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1.
Gut Microbes ; 16(1): 2393756, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39197040

RESUMEN

Gut microbiota of centenarians has garnered significant attention in recent years, with most studies concentrating on the analysis of microbial composition. However, there is still limited knowledge regarding the consistent signatures of specific species and their biological functions, as well as the potential causal relationship between gut microbiota and longevity. To address this, we performed the fecal metagenomic analysis of eight longevous populations at the species and functional level, and employed the Mendelian randomization (MR) analysis to infer the causal associations between microbial taxa and longevity-related traits. We observed that several species including Eisenbergiella tayi, Methanobrevibacter smithii, Hungatella hathewayi, and Desulfovibrio fairfieldensis were consistently enriched in the gut microbiota of long-lived individuals compared to younger elderly and young adults across multiple cohorts. Analysis of microbial pathways and enzymes indicated that E. tayi plays a role in the protein N-glycosylation, while M. smithii is involved in the 3-dehydroquinate and chorismate biosynthesis. Furthermore, H. hathewayi makes a distinct contribution to the purine nucleobase degradation I pathway, potentially assisting the elderly in maintaining purine homeostasis. D. fairfieldensis contributes to the menaquinone (vitamin K2) biosynthesis, which may help prevent age-related diseases such as osteoporosis-induced fractures. According to MR results, Hungatella was significantly positively correlated with parental longevity, and Desulfovibrio also exhibited positive associations with lifespan and multiple traits related to parental longevity. Additionally, Alistipes and Akkermansia muciniphila were consistently enriched in the gut microbiota of the three largest cohorts of long-lived individuals, and MR analysis also suggests their potential causal relationships with longevity. Our findings reveal longevity-associated gut microbial signatures, which are informative for understanding the role of microbiota in regulating longevity and aging.


Asunto(s)
Bacterias , Heces , Microbioma Gastrointestinal , Longevidad , Humanos , Anciano de 80 o más Años , Heces/microbiología , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Femenino , Adulto , Masculino , Anciano , Adulto Joven , Metagenómica , Persona de Mediana Edad , Desulfovibrio/genética , Desulfovibrio/metabolismo
2.
Nat Metab ; 6(8): 1601-1615, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39030389

RESUMEN

Dysbiosis of the gut microbiota has been implicated in the pathogenesis of metabolic syndrome (MetS) and may impair host metabolism through harmful metabolites. Here, we show that Desulfovibrio, an intestinal symbiont enriched in patients with MetS, suppresses the production of the gut hormone glucagon-like peptide 1 (GLP-1) through the production of hydrogen sulfide (H2S) in male mice. Desulfovibrio-derived H2S is found to inhibit mitochondrial respiration and induce the unfolded protein response in intestinal L cells, thereby hindering GLP-1 secretion and gene expression. Remarkably, blocking Desulfovibrio and H2S with an over-the-counter drug, bismuth subsalicylate, improves GLP-1 production and ameliorates diet-induced metabolic disorder in male mice. Together, our study uncovers that Desulfovibrio-derived H2S compromises GLP-1 production, shedding light on the gut-relayed mechanisms by which harmful microbiota-derived metabolites impair host metabolism in MetS and suggesting new possibilities for treating MetS.


Asunto(s)
Microbioma Gastrointestinal , Péptido 1 Similar al Glucagón , Sulfuro de Hidrógeno , Animales , Sulfuro de Hidrógeno/metabolismo , Masculino , Ratones , Péptido 1 Similar al Glucagón/metabolismo , Desulfovibrio/metabolismo , Síndrome Metabólico/metabolismo , Síndrome Metabólico/microbiología , Ratones Endogámicos C57BL
3.
Sci Total Environ ; 946: 174402, 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-38960171

RESUMEN

Sulfate-reducing bacteria (SRB) are used in the remediation of mine pollution; however, the mechanism of stabilizing multiple heavy metal(loid)s by the SRB consortium under low oxygen conditions needs further study. Indigenous microflora were extracted from non-ferrous metal-contaminated soil co-inoculated with enriched SRB consortium and assembled as the HQ23 consortium. The presence of Desulfovibrio (SRB) in HQ23 was confirmed by 16S rRNA sequencing and qPCR. The effects of culture media, dissolved oxygen (DO), SO42¯, and pH on the HQ23 growth rate, and the SO42¯-reducing activity were examined. Data indicates that the HQ23 sustained SRB function under low DO conditions (3.67 ± 0.1 mg/L), but the SRB activity was inhibited at high DO content (5.75 ± 0.39 mg/L). The HQ23 can grow from pH 5 to pH 9 and can decrease mobile or bioavailable Cr, Cu, and Zn concentrations in contaminated soil samples. FTIR revealed that Cu and Cr adsorbed to similar binding sites on bacteria, likely decreasing bacterial Cu toxicity. Increased abundances of DSV (marker for Desulfovibrio) and nifH (N-fixation) genes were observed, as well as an accumulation of nitrate-N content in soils suggesting that HQ23 stimulates the biological N-fixation in soils. This study strongly supports the future application of SRB for the bioremediation of heavy metal-polluted sites.


Asunto(s)
Metales Pesados , Microbiología del Suelo , Contaminantes del Suelo , Contaminantes del Suelo/metabolismo , Metales Pesados/metabolismo , Fijación del Nitrógeno , Sulfatos/metabolismo , Suelo/química , Biodegradación Ambiental , Consorcios Microbianos , Desulfovibrio/metabolismo , ARN Ribosómico 16S
4.
Adv Microb Physiol ; 85: 145-200, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39059820

RESUMEN

The human gut flora comprises a dynamic network of bacterial species that coexist in a finely tuned equilibrium. The interaction with intestinal bacteria profoundly influences the host's development, metabolism, immunity, and overall health. Furthermore, dysbiosis, a disruption of the gut microbiota, can induce a variety of diseases, not exclusively associated with the intestinal tract. The increased consumption of animal protein, high-fat and high-sugar diets in Western countries has been implicated in the rise of chronic and inflammatory illnesses associated with dysbiosis. In particular, this diet leads to the overgrowth of sulfide-producing bacteria, known as sulfidogenic bacteria, which has been linked to inflammatory bowel diseases and colorectal cancer, among other disorders. Sulfidogenic bacteria include sulfate-reducing bacteria (Desulfovibrio spp.) and Bilophila wadsworthia among others, which convert organic and inorganic sulfur compounds to sulfide through the dissimilatory sulfite reduction pathway. At high concentrations, sulfide is cytotoxic and disrupts the integrity of the intestinal epithelium and mucus barrier, triggering inflammation. Besides producing sulfide, B. wadsworthia has revealed significant pathogenic potential, demonstrated in the ability to cause infection, adhere to intestinal cells, promote inflammation, and compromise the integrity of the colonic mucus layer. This review delves into the mechanisms by which taurine and sulfide-driven gut dysbiosis contribute to the pathogenesis of sulfidogenic bacteria, and discusses the role of these gut microbes, particularly B. wadsworthia, in human diseases.


Asunto(s)
Disbiosis , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/fisiología , Disbiosis/microbiología , Enfermedades Inflamatorias del Intestino/microbiología , Enfermedades Inflamatorias del Intestino/metabolismo , Sulfuros/metabolismo , Desulfovibrio/metabolismo , Bilophila/metabolismo , Taurina/metabolismo , Animales , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/metabolismo , Bacterias/metabolismo , Bacterias/genética
5.
J Colloid Interface Sci ; 674: 938-950, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38959739

RESUMEN

Biosynthetic metal sulfides showed great application prospects in the environmental treatment against high-valence metal pollutants. However, the efficiency of biosynthesis, agglomeration during the reaction process, and the formation of the passivation layer during the reduction process were always the important factors restricting its development. This study explored the composition of the culture medium to promote the growth of highly corrosive sulfate-reducing bacteria (SRB) and its metabolism to produce FeS nanoparticles (NPs). The results showed that reducing the carbon source (CS) and adding electron carriers in the culture medium effectively promoted the production of small, dispersed, and loose FeS NPs in cells. At pH = 7, 24 °C and 10 min reaction time, 0.1 g/L FeS NPs produced by SRB under the conditions of 10 % CS with 10 ppm cytochrome c medium could achieve 100 % removal efficiency of 1 mM hexavalent chromium (Cr(VI)). Under this condition, FeS NPs could be produced by intracellular metabolism in SRB cells, and environmental factors such as pH, metal cations, and Cl- had little effect on the removal of Cr(VI) by this FeS NPs. The surface proteins of FeS NPs significantly enhanced their antioxidant properties. After 7 days of natural environment exposure, the Cr(VI) removal efficiency of FeS NPs was only reduced by 16 % compared with the initial sample. This work provided an in-depth understanding of Cr(VI) removal by SRB biosynthesis of FeS and contributes to the widespread application of FeS in the future.


Asunto(s)
Carbono , Cromo , Cromo/metabolismo , Cromo/química , Carbono/química , Carbono/metabolismo , Desulfovibrio/metabolismo , Compuestos Ferrosos/metabolismo , Compuestos Ferrosos/química , Electrones , Propiedades de Superficie , Tamaño de la Partícula , Concentración de Iones de Hidrógeno
6.
Gut Microbes ; 16(1): 2370634, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38935546

RESUMEN

Diet is a key player in gut-liver axis. However, the effect of different dietary patterns on gut microbiota and liver functions remains unclear. Here, we used rodent standard chow and purified diet to mimic two common human dietary patterns: grain and plant-based diet and refined-food-based diet, respectively and explored their impacts on gut microbiota and liver. Gut microbiota experienced a great shift with notable increase in Desulfovibrio, gut bile acid (BA) levels elevated significantly, and liver inflammation was observed in mice fed with the purified diet. Liver inflammation and elevated gut BA levels also occurred in mice fed with the chow diet after receiving Desulfovibrio desulfuricans ATCC 29,577 (DSV). Restriction of sulfur-containing amino acids (SAAs) prevented liver injury mainly through higher hepatic antioxidant and detoxifying ability and reversed the elevated BA levels due to excess Desulfovibrio. Ex vivo fermentation of human fecal microbiota with primary BAs demonstrated that DSV enhanced production of secondary BAs. Higher concentration of both primary and secondary BAs were found in the gut of germ-free mice after receiving DSV. In conclusion, Restriction of SAAs in diet may become an effective dietary intervention to prevent liver injury associated with excess Desulfovibrio in the gut.


Asunto(s)
Desulfovibrio , Microbioma Gastrointestinal , Hígado , Ratones Endogámicos C57BL , Animales , Microbioma Gastrointestinal/efectos de los fármacos , Ratones , Hígado/metabolismo , Humanos , Desulfovibrio/metabolismo , Masculino , Ácidos y Sales Biliares/metabolismo , Aminoácidos/metabolismo , Dieta , Heces/microbiología , Heces/química , Azufre/metabolismo , Aminoácidos Sulfúricos/metabolismo
8.
Bioelectrochemistry ; 159: 108731, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38759479

RESUMEN

Carbon steel microbiologically influenced corrosion (MIC) by sulfate reducing bacteria (SRB) is known to occur via extracellular electron transfer (EET). A higher biofilm sessile cell count leads to more electrons being harvested for sulfate reduction by SRB in energy production. Metal surface roughness can impact the severity of MIC by SRB because of varied biofilm attachment. C1018 carbon steel coupons (1.2 cm2 top working surface) polished to 36 grit (4.06 µm roughness which is relatively rough) and 600 grit (0.13 µm) were incubated in enriched artificial seawater inoculated with highly corrosive Desulfovibrio ferrophilus IS5 at 28 â„ƒ for 7 d and 30 d. It was found that after 7 d of SRB incubation, 36 grit coupons had a 11% higher sessile cell count at (2.0 ± 0.17) × 108 cells/cm2, 52% higher weight loss at 22.4 ± 5.9 mg/cm2 (1.48 ± 0.39 mm/a uniform corrosion rate), and 18% higher maximum pit depth at 53 µm compared with 600 grit coupons. However, after 30 d, the differences diminished. Electrochemical tests with transient information supported the weight loss data trends. This work suggests that a rougher surface facilitates initial biofilm establishment but provides no long-term advantage for increased biofilm growth.


Asunto(s)
Biopelículas , Carbono , Desulfovibrio , Acero , Propiedades de Superficie , Corrosión , Acero/química , Desulfovibrio/metabolismo , Desulfovibrio/fisiología , Carbono/química , Carbono/metabolismo , Electrones , Transporte de Electrón , Sulfatos/metabolismo , Sulfatos/química
9.
FEMS Microbiol Ecol ; 100(7)2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38794902

RESUMEN

Mucin is a glycoprotein secreted throughout the mammalian gastrointestinal tract that can support endogenous microorganisms in the absence of complex polysaccharides. While several mucin-degrading bacteria have been identified, the interindividual differences in microbial communities capable of metabolizing this complex polymer are not well described. To determine whether community assembly on mucin is deterministic across individuals or whether taxonomically distinct but functionally similar mucin-degrading communities are selected across fecal inocula, we used a 10-day in vitro sequential batch culture fermentation from three human donors with mucin as the sole carbon source. For each donor, 16S rRNA gene amplicon sequencing was used to characterize microbial community succession, and the short-chain fatty acid profile was determined from the final community. All three communities reached a steady-state by day 7 in which the community composition stabilized. Taxonomic comparisons amongst communities revealed that one of the final communities had Desulfovibrio, another had Akkermansia, and all three shared other members, such as Bacteroides. Metabolic output differences were most notable for one of the donor's communities, with significantly less production of acetate and propionate than the other two communities. These findings demonstrate the feasibility of developing stable mucin-degrading communities with shared and unique taxa. Furthermore, the mechanisms and efficiencies of mucin degradation across individuals are important for understanding how this community-level process impacts human health.


Asunto(s)
Heces , Fermentación , Consorcios Microbianos , Mucinas , ARN Ribosómico 16S , Humanos , Mucinas/metabolismo , ARN Ribosómico 16S/genética , Heces/microbiología , Bacterias/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Ácidos Grasos Volátiles/metabolismo , Microbioma Gastrointestinal , Akkermansia/metabolismo , Desulfovibrio/metabolismo , Desulfovibrio/genética , Desulfovibrio/clasificación , Bacteroides/metabolismo , Bacteroides/genética , Bacteroides/clasificación , Bacteroides/crecimiento & desarrollo
10.
Microbiol Res ; 284: 127725, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38663233

RESUMEN

Increasing studies have focused on the relationship between Desulfovibrio bacteria (DSV) and host health in recent years. However, little is known about the mechanisms by which DSV affects host health and the strategies to accurately regulate DSV numbers. This review mainly presents the relationship between DSV and host health, potential modulatory strategies, and the potential mechanisms affecting host health. Evidence suggests that DSV can both promote host health and induce the occurrence and development of disease, and these effects are closely related to its metabolites (e.g., H2S and short-chain fatty acids) and biofilm. DSV abundance in the intestine is influenced by probiotics, prebiotics, diet, lifestyle, and drugs.


Asunto(s)
Biopelículas , Desulfovibrio , Microbioma Gastrointestinal , Probióticos , Desulfovibrio/metabolismo , Desulfovibrio/fisiología , Humanos , Microbioma Gastrointestinal/fisiología , Biopelículas/crecimiento & desarrollo , Intestinos/microbiología , Prebióticos , Animales , Ácidos Grasos Volátiles/metabolismo , Sulfuro de Hidrógeno/metabolismo , Dieta
11.
Sci Total Environ ; 925: 171763, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38494030

RESUMEN

Microbial biofilms are behind microbiologically influenced corrosion (MIC). Sessile cells in biofilms are many times more concentrated volumetrically than planktonic cells in the bulk fluids, thus providing locally high concentrations of chemicals. More importantly, "electroactive" sessile cells in biofilms are capable of utilizing extracellularly supplied electrons (e.g., from elemental Fe) for intracellular reduction of an oxidant such as sulfate in energy metabolism. MIC directly caused by anaerobic biofilms is classified into two main types based on their mechanisms: extracellular electron transfer MIC (EET-MIC) and metabolite MIC (M-MIC). Sulfate-reducing bacteria (SRB) are notorious for their corrosivity. They can cause EET-MIC in carbon steel, but they can also secrete biogenic H2S to corrode other metals such as Cu directly via M-MIC. This study investigated the use of conductive magnetic nanowires as electron mediators to accelerate and thus identify EET-MIC of C1020 by Desulfovibrio vulgaris. The presence of 40 ppm (w/w) nanowires in ATCC 1249 culture medium at 37 °C resulted in 45 % higher weight loss and 57 % deeper corrosion pits after 7-day incubation. Electrochemical tests using linear polarization resistance and potentiodynamic polarization supported the weight loss data trend. These findings suggest that conductive magnetic nanowires can be employed to identify EET-MIC. The use of insoluble 2 µm long nanowires proved that the extracellular section of the electron transfer process is a bottleneck in SRB MIC of carbon steel.


Asunto(s)
Desulfovibrio vulgaris , Desulfovibrio , Nanocables , Humanos , Acero , Electrones , Carbono/metabolismo , Biopelículas , Desulfovibrio/metabolismo , Corrosión , Sulfatos/metabolismo , Pérdida de Peso
12.
J Hazard Mater ; 466: 133622, 2024 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-38280317

RESUMEN

Ferrous sulfide nanoparticles (nFeS) have proven to be effective in removing heavy metals (HMs) from wastewater. One such approach, which has garnered much attention as a sustainable technology, is via the in situ microbial synthesis of nFeS. Here, a sulfate-reducing bacteria (SRB) strain, Geobacter sulfurreducens, was used to initially biosynthesize ferrous sulfide nanoparticles (SRB-nFeS) and thereafter remove HMs from acid mine drainage (AMD). SRB-nFeS was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) coupled to an energy dispersive spectrometer (EDS), three-dimensional excitation-emission matrix (3D-EEM) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). Such characterization showed that SRB mediated the reduction of SO42- to S2- to form nFeS, where the metabolized substances functioned as complexing agents which coordinated with nFeS to form biofunctional SRB-nFeS with improved stability. One advantage of this synthetic route was that the attachment of nFeS to the bacterial surface protected SRB cells from HM toxicity. Furthermore, due to a synergistic effect between nFeS and SRB, HM removal from both solution and AMD by SRB-nFeS was enhanced relative to the constituent components. Thus, after 5 consecutive cycles of HM removal, SRB-nFeS removed, Pb(Ⅱ) (92.6%), Cd(Ⅱ) (78.7%), Cu(Ⅱ) (76.0%), Ni(Ⅱ) (62.5%), Mn(Ⅱ) (62.2%), and Zn(Ⅱ) (88.5%) from AMD This study thus provides new insights into the biosynthesis of SRB-nFeS and its subsequent practical application in the removal of HMs from AMD.


Asunto(s)
Desulfovibrio , Compuestos Ferrosos , Metales Pesados , Sulfatos/química , Metales Pesados/química , Desulfovibrio/metabolismo , Bacterias/metabolismo , Ácidos/metabolismo
13.
Biodegradation ; 35(4): 439-449, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38261083

RESUMEN

Most microbiologically influenced corrosion (MIC) studies focus on the threat of pinhole leaks caused by MIC pitting. However, microbes can also lead to structural failures. Tetrakis hydroxymethyl phosphonium sulfate (THPS) biocide mitigated the microbial degradation of mechanical properties of X80 steel pipeline by Desulfovibrio ferrophilus (IS5 strain), a very corrosive sulfate reducing bacterium. It was found that 100 ppm (w/w) THPS added to the enriched artificial seawater (EASW) culture medium before incubation resulted in 2.8-log reduction in sessile cell count after a 7-d incubation at 28 °C under anaerobic conditions, leading to 94% uniform corrosion rate reduction (from 1.3 to 0.07 mm/a), and 84% pitting corrosion rate reduction (from 0.70 to 0.11 mm/a). The X80 dogbone coupon incubated with 100 ppm THPS for 7 d suffered 3% loss in ultimate tensile strain and 0% loss in ultimate tensile strength compared with the abiotic control in EASW. In comparison, the no-treatment X80 dogbone coupon suffered losses of 13% in ultimate tensile strain and 6% in ultimate tensile stress, demonstrating very good THPS efficacy.


Asunto(s)
Biodegradación Ambiental , Desulfovibrio , Desinfectantes , Acero , Acero/química , Corrosión , Desulfovibrio/metabolismo , Desulfovibrio/efectos de los fármacos , Desinfectantes/farmacología , Resistencia a la Tracción , Carbono
14.
J Hazard Mater ; 465: 133052, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38056257

RESUMEN

The sulfate-reducing efficiency of sulfate-reducing bacteria (SRB) is strongly influenced by the presence of oxygen, but little is known about the oxygen tolerance mechanism of SRB and the effect of oxygen on the metalliferous immobilization by SRB. The performance evaluation, identification of bioprecipitates, and microbial and metabolic process analyses were used here to investigate the As3+ immobilization mechanisms and survival strategies of the SRB1 consortium under different oxygen-containing environments. Results indicated that the sulfate reduction efficiency was significantly decreased under aerobic (47.37%) compared with anaerobic conditions (66.72%). SEM analysis showed that under anaerobic and aerobic conditions, the morphologies of mineral particles were different, whereas XRD and XPS analyses showed that the most of As3+ bioprecipitates under both conditions were arsenic minerals such as AsS and As4S4. The abundances of Clostridium_sensu_stricto_1, Desulfovibrio, and Thiomonas anaerobic bacteria were significantly higher under anaerobic than aerobic conditions, whereas the aerobic Pseudomonas showed an opposite trend. Network analysis revealed that Desulfovibrio was positively correlated with Pseudomonas. Metabolic process analysis confirmed that under aerobic conditions the SRB1 consortium generated additional extracellular polymeric substances (rich in functionalities such as Fe-O, SO, CO, and -OH) and the anti-oxidative enzyme superoxide dismutase to resist As3+ stress and oxygen toxicity. New insights are provided here into the oxygen tolerance and detoxification mechanism of SRB and provide a basis for the future remediation of heavy metal(loid)-contaminated environments.


Asunto(s)
Desulfovibrio , Consorcios Microbianos , Anaerobiosis , Desulfovibrio/metabolismo , Sulfatos/metabolismo , Oxígeno/metabolismo
15.
J Hazard Mater ; 459: 132213, 2023 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-37549581

RESUMEN

Sulfate-reducing bacteria (SRB) can immobilize heavy metals in soils through biomineralization, and the parent rock and minerals in the soil are critical to the immobilization efficiency of SRB. To date, there is little knowledge about the fate of Cd associated with the parent rocks and minerals of soil during Cd immobilized by SRB. In this study, we created a model system using clay-size fraction of soil and SRB to explore the role of SRB in immobilizing Cd in soils from stratigraphic successions with high geochemical background. In the system, clay-size fractions (particle size < 2 µm) with concentration of Cd (0.24-2.84 mg/kg) were extracted from soils for bacteria inoculation. After SRB reaction for 10 days, the Cd fraction tended to transform into iron-manganese bound. Further, two clay-size fractions, i.e., the non-crystalline iron oxide (Fe-OX) and the crystalline iron oxide (Fe-CBD), were separated by extraction. The reaction of SRB with them verified the transformation of primary iron-bearing minerals into secondary iron-bearing minerals, which contributed to Cd redistribution. This study shows that SRB could exploit the composition and structure of minerals to induce mineral recrystallization, thereby aggravating Cd redistribution and immobilization in clay-size fractions from stratigraphic successions with high geochemical background.


Asunto(s)
Desulfovibrio , Contaminantes del Suelo , Arcilla , Suelo/química , Cadmio/química , Contaminantes del Suelo/análisis , Minerales/química , Hierro/metabolismo , Desulfovibrio/metabolismo , Sulfatos
16.
J Hazard Mater ; 459: 132256, 2023 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-37567138

RESUMEN

Sulfate-reducing bacteria (SRB) were effective in stabilizing Sb. However, the influence of electron donors and acceptors during SRB remediation, as well as the ecological principles involved, remained unclear. In this study, Desulfovibrio desulfuricans ATCC 7757 was utilized to stabilize soil Sb within microcosm. Humic acid (HA) or sodium sulfate (Na2SO4) were employed to enhance SRB capacity. The SRB+HA treatment exhibited the highest Sb stabilization rate, achieving 58.40%. Bacterial community analysis revealed that SRB altered soil bacterial diversity, community composition, and assembly processes, with homogeneous selection as the predominant assembly processes. When HA and Na2SO4 significantly modified the stimulated microbial community succession trajectories, shaped the taxonomic composition and interactions of the bacterial community, they showed converse effect in shaping bacterial community which were both helpful for promoting dissimilatory sulfate reduction. Na2SO4 facilitated SRB-mediated anaerobic reduction and promoted interactions between SRB and bacteria involved in nitrogen and sulfur cycling. The HA stimulated electron generation and storage, and enhanced the interactions between SRB and bacteria possessing heavy metal tolerance or carbohydrate degradation capabilities.


Asunto(s)
Antimonio , Desulfovibrio , Antimonio/metabolismo , Oxidación-Reducción , Suelo , Disponibilidad Biológica , Desulfovibrio/metabolismo , Bacterias/metabolismo , Sulfatos/metabolismo
17.
Arch Microbiol ; 205(5): 162, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-37010699

RESUMEN

Sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) inhabit oilfield production systems. Sulfur oxidation driven by SOB and dissimilatory sulfate reduction driven by SRB play important roles in sulfur cycle of oil reservoirs. More importantly, hydrogen sulfide produced by SRB is an acidic, flammable, and smelly toxic gas associated with reservoir souring, corrosion of oil-production facilities, and personnel safety. Effective control of SRB is urgently needed for the oil industry. This depends on an in-depth understanding of the microbial species that drive sulfur cycle and other related microorganisms in oil reservoir environments. Here, we identified SOB and SRB in produced brines of Qizhong block (Xinjiang Oilfield, China) from metagenome sequencing data based on reported SOB and SRB, reviewed metabolic pathways of sulfur oxidation and dissimilatory sulfate reduction, and ways for SRB control. The existing issues and future research of microbial sulfur cycle and SRB control are also discussed. Knowledge of the distribution of the microbial populations, their metabolic characteristics and interactions can help to develop an effective process to harness these microorganisms for oilfield production.


Asunto(s)
Desulfovibrio , Yacimiento de Petróleo y Gas , Oxidación-Reducción , Sulfatos/metabolismo , Desulfovibrio/metabolismo , Bacterias/genética , Bacterias/metabolismo , Azufre/metabolismo
18.
mBio ; 14(2): e0007623, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-36786581

RESUMEN

Desulfovibrio vulgaris has been a primary pure culture sulfate reducer for developing microbial corrosion concepts. Multiple mechanisms for how it accepts electrons from Fe0 have been proposed. We investigated Fe0 oxidation with a mutant of D. vulgaris in which hydrogenase genes were deleted. The hydrogenase mutant grew as well as the parental strain with lactate as the electron donor, but unlike the parental strain, it was not able to grow on H2. The parental strain reduced sulfate with Fe0 as the sole electron donor, but the hydrogenase mutant did not. H2 accumulated over time in Fe0 cultures of the hydrogenase mutant and sterile controls but not in parental strain cultures. Sulfide stimulated H2 production in uninoculated controls apparently by both reacting with Fe0 to generate H2 and facilitating electron transfer from Fe0 to H+. Parental strain supernatants did not accelerate H2 production from Fe0, ruling out a role for extracellular hydrogenases. Previously proposed electron transfer between Fe0 and D. vulgaris via soluble electron shuttles was not evident. The hydrogenase mutant did not reduce sulfate in the presence of Fe0 and either riboflavin or anthraquinone-2,6-disulfonate, and these potential electron shuttles did not stimulate parental strain sulfate reduction with Fe0 as the electron donor. The results demonstrate that D. vulgaris primarily accepts electrons from Fe0 via H2 as an intermediary electron carrier. These findings clarify the interpretation of previous D. vulgaris corrosion studies and suggest that H2-mediated electron transfer is an important mechanism for iron corrosion under sulfate-reducing conditions. IMPORTANCE Microbial corrosion of iron in the presence of sulfate-reducing microorganisms is economically significant. There is substantial debate over how microbes accelerate iron corrosion. Tools for genetic manipulation have only been developed for a few Fe(III)-reducing and methanogenic microorganisms known to corrode iron and in each case those microbes were found to accept electrons from Fe0 via direct electron transfer. However, iron corrosion is often most intense in the presence of sulfate-reducing microbes. The finding that Desulfovibrio vulgaris relies on H2 to shuttle electrons between Fe0 and cells revives the concept, developed in some of the earliest studies on microbial corrosion, that sulfate reducers consumption of H2 is a major microbial corrosion mechanism. The results further emphasize that direct Fe0-to-microbe electron transfer has yet to be rigorously demonstrated in sulfate-reducing microbes.


Asunto(s)
Desulfovibrio vulgaris , Desulfovibrio , Hidrogenasas , Hierro , Desulfovibrio vulgaris/genética , Desulfovibrio vulgaris/metabolismo , Hidrogenasas/genética , Hidrogenasas/metabolismo , Corrosión , Oxidación-Reducción , Ácido Láctico , Sulfatos , Desulfovibrio/genética , Desulfovibrio/metabolismo
19.
Sci Total Environ ; 861: 160551, 2023 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-36460112

RESUMEN

Schwertmannite (Sch) is an iron-hydroxysulfate mineral commonly found in acid mine drainage contaminated environment. The transformation mechanism of Sch mediated by pure cultured iron-reducing bacteria (FeRB) or sulfate-reducing bacteria (SRB) has been studied. However, FeRB and SRB widely coexist in the environment, the mechanism of Sch transformation by the consortia of FeRB and SRB is still unclear. This study investigated the Sch reduction by co-cultured Shewanella oneidensis (FeRB) and Desulfosporosinus meridiei (SRB). The results showed that co-culture of FeRB and SRB could accelerate the reductive dissolution of Sch, but not synergistically, and there were two distinct phases in the reduction of Sch mediated by FeRB and SRB: an initial phase in which FeRB predominated and Fe3+ in Sch was reduced, accompanied with the release of SO42-, and the detected secondary minerals were mainly vivianite; the second phase in which SRB predominated and mediated the reduction of SO42-, producing minerals including mackinawite and siderite in addition to vivianite. Compared to pure culture, the abundance of FeRB and SRB in the consortia decreased, and more minerals aggregated inside and outside the cell; correspondingly, the transcription levels of genes (cymA, omcA, and mtrCBA) related to Fe3+ reduction in co-culture was down-regulated, while the transcription levels of SO42--reducing genes (sat, aprAB, dsr(C)) was generally up-regulated. These phenomena suggested that secondary minerals produced in co-culture limited but did not inhibit bacterial growth, and the presence of SRB was detrimental to dissimilatory Fe3+ reduction, while existed FeRB was in favor of dissimilatory SO42- reduction. SRB mediated SO42- reduction by up-regulating the expression of SO42- reduction-related genes when its abundance was limited, which may be a strategy to cope with external coercion. These findings allow for a better understanding of the process and mechanism of microbial mediated reduction of Sch in the environment.


Asunto(s)
Desulfovibrio , Hierro , Hierro/metabolismo , Técnicas de Cocultivo , Compuestos Férricos/metabolismo , Minerales/metabolismo , Desulfovibrio/metabolismo , Bacterias/metabolismo , Sulfatos/metabolismo , Oxidación-Reducción
20.
J Environ Manage ; 330: 117148, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36584458

RESUMEN

Bioremediation techniques utilizing sulfate-reducing bacteria (SRB) for acid mine drainage (AMD) treatment have attracted growing attention in recent years, yet substrate bioavailability for SRB is a key factor influencing treatment effectiveness and long-term stability. This study investigated the effects of external organic substrates, including four complex organic wastes (i.e., sugarcane bagasse, straw compost, shrimp shell (SS), and crab shell (CS)) and a small-molecule organic acid (i.e., propionate), on AMD removal performance and associated microbial communities during the 30-day operation of sulfate-reducing microcosms. The results showed that the pH values increased in all five microcosms, while CS exhibited the highest neutralization ability and a maximum alkalinity generation of 1507 mg/L (as CaCO3). Sulfate reduction was more effective in SS and CS microcosms, with sulfate removal efficiencies of 95.6% and 86.0%, respectively. All sulfate-reducing microcosms could remove heavy metals to different degrees, with the highest removal rate of >99.0% observed for aluminum. The removal efficiency of manganese, the most recalcitrant metal, was the highest (96%) in the CS microcosm. Correspondingly, SRB was more abundant in the CS and SS microcosms as revealed by sequencing analysis, while Desulfotomaculum was the dominant SRB in the CS microcosm, accounting for 10.8% of total effective bacterial sequences. Higher abundances of functional genes involved in fermentation and sulfur cycle were identified in CS and SS microcosms. This study suggests that complex organic wastes such as CS and SS could create and maintain preferable micro-environments for active growth and metabolism of functional microorganisms, thus offering a cost-efficient, stable, and environmental-friendly solution for AMD treatment and management.


Asunto(s)
Desulfovibrio , Metales Pesados , Microbiota , Saccharum , Celulosa , Sulfatos/química , Metales Pesados/química , Ácidos , Desulfovibrio/metabolismo , Reactores Biológicos/microbiología
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