaces such as superhydrophobic, superhydrophilic, and slippery liquid-infused porous surfaces as "anti-corrosion coatings" in preventing adhesion of SRB, providing a potential avenue for the development of practical and feasible solutions in the prevention of MIC. The emerging field of super wettable surfaces holds significant potential for advancing efficient and practical MIC prevention techniques.
Topics: Corrosion; Desulfovibrio; Electron Transport; Microbiota; Porosity
PubMed: 38353843
DOI: 10.1007/s11274-024-03886-3 -
ACS Chemical Biology Jul 2022Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from...
Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR. Titration with dithionite or formate leads to reduction of three [4Fe-4S] clusters, and full reduction requires Ti(III)-citrate. The redox potentials of the four [4Fe-4S] centers range between -250 and -530 mV. Two distinct W signals were detected, W and W, which differ in only the -value. This difference can be explained by small variations in the twist angle of the two pyranopterins, as determined through DFT calculations of model compounds. The redox potential of W was determined to be -370 mV when reduced by dithionite and -340 mV when reduced by formate. The crystal structure of dithionite-reduced FdhAB was determined at high resolution (1.5 Å), revealing the same structural alterations as reported for the formate-reduced structure. These results corroborate a stable six-ligand W coordination in the catalytic intermediate W state of FdhAB.
Topics: Catalysis; Desulfovibrio; Desulfovibrio vulgaris; Dithionite; Electron Spin Resonance Spectroscopy; Formate Dehydrogenases; Formates; Metals; Oxidation-Reduction
PubMed: 35766974
DOI: 10.1021/acschembio.2c00336 -
Oxygen isotope effects during microbial sulfate reduction: applications to sediment cell abundances.The ISME Journal Jun 2020The majority of anaerobic biogeochemical cycling occurs within marine sediments. To understand these processes, quantifying the distribution of active cells and gross...
The majority of anaerobic biogeochemical cycling occurs within marine sediments. To understand these processes, quantifying the distribution of active cells and gross metabolic activity is essential. We present an isotope model rooted in thermodynamics to draw quantitative links between cell-specific sulfate reduction rates and active sedimentary cell abundances. This model is calibrated using data from a series of continuous culture experiments with two strains of sulfate reducing bacteria (freshwater bacterium Desulfovibrio vulgaris strain Hildenborough, and marine bacterium Desulfovibrio alaskensis strain G-20) grown on lactate across a range of metabolic rates and ambient sulfate concentrations. We use a combination of experimental sulfate oxygen isotope data and nonlinear regression fitting tools to solve for unknown kinetic, step-specific oxygen isotope effects. This approach enables identification of key isotopic reactions within the metabolic pathway, and defines a new, calibrated framework for understanding oxygen isotope variability in sulfate. This approach is then combined with porewater sulfate/sulfide concentration data and diagenetic modeling to reproduce measured O/O in porewater sulfate. From here, we infer cell-specific sulfate reduction rates and predict abundance of active cells of sulfate reducing bacteria, the result of which is consistent with direct biological measurements.
Topics: Bacteria; Desulfovibrio; Oxidation-Reduction; Oxygen Isotopes; Sulfates; Sulfides; Sulfur Oxides
PubMed: 32152390
DOI: 10.1038/s41396-020-0618-2