-
Microbiome Apr 2023Mangrove ecosystems are considered as hot spots of biogeochemical cycling, yet the diversity, function and coupling mechanism of microbially driven biogeochemical...
BACKGROUND
Mangrove ecosystems are considered as hot spots of biogeochemical cycling, yet the diversity, function and coupling mechanism of microbially driven biogeochemical cycling along the sediment depth of mangrove wetlands remain elusive. Here we investigated the vertical profile of methane (CH), nitrogen (N) and sulphur (S) cycling genes/pathways and their potential coupling mechanisms using metagenome sequencing approaches.
RESULTS
Our results showed that the metabolic pathways involved in CH, N and S cycling were mainly shaped by pH and acid volatile sulphide (AVS) along a sediment depth, and AVS was a critical electron donor impacting mangrove sediment S oxidation and denitrification. Gene families involved in S oxidation and denitrification significantly (P < 0.05) decreased along the sediment depth and could be coupled by S-driven denitrifiers, such as Burkholderiaceae and Sulfurifustis in the surface sediment (0-15 cm). Interestingly, all S-driven denitrifier metagenome-assembled genomes (MAGs) appeared to be incomplete denitrifiers with nitrate/nitrite/nitric oxide reductases (Nar/Nir/Nor) but without nitrous oxide reductase (Nos), suggesting such sulphide-utilizing groups might be an important contributor to NO production in the surface mangrove sediment. Gene families involved in methanogenesis and S reduction significantly (P < 0.05) increased along the sediment depth. Based on both network and MAG analyses, sulphate-reducing bacteria (SRB) might develop syntrophic relationships with anaerobic CH oxidizers (ANMEs) by direct electron transfer or zero-valent sulphur, which would pull forward the co-existence of methanogens and SRB in the middle and deep layer sediments.
CONCLUSIONS
In addition to offering a perspective on the vertical distribution of microbially driven CH, N and S cycling genes/pathways, this study emphasizes the important role of S-driven denitrifiers on NO emissions and various possible coupling mechanisms of ANMEs and SRB along the mangrove sediment depth. The exploration of potential coupling mechanisms provides novel insights into future synthetic microbial community construction and analysis. This study also has important implications for predicting ecosystem functions within the context of environmental and global change. Video Abstract.
Topics: Methane; Nitrogen; Microbiota; Desulfovibrio; Sulfur; Sulfides; Geologic Sediments
PubMed: 37020239
DOI: 10.1186/s40168-023-01501-5 -
Bioprocess and Biosystems Engineering Sep 2023In the wet flue gas desulfurization (WFGD) process, SO is adsorbed by alkaline liquor to produce alkaline wastewater containing sulfate and sulfite. Although the...
In the wet flue gas desulfurization (WFGD) process, SO is adsorbed by alkaline liquor to produce alkaline wastewater containing sulfate and sulfite. Although the traditional chemical treatment method can achieve a high removal rate, it consumes a large number of chemicals and yields a large number of low-value by-products. The biological treatment process is a greener and more environmentally friendly treatment method. The current work studies microbial flue gas desulfurization directly using sulfite as the electron acceptor in the reduction process. Desulfovibrio were obtained by isolation and purification, and their growth conditions in sulfite wastewater and desulfurization process conditions were investigated by intermittent and continuous experiments. The results of intermittent experiments indicated that the optimal growth conditions of Desulfovibrio were a temperature of 38 °C, a pH value of 8.0, a COD/SO of 2 and that the growth of bacteria would be inhibited at a pH above 9.0 or below 7.3. Furthermore, Desulfovibrio could grow in simulated wastewater with a high SO concentration of 8000 mg/L. The results of continuous experiments showed that the removal of sulfite and the recovery of elemental sulfur was realized by a micro-oxygen depletion process, and the removal rate of sulfite of 99%, the yield of elemental sulfur is more than 80% and can reach 90% under the condition of low influent concentration. The bacteria grew well at a temperature of 40 °C and a pH value of the influent water of 7.5. To ensure the treatment effect, the hydraulic retention time (HRT) should be more than doubled for each 1000 mg/L increase in the influent sulfite concentration under the same reflux ratio. When the influent sulfite concentration was 1000 mg/L, 2000 mg/L, 3000 mg/L, and 4000 mg/L, the corresponding HRT was 3.01 h, 6.94 h, 17.4 h, and 31.9 h, respectively. The dominant species in the reactor was Desulfovibrio bacteria at 63.9% abundance. This study demonstrated the feasibility of using sulfite as an electron acceptor for microbial desulfurization, which can optimize the initial process and provide the possibility of treating high-concentration sulfite wastewater.
Topics: Wastewater; Sewage; Waste Disposal, Fluid; Sulfites; Bacteria; Sulfur; Desulfovibrio
PubMed: 37418179
DOI: 10.1007/s00449-023-02895-0 -
Frontiers in Cellular and Infection... 2023The aggregation of the neuronal protein alpha-synuclein (alpha-syn) is a key feature in the pathology of Parkinson's disease (PD). Alpha-syn aggregation has been...
INTRODUCTION
The aggregation of the neuronal protein alpha-synuclein (alpha-syn) is a key feature in the pathology of Parkinson's disease (PD). Alpha-syn aggregation has been suggested to be induced in the gut cells by pathogenic gut microbes such as bacteria, which has been shown to be associated with PD. This study aimed to investigate whether bacteria induce alpha-syn aggregation.
METHODS
Fecal samples of ten PD patients and their healthy spouses were collected for molecular detection of species, followed by bacterial isolation. Isolated strains were used as diets to feed nematodes which overexpress human alpha-syn fused with yellow fluorescence protein. Curli-producing MC4100, which has been shown to facilitate alpha-syn aggregation in animal models, was used as a control bacterial strain, and LSR11, incapable of producing curli, was used as another control strain. The head sections of the worms were imaged using confocal microscopy. We also performed survival assay to determine the effect of bacteria on the survival of the nematodes.
RESULTS AND DISCUSSION
Statistical analysis revealed that worms fed bacteria from PD patients harbored significantly more (<0.001, Kruskal-Wallis and Mann-Whitney U test) and larger alpha-syn aggregates (<0.001) than worms fed bacteria from healthy individuals or worms fed strains. In addition, during similar follow-up time, worms fed strains from PD patients died in significantly higher quantities than worms fed LSR11 bacteria (<0.01). These results suggest that bacteria contribute to PD development by inducing alpha-syn aggregation.
Topics: Animals; Humans; Parkinson Disease; alpha-Synuclein; Caenorhabditis elegans; Escherichia coli; Desulfovibrio
PubMed: 37197200
DOI: 10.3389/fcimb.2023.1181315 -
Chemosphere Jul 2022Aquaculture wastewater contained a high remnant of oxytetracycline (OTC) and nitrate. In this study, OTC co-metabolized with denitrification/desulfurization was...
Aquaculture wastewater contained a high remnant of oxytetracycline (OTC) and nitrate. In this study, OTC co-metabolized with denitrification/desulfurization was investigated in terms of kinetic analysis, pathway, microbial communities and produces analysis in sulfate-reducing bacteria (SRB) mediated system. Long-term acclimatization with sulfate (300 mg-S/L) could markedly accelerate the removed rate of OTC from 0.9 to 1.4 mg/g-SS/d, with the kinetic constants increasing from 0.2760 to 0.5232 d, mainly via enzymes including adenosine-5'-phos-phosulfate reductase and cytochrome P450, and non-enzymatic process related to intermediates (adenosine-5'-phos-phosulfate and S). Furthermore, OTC was likely detoxified by SRB enriched sludge mainly via hydrolysis, dehydration, oxidation and reduction. The denitrification process would postpone the OTC degradation via outcompeting electron donors with the desulfurization process. Redundancy analysis suggested that sulfur-oxidizing bacteria (Acidithiobacillus, Ochrobactrum) were highly related to OTC degradation processes. This study provides deep insight and a new opportunity for the treatment of aquaculture wastewater containing OTC, sulfate and nitrate by SRB sludge.
Topics: Adenosine; Bioreactors; Denitrification; Desulfovibrio; Kinetics; Nitrates; Oxytetracycline; Sewage; Sulfates; Wastewater
PubMed: 35271902
DOI: 10.1016/j.chemosphere.2022.134256 -
Scientific Reports Aug 2023Animal and human feces typically include intestinal sulfate-reducing bacteria (SRB). Hydrogen sulfide and acetate are the end products of their dissimilatory sulfate...
Animal and human feces typically include intestinal sulfate-reducing bacteria (SRB). Hydrogen sulfide and acetate are the end products of their dissimilatory sulfate reduction and may create a synergistic effect. Here, we report NADH and NADPH peroxidase activities from intestinal SRB Desulfomicrobium orale and Desulfovibrio piger. We sought to compare enzymatic activities under the influence of various temperature and pH regimes, as well as to carry out kinetic analyses of enzymatic reaction rates, maximum amounts of the reaction product, reaction times, maximum rates of the enzyme reactions, and Michaelis constants in cell-free extracts of intestinal SRB, D. piger Vib-7, and D. orale Rod-9, collected from exponential and stationary growth phases. The optimal temperature (35 °C) and pH (7.0) for both enzyme's activity were determined. The difference in trends of Michaelis constants (K) during exponential and stationary phases are noticeable between D. piger Vib-7 and D. orale Rod-9; D. orale Rod-9 showed much higher K (the exception is NADH peroxidase of D. piger Vib-7: 1.42 ± 0.11 mM) during the both monitored phases. Studies of the NADH and NADPH peroxidases-as putative antioxidant defense systems of intestinal SRB and detailed data on the kinetic properties of this enzyme, as expressed by the decomposition of hydrogen peroxide-could be important for clarifying evolutionary mechanisms of antioxidant defense systems, their etiological role in the process of dissimilatory sulfate reduction, and their possible role in the development of bowel diseases.
Topics: Animals; Humans; Antioxidants; NAD; NADP; Cell Extracts; Desulfovibrio; Peroxidases; Defense Mechanisms; Sulfates
PubMed: 37626119
DOI: 10.1038/s41598-023-41185-3 -
Emerging Infectious Diseases Aug 2023An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at...
An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at the site. The patient recovered after surgical debridement, artificial vessel replacement, and appropriate antimicrobial therapy. Clinicians should suspect Desulfovibrio spp. infection in similar cases.
Topics: Male; Humans; Aged, 80 and over; Desulfovibrio desulfuricans; Aneurysm; Japan
PubMed: 37486321
DOI: 10.3201/eid2908.230403 -
Frontiers in Cellular and Infection... 2020In order to improve our understanding on the microbial complexity associated with Grade C/molar-incisor pattern periodontitis (GC/MIP), we surveyed the oral and fecal...
In order to improve our understanding on the microbial complexity associated with Grade C/molar-incisor pattern periodontitis (GC/MIP), we surveyed the oral and fecal microbiomes of GC/MIP and compared to non-affected individuals (Control). Seven Afro-descendants with GC/MIP and seven age/race/gender-matched controls were evaluated. Biofilms from supra/subgingival sites (OB) and feces were collected and submitted to sequencing. () JP2 clone genotyping and salivary nitrite levels were determined. Supragingival biofilm of GC/MIP presented greater abundance of opportunistic bacteria. was increased in subgingival healthy sites of GC/MIP compared to Control. and were more abundant whereas was reduced in OB of GC/MIP compared to controls. abundance was 50 times higher in periodontal sites with PD≥ 4 mm of GC/MIP than in controls. GC/MIP oral microbiome was characterized by a reduction in commensals such as , and and enrichment in periodontopathogens, especially and sulfate reducing . The oral microbiome of the JP2-like+ patient was phylogenetically distant from other GC/MIP individuals. GC/MIP presented a higher abundance of sulfidogenic bacteria in the feces, such as , and than controls. These preliminary data show that the dysbiosis of the microbiome in Afro-descendants with GC/MIP was not restricted to affected sites, but was also observed in supragingival and subgingival healthy sites, as well as in the feces. The understanding on differences of the microbiome between healthy and GC/MIP patients will help in developing strategies to improve and monitor periodontal treatment.
Topics: Aggregatibacter actinomycetemcomitans; Desulfovibrio; Erysipelothrix; Feces; Humans; Incisor; Microbiota; Molar; Peptostreptococcus; Periodontitis; RNA, Ribosomal, 16S
PubMed: 33117737
DOI: 10.3389/fcimb.2020.583761 -
ACS Nano Jan 2021Graphene is a promising material for many biointerface applications in engineering, medical, and life-science domains. Here, we explore the protection ability of...
Graphene is a promising material for many biointerface applications in engineering, medical, and life-science domains. Here, we explore the protection ability of graphene atomic layers to metals exposed to aggressive sulfate-reducing bacteria implicated in corrosion. Although the graphene layers on copper (Cu) surfaces did not prevent the bacterial attachment and biofilm growth, they effectively restricted the biogenic sulfide attack. Interestingly, single-layered graphene (SLG) worsened the biogenic sulfide attack by 5-fold compared to bare Cu. In contrast, multilayered graphene (MLG) on Cu restricted the attack by 10-fold and 1.4-fold compared to SLG-Cu and bare Cu, respectively. We combined experimental and computational studies to discern the anomalous behavior of SLG-Cu compared to MLG-Cu. We also report that MLG on Ni offers superior protection ability compared to SLG. Finally, we demonstrate the effect of defects, including double vacancy defects and grain boundaries on the protection ability of atomic graphene layers.
Topics: Biofilms; Copper; Corrosion; Desulfovibrio; Graphite
PubMed: 33381965
DOI: 10.1021/acsnano.0c03987 -
Archives of Microbiology Apr 2023Sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) inhabit oilfield production systems. Sulfur oxidation driven by SOB and dissimilatory sulfate... (Review)
Review
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.
Topics: Oil and Gas Fields; Oxidation-Reduction; Sulfates; Desulfovibrio; Bacteria; Sulfur
PubMed: 37010699
DOI: 10.1007/s00203-023-03520-0 -
Nature Jun 2022Cellular iron homeostasis is vital and maintained through tight regulation of iron import, efflux, storage and detoxification. The most common modes of iron storage use...
Cellular iron homeostasis is vital and maintained through tight regulation of iron import, efflux, storage and detoxification. The most common modes of iron storage use proteinaceous compartments, such as ferritins and related proteins. Although lipid-bounded iron compartments have also been described, the basis for their formation and function remains unknown. Here we focus on one such compartment, herein named the 'ferrosome', that was previously observed in the anaerobic bacterium Desulfovibrio magneticus. Using a proteomic approach, we identify three ferrosome-associated (Fez) proteins that are responsible for forming ferrosomes in D. magneticus. Fez proteins are encoded in a putative operon and include FezB, a P-ATPase found in phylogenetically and metabolically diverse species of bacteria and archaea. We show that two other bacterial species, Rhodopseudomonas palustris and Shewanella putrefaciens, make ferrosomes through the action of their six-gene fez operon. Additionally, we find that fez operons are sufficient for ferrosome formation in foreign hosts. Using S. putrefaciens as a model, we show that ferrosomes probably have a role in the anaerobic adaptation to iron starvation. Overall, this work establishes ferrosomes as a new class of iron storage organelles and sets the stage for studying their formation and structure in diverse microorganisms.
Topics: Bacterial Proteins; Desulfovibrio; Ferric Compounds; Gram-Negative Bacteria; Multigene Family; Organelles; Phylogeny; Proteomics; Rhodopseudomonas; Shewanella putrefaciens
PubMed: 35585231
DOI: 10.1038/s41586-022-04741-x