scholarly journals Stratified Microbial Structure and Activity in Sulfide- and Methane-Producing Anaerobic Sewer Biofilms

2014 ◽  
Vol 80 (22) ◽  
pp. 7042-7052 ◽  
Author(s):  
Jing Sun ◽  
Shihu Hu ◽  
Keshab Raj Sharma ◽  
Bing-Jie Ni ◽  
Zhiguo Yuan
Keyword(s):  
Surface Layer ◽  
Methanogenic Archaea ◽  
Molecular Techniques ◽  
Content Type ◽  
Sulfate Reducing ◽  
Biofilm Model ◽  
Reducing Bacteria ◽  
Microelectrode Measurements ◽  
Good Agreement

ABSTRACTSimultaneous production of sulfide and methane by anaerobic sewer biofilms has recently been observed, suggesting that sulfate-reducing bacteria (SRB) and methanogenic archaea (MA), microorganisms known to compete for the same substrates, can coexist in this environment. This study investigated the community structures and activities of SRB and MA in anaerobic sewer biofilms (average thickness of 800 μm) using a combination of microelectrode measurements, molecular techniques, and mathematical modeling. It was seen that sulfide was mainly produced in the outer layer of the biofilm, between the depths of 0 and 300 μm, which is in good agreement with the distribution of SRB population as revealed by cryosection-fluorescencein situhybridization (FISH). SRB had a higher relative abundance of 20% on the surface layer, which decreased gradually to below 3% at a depth of 400 μm. In contrast, MA mainly inhabited the inner layer of the biofilm. Their relative abundances increased from 10% to 75% at depths of 200 μm and 700 μm, respectively, from the biofilm surface layer. High-throughput pyrosequencing of 16S rRNA amplicons showed that SRB in the biofilm were mainly affiliated with five genera,Desulfobulbus,Desulfomicrobium,Desulfovibrio,Desulfatiferula, andDesulforegula, while about 90% of the MA population belonged to the genusMethanosaeta. The spatial organizations of SRB and MA revealed by pyrosequencing were consistent with the FISH results. A biofilm model was constructed to simulate the SRB and MA distributions in the anaerobic sewer biofilm. The good fit between model predictions and the experimental data indicate that the coexistence and spatial structure of SRB and MA in the biofilm resulted from the microbial types and their metabolic transformations and interactions with substrates.

Alternating wet-dry cycles rather than sulfate fertilization control pathways of methanogenesis and methane turnover in rice straw-amended paddy soil

2021 ◽  
Author(s):  
Qiong Liu ◽  
Marco Romani ◽  
Jiajia Wang ◽  
Britta Planer-Friedrich ◽  
Johanna Pausch ◽  
...  
Keyword(s):  
Rice Straw ◽  
Management Practices ◽  
Methanogenic Archaea ◽  
Paddy Soils ◽  
Effective Management ◽  
Flowering Stage ◽  
Sulfate Reducing ◽  
Hydrogenotrophic Methanogenesis ◽  
Reducing Bacteria

<p>Alternate wet-drying (AWD) and sulfate fertilization have been considered as effective management practices for lowering CH<sub>4</sub> emissions from paddy soils. However, the effects of management practices on in situ belowground CH<sub>4</sub> turnover (production and oxidation) are not yet fully understood. Here, soil CO<sub>2</sub> and CH<sub>4</sub> concentrations and their C isotope compositions were measured at three rice growing stages in straw-amended paddy soils with and without sulfate fertilization under continuously flooded conditions and two wet-dry-cycles. CH<sub>4</sub> concentration reached 51.0 mg C L<sup>-1</sup> at flowering stage under flooded conditions, while it decreased to 0.04 mg C L<sup>-1</sup> under AWD. Relative enrichment of δ<sup>13</sup>C in CH<sub>4</sub> and depletion of δ<sup>13</sup>C in CO<sub>2</sub> under AWD indicated CH<sub>4</sub> oxidation. Sulfate addition had no significant effect on CH<sub>4</sub> concentration. The ample substrate supply might have prevented sulfate-reducing bacteria from out-competing methanogenic archaea and could therefore explain the absence of a fall in CH<sub>4</sub> production. The δ<sup>13</sup>C-CO<sub>2</sub> enrichment over time (7 ‰ and 5‰ with and without sulfate fertilizer, respectively) under flooded conditions likely indicates an increasing contribution of hydrogenotrophic methanogenesis to CH<sub>4</sub> production with ongoing rice growth. Overall, the results showed that AWD could more efficiently reduce CH<sub>4</sub> production than sulfate fertilization in rice-straw-amended paddy soils.</p><p> </p>

scholarly journals Microbial Ecology of Anaerobic Digesters: The Key Players of Anaerobiosis

2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Fayyaz Ali Shah ◽  
Qaisar Mahmood ◽  
Mohammad Maroof Shah ◽  
Arshid Pervez ◽  
Saeed Ahmad Asad
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Methanogenic Bacteria ◽  
Molecular Techniques ◽  
Anaerobic Digesters ◽  
Sulfate Reducing ◽  
Anaerobic Microorganisms ◽  
Gradient Gel Electrophoresis ◽  
Reducing Bacteria ◽  
Complex Organic

Anaerobic digestion is the method of wastes treatment aimed at a reduction of their hazardous effects on the biosphere. The mutualistic behavior of various anaerobic microorganisms results in the decomposition of complex organic substances into simple, chemically stabilized compounds, mainly methane andCO2. The conversions of complex organic compounds toCH4andCO2are possible due to the cooperation of four different groups of microorganisms, that is, fermentative, syntrophic, acetogenic, and methanogenic bacteria. Microbes adopt various pathways to evade from the unfavorable conditions in the anaerobic digester like competition between sulfate reducing bacteria (SRB) and methane forming bacteria for the same substrate.Methanosarcinaare able to use both acetoclastic and hydrogenotrophic pathways for methane production. This review highlights the cellulosic microorganisms, structure of cellulose, inoculum to substrate ratio, and source of inoculum and its effect on methanogenesis. The molecular techniques such as DGGE (denaturing gradient gel electrophoresis) utilized for dynamic changes in microbial communities and FISH (fluorescentin situhybridization) that deal with taxonomy and interaction and distribution of tropic groups used are also discussed.

scholarly journals Integrative analysis of <i>Geobacter</i> spp. and sulfate-reducing bacteria during uranium bioremediation

2012 ◽  
Vol 9 (3) ◽  
pp. 1033-1040 ◽  
Author(s):  
M. Barlett ◽  
K. Zhuang ◽  
R. Mahadevan ◽  
D. Lovley
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Field Trials ◽  
Second Phase ◽  
Sulfate Reducing ◽  
Organic Electron ◽  
Poor Understanding ◽  
Key Factor ◽  
Reducing Bacteria ◽  
The Impact

Abstract. Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

Microbial ecology of sulfate-reducing bacteria in wastewater biofilms analyzed by microelectrodes and fish (fluorescent in situ hybridization) technique

1999 ◽  
Vol 39 (7) ◽  
pp. 41-47 ◽  
Author(s):  
Satoshi Okabe ◽  
Hisashi Satoh ◽  
Tsukasa Itoh ◽  
Yoshimasa Watanabe
Keyword(s):  
In Situ Hybridization ◽  
Sulfate Reduction ◽  
Sulfate Reducing Bacteria ◽  
Hybridization Technique ◽  
Concentration Profiles ◽  
Reduction Zone ◽  
Sulfate Reducing ◽  
Reducing Bacteria ◽  
Culture Dependent

The vertical distribution of sulfate-reducing bacteria (SRB) in microaerophilic wastewater biofilms grown on fully submerged rotating disk reactors (RDR) was determined by the conventional culture-dependent MPN method and in situ hybridization of fluorescently-labelled 16S rRNA-targeted oligonucleotide probes for SRB in parallel. Chemical concentration profiles within the biofilm were also measured using microelectrodes for O2, S2-, NO3- and pH. In situ hybridization revealed that the SRB probe-stained cells were distributed throughout the biofilm even in the oxic surface zone in all states from single scattered cells to clustered cells. The higher fluorescence intensity and abundance of SRB probe-stained cells were found in the middle part of the biofilm. This result corresponded well with O2 and H2S concentration profiles measured by microelectrodes, showing sulfate reduction was restricted to a narrow anaerobic zone located about 500 μm below the biofilm surface. Results of the MPN and potential sulfate reducing activity (culture-dependent approaches) indicated a similar distribution of cultivable SRB in the biofilm. The majority of the general SRB probe-stained cells were hybridized with SRB 660 probe, suggesting that one important member of the SRB in the wastewater biofilm could be the genus Desulfobulbus. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from O2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium.

scholarly journals Physiology, Biochemistry, and Applications of F420- and Fo-Dependent Redox Reactions

2016 ◽  
Vol 80 (2) ◽  
pp. 451-493 ◽  
Author(s):  
Chris Greening ◽  
F. Hafna Ahmed ◽  
A. Elaaf Mohamed ◽  
Brendon M. Lee ◽  
Gunjan Pandey ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Methanogenic Archaea ◽  
Content Type ◽  
Sulfate Reducing ◽  
Single Function ◽  
Wide Range ◽  
Domains Of Life ◽  
Photochemical Properties ◽  
Endogenous Metabolites ◽  
Dependent Processes

SUMMARY5-Deazaflavin cofactors enhance the metabolic flexibility of microorganisms by catalyzing a wide range of challenging enzymatic redox reactions. While structurally similar to riboflavin, 5-deazaflavins have distinctive and biologically useful electrochemical and photochemical properties as a result of the substitution of N-5 of the isoalloxazine ring for a carbon. 8-Hydroxy-5-deazaflavin (Fo) appears to be used for a single function: as a light-harvesting chromophore for DNA photolyases across the three domains of life. In contrast, its oligoglutamyl derivative F420is a taxonomically restricted but functionally versatile cofactor that facilitates many low-potential two-electron redox reactions. It serves as an essential catabolic cofactor in methanogenic, sulfate-reducing, and likely methanotrophic archaea. It also transforms a wide range of exogenous substrates and endogenous metabolites in aerobic actinobacteria, for example mycobacteria and streptomycetes. In this review, we discuss the physiological roles of F420in microorganisms and the biochemistry of the various oxidoreductases that mediate these roles. Particular focus is placed on the central roles of F420in methanogenic archaea in processes such as substrate oxidation, C1pathways, respiration, and oxygen detoxification. We also describe how two F420-dependent oxidoreductase superfamilies mediate many environmentally and medically important reactions in bacteria, including biosynthesis of tetracycline and pyrrolobenzodiazepine antibiotics by streptomycetes, activation of the prodrugs pretomanid and delamanid byMycobacterium tuberculosis, and degradation of environmental contaminants such as picrate, aflatoxin, and malachite green. The biosynthesis pathways of Foand F420are also detailed. We conclude by considering opportunities to exploit deazaflavin-dependent processes in tuberculosis treatment, methane mitigation, bioremediation, and industrial biocatalysis.

Zwitterionic molecule layer for inhibiting microbial corrosion of copper alloy

2018 ◽  
Vol 65 (1) ◽  
pp. 46-52
Author(s):  
Fengling Xu ◽  
Zhenghui Qiu ◽  
Ri Qiu ◽  
Jiadong Yang ◽  
Cunguo Lin
Keyword(s):  
Electrochemical Impedance ◽  
Chemical Vapor ◽  
Attenuated Total Reflectance ◽  
Microbial Corrosion ◽  
Content Type ◽  
Sulfate Reducing ◽  
Angle Measurements ◽  
Static Contact ◽  
Contact Angle Measurements ◽  
Reducing Bacteria

Purpose For mitigating biocorrosion induced by sulfate-reducing bacteria (SRB) in seawater, the zwitterionic molecule layer (ZML) of poly (sulfobetaine methacrylate) is grafted onto B10 surface by chemical vapor deposition and surface-initiated atom transfer radical polymerization. Design/methodology/approach Energy-dispersive spectroscopy-attenuated total reflectance Fourier transform infrared spectroscopy and static contact angle measurements are used to characterize the as-formed layer. Findings After surface modification, B10 can significantly reduce SRB adhesion, demonstrating the good antifouling property. Further, the biocorrosion inhibition is investigated by potentiodynamic polarization and electrochemical impedance spectroscopy, indicating that ZML exhibits high resistance to biocorrosion with inhibition efficiency of approximately 90 per cent. Originality/value ZML performs a dual feature, i.e. antifouling film and corrosion inhibitor, for the biocorrosion inhibition.

Improvement of MIC Behavior of Ship Plate Steel with LaCl3-Zn Epoxy Coating

2011 ◽  
Vol 488-489 ◽  
pp. 254-257
Author(s):  
Qing Fen Li ◽  
Jun Wang ◽  
Yu Dong Fu ◽  
Chun Hui Li
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Potential ◽  
Steel Specimen ◽  
Epoxy Coating ◽  
Plate Steel ◽  
Sulfate Reducing ◽  
Corrosion Resistance Property ◽  
Reducing Bacteria ◽  
Better Than ◽  
Good Agreement

The MIC behavior of the ship plate steel specimen with LaCl3-Zn epoxy coating in the sulfate-reducing bacteria (SRB) solution was investigated in this paper. The variation of corrosion potential over time of different specimens in SRB solution show that the corrosion potential of the specimen with LaCl3-Zn epoxy coating was obviously higher than the Zn-epoxy coating, suggesting that the LaCl3-Zn epoxy coating may offer better protection. The variations of lgflg |Z|=4.5 and fhwith time show that the property of anti-infiltration and corrosion resistance of LaCl3-Zn coating is much better than the ones of Zn-epoxy coating. Results also show that more sulfides and corrosion products of LaCl3-Zn epoxy coating were produced which increased the shielding property of the coating. The experimental results of XRD and SEM are in good agreement with the ones of Ecorr,and EIS, etc. They all show that the LaCl3-Zn epoxy coating exhibits more favorable corrosion resistance property than the Zn-epoxy coating. It is obvious that coating the ship plate steel with LaCl3-Zn epoxy is an effective and promising method against the attack of SRB in marine environment.

Phage therapy of corrosion-producing bacterium Stenotrophomonas maltophilia using isolated lytic bacteriophages

2017 ◽  
Vol 64 (6) ◽  
pp. 607-612 ◽  
Author(s):  
Arezoo Pedramfar ◽  
Keivan Beheshti Maal ◽  
Sayed Hossein Mirdamadian
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Culture Medium ◽  
Phage Therapy ◽  
Isolation And Identification ◽  
Content Type ◽  
Sulfate Reducing ◽  
Transmission Electron ◽  
Reducing Bacteria ◽  
Pipeline Corrosion ◽  
Selective Culture Medium

Purpose Corrosion-producing microorganisms have different physiology and include sulfate-reducing bacteria, iron oxidizers and magnesium oxidizers. Biocorrosion has been seen in various industries, especially the petrochemicals and oil industries. One proposal to solve this problem is the use of bacteriophages to treat the bacteria-caused corrosion. The aims of this study were isolation and identification of corrosion-producing bacteria from petroleum pipeline corrosion as well as finding their specific bacteriophages for phage therapy purposes. Design/methodology/approach The sample pipes with the corrosion were obtained from the Gandomkar petroleum pipeline station, Chaharmahal and Bakhtiari, Iran. For screening the corrosion-producing bacteria, the rusted pipe samples were cultured in a selective culture medium, manganese agar. The purified individual colonies were subjected to molecular examinations. For isolating bacteriophages from silversmithing workshops wastewater in Isfahan, whole plate titration methods and transmission electron microscopy were used to isolate and detect phages. Findings The cultivation of corrosion-based material on manganese agar after 18 hours incubation at 30°C resulted in the isolation of cream-colored colonies. The microscopic examinations showed Gram-negative coccobacilli. Based on molecular examinations, the isolated bacteria were identified as Stenotrophomonas maltophilia strain PBM-IAUF-2 with Genebank accession number of KU145278.1. The found bacteriophage was related to the Siphoviridae family of phages. Originality/value This paper is the first report of isolation and identification of corrosion-producing bacteria and its specific lytic phages from Gandomkar petroleum pipeline station, Chaharmahal and Bakhtiari, Iran. The biological procedures for preventing the microbial corrosion could be an asset and considered as a potential in the petroleum and industrial microbiology. Phage therapy is considered as one of the economical methods for reducing the biocorrosion.

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