scholarly journals The genetic basis of energy conservation in the sulfate-reducing bacterium Desulfovibrio alaskensis G20

2014 ◽  
Author(s):  
Morgan Price ◽  
Jayashree Ray ◽  
Kelly M Wetmore ◽  
Jennifer V. Kuehl ◽  
Stefan Bauer ◽  
...  
Keyword(s):  
Energy Conservation ◽  
Genetic Basis ◽  
Growth Conditions ◽  
Sulfate Reducing ◽  
Transport Complex ◽  
Reducing Bacteria ◽  
Electron Carriers ◽  
Ion Pumping ◽  
Global Carbon ◽  
Transmembrane Electron Transport

Sulfate-reducing bacteria play major roles in the global carbon and sulfur cycles, but it remains unclear how reducing sulfate yields energy. To determine the genetic basis of energy conservation, we measured the fitness of thousands of pooled mutants ofDesulfovibrio alaskensisG20 during growth in 12 different combinations of electron donors and acceptors. We show that ion pumping by the ferredoxin:NADH oxidoreductase Rnf is required whenever substrate-level phosphorylation is not possible. The uncharacterized complex Hdr/flox-1 (Dde_1207:13) is sometimes important alongside Rnf and may perform an electron bifurcation to generate more reduced ferredoxin from NADH to allow further ion pumping. Similarly, during the oxidation of malate or fumarate, the electron-bifurcating transhydrogenase NfnAB-2 (Dde_1250:1) is important and may generate reduced ferredoxin to allow additional ion pumping by Rnf. During formate oxidation, the periplasmic [NiFeSe] hydrogenase HysAB is required, which suggests that hydrogen forms in the periplasm, diffuses to the cytoplasm, and is used to reduce ferredoxin, thus providing a substrate for Rnf. During hydrogen utilization, the transmembrane electron transport complex Tmc is important and may move electrons from the periplasm into the cytoplasmic sulfite reduction pathway. Finally, mutants of many other putative electron carriers ave no clear phenotype, which suggests that they are not important under our growth conditions.

Reduction of azo dyes by desulfovibrio desulfuricans

2000 ◽  
Vol 41 (12) ◽  
pp. 15-22 ◽  
Author(s):  
E. S. Yoo ◽  
J. Libra ◽  
U. Wiesmann
Keyword(s):  
Azo Dyes ◽  
Desulfovibrio Desulfuricans ◽  
Chemical Processes ◽  
Electron Acceptors ◽  
Potential Toxicity ◽  
Sulfate Reducing ◽  
Textile Finishing ◽  
Reactive Orange ◽  
Reducing Bacteria ◽  
Electron Carriers

Azo dyes are widely used in textile finishing, and have become of concern in wastewater treatment because of their color, bio-recalcitrance, and potential toxicity to animals and humans. Thus, wastewater with azo dyes must be decolorized and furthermore mineralized in appropriate systems combining biological and chemical processes. In this study, the potential for sulfate reducing bacteria (SRB) to decolorize azo dyes was studied, employing the pure culture of Desulfovibrio desulfuricans (D. desulfuricans) with varying sulfate levels. Under sulfate-rich conditions, the sulfide produced from sulfate respiration with pyruvate (electron donor) by D. desulfuricans chemically decolorized the azo dyes C. I. Reactive Orange 96 (RO 96) and C. I. Reactive Red 120 (RR 120). Under sulfate-depleted conditions (≤0.1 mmol/L), the decolorization of RO 96 and RR 120 occurred in correlation with the fermentation of pyruvate by D. desulfuricans. It is suggested that the electrons liberated from the pyruvate oxidation were transferred via enzymes and/or coenzymes (electron carriers) to the dyes as alternative terminal electron acceptors, giving rise to decolorization, instead of to the protons (H+), resulting in the production of H2. Both decolorization pathways were compared in light of bioenergetics and engineering aspects.

scholarly journals Brockarchaeota, a novel archaeal lineage capable of methylotrophy

2020 ◽  
Author(s):  
Valerie De Anda ◽  
Lin-Xing Chen ◽  
Nina Dombrowski ◽  
Zhengshuang Hua ◽  
Hong-Chen Jiang ◽  
...  
Keyword(s):  
Hot Springs ◽  
Phylogenetic Analyses ◽  
Methanogenic Archaea ◽  
Sulfate Reducing ◽  
Anoxic Environments ◽  
Archaeal Lineage ◽  
Acetogenic Bacteria ◽  
Reducing Bacteria ◽  
Globally Distributed ◽  
Global Carbon

Abstract Single carbon (C1) compounds such as methanol, methylamines and formaldehyde are ubiquitous in nature and they are large components of the carbon cycle. In anoxic environments C1-utilizing microbes (methylotrophs) play an important role in controlling global carbon degradation. Currently described anaerobic methylotrophs are limited to methanogenic archaea, acetogenic bacteria, and sulfate-reducing bacteria. Here, we report the first archaeal lineage outside of methanogenic taxa that are capable of anaerobic methylotrophy. Phylogenetic analyses suggest these archaea form a new phylum within the TACK superphylum, which we propose be named Brockarchaeota. A survey revealed Brockarchaeota are globally distributed in geothermal springs. Metabolic inference from 15 metagenome-assembled genomes from hot springs and deep-sea sediments indicates that Brockarchaeota are strict anaerobes. They contain a variety C1 metabolisms including the methanol and trimethylamine methyltransferases system, the ribulose bisphosphate pathway coupled with the non-oxidative pentoses phosphate pathway, and reductive glycine pathway. Brockarchaeota have an incomplete methyl-branch of the Wood-Ljungdahl pathway probably used for formaldehyde oxidation, since they lack several core genes involved in methanogenesis including methyl-CoM reductases. Brockarchaeota also appear to play an important role in the breakdown of plant-derived polysaccharides, especially cellulose, starch and xylan. Their broad distribution and their capacity to use both C1 compounds and complex polysaccharides via anaerobic metabolism suggest that the Brockarchaeota occupy previously overlooked roles in carbon cycling.

scholarly journals The genetic basis of energy conservation in the sulfate-reducing bacterium Desulfovibrio alaskensis G20

2014 ◽  
Vol 5 ◽  
Author(s):  
Morgan N. Price ◽  
Jayashree Ray ◽  
Kelly M. Wetmore ◽  
Jennifer V. Kuehl ◽  
Stefan Bauer ◽  
...  
Keyword(s):  
Energy Conservation ◽  
Genetic Basis ◽  
Sulfate Reducing

Application of Sulfate-Reducing and Sulfide-Oxidizing Bacterial Symbiosis for Wastewater Treatment

1995 ◽  
Vol 30 (2) ◽  
pp. 305-324 ◽  
Author(s):  
V. Tare ◽  
P.C. Sabumon
Keyword(s):  
Organic Matter ◽  
Microbial Population ◽  
Domestic Wastewater ◽  
Growth Conditions ◽  
Sulfate Reducing ◽  
Bacterial Symbiosis ◽  
Scale Models ◽  
Microbial System ◽  
Set Up ◽  
Reducing Bacteria

Abstract This investigation attempted to advance the state of the art of the process which utilizes the symbiotic relationship between the sulfate-reducing bacteria (SRB) and sulfide oxidizing bacteria (SOB) for degradation of organic matter present in wastewater. Major emphasis has been on the development of the desired microbial system without any external seed and comparative evaluation of the two types of multistage reversing flow bioreactor (MRB) systems. Biological vessels (BVs) in the MRB systems simulate conditions which correspond to configurations described as upflow sludge blanket and stationary fixed film. Two bench-scale models – one designed to achieve self granulation of sludge (SGS), and the second designed to promote growth of SRB/SOB on additional nonreactive surface – were set up and operated over a period of 4 months. Domestic wastewater supplemented with organic matter from sugar cane molasses was used as feed to develop the desired microbial population. Several visual and microscopic observations confirmed the presence of a significant number of SRB and SOB in all the biological vessels. Results indicated that it is possible to develop SGS and a microbial population of SRB and SOB which could attach to the nonreactive surface without any external seeding. Domestic wastewater could serve as a source of these organisms. Immobilized growth conditions and suspended growth conditions in BVs yield similar results in terms of organic matter utilization. The empirical formula for MRB biomass can be expressed as C11O12H36N5S.

scholarly journals Stable Carbon Isotope Ratios of Lipid Biomarkers of Sulfate-Reducing Bacteria

2004 ◽  
Vol 70 (2) ◽  
pp. 745-751 ◽  
Author(s):  
K. L. Londry ◽  
L. L. Jahnke ◽  
D. J. Des Marais
Keyword(s):  
Double Bond ◽  
Carbon Isotope ◽  
Stable Carbon Isotope ◽  
Growth Conditions ◽  
Heterotrophic Growth ◽  
Stable Carbon ◽  
Stable Carbon Isotope Ratios ◽  
Carbon Isotope Ratios ◽  
Sulfate Reducing ◽  
Reducing Bacteria

ABSTRACT We examined the potential use of natural-abundance stable carbon isotope ratios of lipids for determining substrate usage by sulfate-reducing bacteria (SRB). Four SRB were grown under autotrophic, mixotrophic, or heterotrophic growth conditions, and the δ13C values of their individual fatty acids (FA) were determined. The FA were usually 13C depleted in relation to biomass, with Δδ13C(FA − biomass) of −4 to −17‰; the greatest depletion occurred during heterotrophic growth. The exception was Desulfotomaculum acetoxidans, for which substrate limitation resulted in biomass and FA becoming isotopically heavier than the acetate substrate. The δ13C values of FA in Desulfotomaculum acetoxidans varied with the position of the double bond in the monounsaturated C16 and C18 FA, with FA becoming progressively more 13C depleted as the double bond approached the methyl end. Mixotrophic growth of Desulfovibrio desulfuricans resulted in little depletion of the i17:1 biomarker relative to biomass or acetate, whereas growth with lactate resulted in a higher proportion of i17:1 with a greater depletion in 13C. The relative abundances of 10Me16:0 in Desulfobacter hydrogenophilus and Desulfobacterium autotrophicum were not affected by growth conditions, yet the Δδ13C(FA − substrate) values of 10Me16:0 were considerably greater during autotrophic growth. These experiments indicate that FA δ13C values can be useful for interpreting carbon utilization by SRB in natural environments.

scholarly journals Rhamnolipids fromPseudomonas aeruginosaDisperse the Biofilms of Sulfate-Reducing Bacteria

2018 ◽  
Author(s):  
Thammajun L. Wood ◽  
Lei Zhu ◽  
James Miller ◽  
Daniel S. Miller ◽  
Bei Yin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Genetic Basis ◽  
Metal Corrosion ◽  
Desulfovibrio Vulgaris ◽  
Sulfate Reducing ◽  
Drilling Equipment ◽  
Biofilm Dispersal ◽  
Reducing Bacteria ◽  
Minimum Medium

ABSTRACTBiofilm formation is an important problem for many industries.Desulfovibrio vulgarisis the representative sulfate-reducing bacterium (SRB) which causes metal corrosion in oil wells and drilling equipment, and the corrosion is related to its biofilm formation. Biofilms are extremely difficult to remove since the cells are cemented in a polymer matrix. In an effort to eliminate SRB biofilms, we examined the ability of supernatants fromPseudomonas aeruginosaPA14 to disperse SRB biofilms. We found that theP. aeruginosasupernatants dispersed more than 98% of the biofilm. To determine the genetic basis of this SRB biofilm dispersal, we examined a series ofP. aeruginosamutants and found that mutantsrhlA,rhlB,rhlI, andrhlR,defective in rhamnolipids production, had significantly reduced levels of SRB biofilm dispersal. Corroborating these results, purified rhamnolipids dispersed SRB biofilms, and rhamnolipids were detected in theP. aeruginosasupernatants. Hence,P. aeruginosasupernatants disperse SRB biofilms via rhamnolipids. In addition, the supernatants ofP. aeruginosadispersed the SRB biofilms more readily than protease in M9 glucose minimum medium and were also effective against biofilms ofEscherichia coliandBacillus subtilis.

Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria

2016 ◽  
Vol 73 (9) ◽  
pp. 2039-2051 ◽  
Author(s):  
Yongchao Li ◽  
Xiaoxian Hu ◽  
Bozhi Ren
Keyword(s):  
Iron Oxide ◽  
Mine Drainage ◽  
Low Cost ◽  
Sulfate Reducing Bacteria ◽  
Growth Conditions ◽  
Iron Corrosion ◽  
Sulfate Reducing ◽  
Iron Oxidizing Bacteria ◽  
Challenges And Opportunities ◽  
Reducing Bacteria

The present article summarizes antimony mine distribution, antimony mine drainage generation and environmental impacts, and critically analyses the remediation approach with special emphasis on iron oxidizing bacteria and sulfate reducing bacteria. Most recent research focuses on readily available low-cost adsorbents, such as minerals, wastes, and biosorbents. It is found that iron oxides prepared by chemical methods present superior adsorption ability for Sb(III) and Sb(V). However, this process is more costly and iron oxide activity can be inhibited by plenty of sulfate in antimony mine drainage. In the presence of sulfate reducing bacteria, sulfate can be reduced to sulfide and form Sb2S3 precipitates. However, dissolved oxygen and lack of nutrient source in antimony mine drainage inhibit sulfate reducing bacteria activity. Biogenetic iron oxide minerals from iron corrosion by iron-oxidizing bacteria may prove promising for antimony adsorption, while the micro-environment generated from iron corrosion by iron oxidizing bacteria may provide better growth conditions for symbiotic sulfate reducing bacteria. Finally, based on biogenetic iron oxide adsorption and sulfate reducing bacteria followed by precipitation, the paper suggests an alternative treatment for antimony mine drainage that deserves exploration.

Specificity of Lectins Labeled with Colloidal Gold to the Exopolymeric Matrix Carbohydrates of the Sulfate-Reducing Bacteria Biofilm Formed on Steel

2020 ◽  
Vol 82 (5) ◽  
pp. 11-20
Author(s):  
D.R. Abdulina ◽  
◽  
L.M. Purish ◽  
G.O. Iutynska ◽  
◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Colloidal Gold ◽  
Steel Surface ◽  
Lectin Binding ◽  
Sulfate Reducing Bacteria ◽  
Gold Particles ◽  
Sulfate Reducing ◽  
Transmission Electron ◽  
Reducing Bacteria

The studies of the carbohydrate composition of the sulfate-reducing bacteria (SRB) biofilms formed on the steel surface, which are a factor of microbial corrosion, are significant. Since exopolymers synthesized by bacteria could activate corrosive processes. The aim of the study was to investigate the specificity of commercial lectins, labeled with colloidal gold to carbohydrates in the biofilm exopolymeric matrix produced by the corrosive-relevant SRB strains from man-caused ecotopes. Methods. Microbiological methods (obtaining of the SRB biofilms during cultivation in liquid Postgate B media under microaerophilic conditions), biochemical methods (lectin-binding analysis of 10 commercial lectins, labeled with colloidal gold), transmission electron microscopy using JEM-1400 JEOL. Results. It was shown using transmission electron microscopy that the binding of lectins with carbohydrates in the biofilm of the studied SRB strains occurred directly in the exopolymerіс matrix, as well as on the surfaces of bacterial cells, as seen by the presence of colloidal gold particles. For detection of the neutral carbohydrates (D-glucose and D-mannose) in the biofilm of almost all studied bacterial strains PSA lectin was the most specific. This lectin binding in biofilms of Desulfotomaculum sp. К1/3 and Desulfovibrio sp. 10 strains was higher in 90.8% and 94.4%, respectively, then for ConA lectin. The presence of fucose in the SRB biofilms was detected using LABA lectin, that showed specificity to the biofilm EPS of all the studied strains. LBA lectin was the most specific to N-аcetyl-D-galactosamine for determination of amino sugars in the biofilm. The amount of this lectin binding in D. vulgaris DSM644 biofilm was 30.3, 10.1 and 9.3 times higher than SBA, SNA and PNA lectins, respectively. STA, LVA and WGA lectins were used to detect the N-acetyl-Dglucosamine and sialic acid in the biofilm. WGA lectin showed specificity to N-acetyl-D-glucosamine in the biofilm of all the studied SRB; maximum number of bounded colloidal gold particles (175 particles/μm2) was found in the Desulfotomaculum sp. TC3 biofilm. STA lectin was interacted most actively with N-acetyl-D-glucosamine in Desulfotomaculum sp. TC3 and Desulfomicrobium sp. TC4 biofilms. The number of bounded colloidal gold particles was in 9.2 and 7.4 times higher, respectively, than using LVA lectin. The lowest binding of colloidal gold particles was observed for LVA lectin. Conclusions. It was identified the individual specificity of the 10 commercial lectins to the carbohydrates of biofilm matrix on the steel surface, produced by SRB. It was estimated that lectins with identical carbohydrates specificity had variation in binding to the biofilm carbohydrates of different SRB strains. Establishing of the lectin range selected for each culture lead to the reduction of the scope of studies and labor time in the researching of the peculiarities of exopolymeric matrix composition of biofilms formed by corrosiverelevant SRB.

The influence of potassium dichromate on dissimilatory reduction of sulfate and nitrate ions by bacteria Desulfovibrio sp.

2017 ◽  
Vol 28 (1-2) ◽  
pp. 84-95
Author(s):  
O. M. Moroz ◽  
S. O. Hnatush ◽  
Ch. I. Bohoslavets ◽  
T. M. Hrytsun’ ◽  
B. M. Borsukevych
Keyword(s):  
Electron Acceptor ◽  
Potassium Dichromate ◽  
Anaerobic Respiration ◽  
Sulfate Reducing Bacteria ◽  
Negative Influence ◽  
Electron Acceptors ◽  
Metal Compounds ◽  
Nitrate Ions ◽  
Sulfate Reducing ◽  
Reducing Bacteria

Sulfate reducing bacteria, capable to reductive transformation of different nature pollutants, used in biotechnologies of purification of sewage, contaminated by carbon, sulfur, nitrogen and metal compounds. H2S formed by them sediment metals to form of insoluble sulfides. Number of metals can be used by these microorganisms as electron acceptors during anaerobic respiration. Because under the influence of metal compounds observed slowing of bacteria metabolism, selection isolated from technologically modified ecotops resistant to pollutions strains is important task to create a new biotechnologies of purification. That’s why the purpose of this work was to study the influence of potassium dichromate, present in medium, on reduction of sulfate and nitrate ions by sulfate reducing bacteria Desulfovibrio desulfuricans IMV K-6, Desulfovibrio sp. Yav-6 and Desulfovibrio sp. Yav-8, isolated from Yavorivske Lake, to estimate the efficiency of possible usage of these bacteria in technologies of complex purification of environment from dangerous pollutants. Bacteria were cultivated in modified Kravtsov-Sorokin medium without SO42- and FeCl2×4H2O for 10 days. To study the influence of K2Cr2O7 on usage by bacteria SO42- or NO3- cells were seeded to media with Na2SO4×10H2O or NaNO3 and K2Cr2O7 at concentrations of 1.74 mM for total content of electron acceptors in medium 3.47 mM (concentration of SO42- in medium of standard composition). Cells were also seeded to media with 3.47 mM Na2SO4×10H2O, NaNO3 or K2Cr2O7 to investigate their growth in media with SO42-, NO3- or Cr2O72- as sole electron acceptor (control). Biomass was determined by turbidymetric method, content of sulfate, nitrate, dichromate, chromium (III) ions, hydrogen sulfide or ammonia ions in cultural liquid – by spectrophotometric method. It was found that K2Cr2O7 inhibits growth (2.2 and 1.3 times) and level of reduction by bacteria sulfate or nitrate ions (4.2 and 3.0 times, respectively) at simultaneous addition into cultivation medium of 1.74 mM SO42- or NO3- and 1.74 mM Cr2O72-, compared with growth and level of reduction of sulfate or nitrate ions in medium only with SO42- or NO3- as sole electron acceptor. Revealed that during cultivation of bacteria in presence of equimolar amount of SO42- or NO3- and Cr2O72-, last used by bacteria faster, content of Cr3+ during whole period of bacteria cultivation exceeded content H2S or NH4+. K2Cr2O7 in medium has most negative influence on dissimilatory reduction by bacteria SO42- than NO3-, since level of nitrate ions reduction by cells in medium with NO3- and Cr2O72- was a half times higher than level of sulfate ions reduction by it in medium with SO42- and Cr2O72-. The ability of bacteria Desulfovibrio sp. to priority reduction of Cr2O72- and after their exhaustion − NO3- and SO42- in the processes of anaerobic respiration can be used in technologies of complex purification of environment from toxic compounds.

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