Aerobic respiration in sulfate-reducing bacteria*

Abstract

Cultures of Disulfovibrio desulfuricans strain CSN (incubated in a sulfide‐ and sulfate‐free medium) reduced up to 5 mM O2 with H2 as electron donor. Aerobic respiration was not coupled with growth, but resulted in ATP formation. Washed cells incubated in H2‐saturated phosphate buffer revealed respiration rates of up to 250 nmol O2 min−1 mg protein−1. The uncoupler carbonyl‐cyanide m‐chlorophenylhydrazone (CCCP) stimulated the respiration rate and abolished ATP formation. The terminal oxidase has not yet been identified. Respiration was microaerophilic, insensitive to cyanide and azide, but inhibited after heat treatment of the cells (80°C for 10 min). The ph optimum was at pH 6 with less than 50% activity at pH 4.5 and pH 9. Besides H2, organic eletron donors (formate, ethanol, lactate or pyruvate) and inorganic sulfur compounds (H2S, thiosulfate, sulfite) were used as electron donors for aerobic respiration. Sulfite and thiosulfate were oxidized completely to sulfate. The capability of aerobic respiration was also detected in Desulfovibrio vulgaris, D. sulfidismutans, Desulfobacterium autotrophim, Desulfobulbus propionicus, and Desulfococcus multivorans.

Microbial diversity in biofilms from corroding heating systems

“…Whether the organisms were facultative aerobes is not known, but since the fraction was higher than the fraction able to consume acetate under anaerobic conditions, some may have been obligate aerobes. Some of the anaerobes might also be oxygen-tolerant SRP that can consume oxygen, and probably also organic compounds, under aerobic conditions (Dilling & Cypionka, 1990). The MAR results also revealed presence of SRP in agreement with the FISH results and methanogenic bacteria in the biofilm.…”

Corrosion of mild steel in an alternating oxic and anoxic biofilm system

“…A direct role of oxygen could be a reaction of oxygen with hydrogen atoms accumulated within the deposit, which has been suggested by Uhlig (1971), or oxygen could be consumed by aerobic hydrogen consuming microorganisms. Recently, it has been shown that SRB are able to consume oxygen (Dilling & Cypionka, 1990), and hydrogen can be consumed at very high rates by oxygen respiration (Fitz & Cypionka, 1991). This implicates two possible mechanisms of hydrogen removal by the SRB in alternating oxic/anoxic systems, viz sulfate reduction and aerobic respiration.…”

Lipid Biomarker and Isotopic Study of Community Distribution and Biomarker Preservation in a Laminated Microbial Mat from Shark Bay, Western Australia

“…PSB, for instance, can grow photoautotrophically, photoheterotrophically or as Fe-and/or S-oxidising chemoautotrophs [9]. In addition, although SRB are commonly regarded as obligate anaerobic organisms, specific species can undertake limited aerobic respiration [85] and sulfate reduction has been observed under fully oxic conditions [85,86]. SRB have been detected in oxic waters and sediments [87][88][89], as well as oxygensupersaturated mat layers [90][91][92][93].…”