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

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.

scholarly journals Growth of an anaerobic sulfate-reducing bacterium sustained by oxygen respiratory energy conservation after O2-driven experimental evolution

2018 ◽  
Vol 21 (1) ◽  
pp. 360-373 ◽  
Author(s):  
Marine Schoeffler ◽  
Anne-Laure Gaudin ◽  
Fanny Ramel ◽  
Odile Valette ◽  
Yann Denis ◽  
...  
Keyword(s):  
Energy Conservation ◽  
Experimental Evolution ◽  
Sulfate Reducing

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.

Habits, hardware, and energy conservation.

1981 ◽  
Vol 36 (4) ◽  
pp. 426-428 ◽  
Author(s):  
Paul C. Stern ◽  
Gerald T. Gardner
Keyword(s):  
Energy Conservation
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