Response of a strict anaerobe to oxygen:: survival strategies in Desulfovibrio gigas

被引:54
作者
Fareleira, P
Santos, BS
António, C
Moradas-Ferreira, P
LeGall, J
Xavier, AV
Santos, H
机构
[1] Univ Nova Lisboa, Inst Tecnol Quim & Biol, P-2780156 Oeiras, Portugal
[2] Inst Nacl Invest Agraria, Estacao Agron Nacl, P-2780156 Oeiras, Portugal
[3] Univ Porto, Inst Biol Mol & Celular, P-4150 Oporto, Portugal
[4] Univ Georgia, Dept Biochem & Mol Biol, Athens, GA 30602 USA
来源
MICROBIOLOGY-SGM | 2003年 / 149卷
关键词
D O I
10.1099/mic.0.26155-0
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
The biochemical response to oxygen of the strictly anaerobic sulfate-reducing bacterium Desulfovibrio gigas was studied with the goal of elucidating survival strategies in oxic environments. Cultures of D. gigas on medium containing lactate and sulfate were exposed to oxygen (concentration 5-120 muM). Growth was fully inhibited by oxygen, but the cultures resumed growth as soon as they were shifted back to anoxic conditions. Following 24 h exposure to oxygen the growth rate was as high as 70% of the growth rates observed before oxygenation. Catalase levels and activity were enhanced by exposure to oxygen whereas superoxide-scavenging and glutathione reductase activities were not affected. The general pattern of cellular proteins as analysed by two-dimensional electrophoresis was altered in the presence of oxygen, the levels of approximately 12% of the detected proteins being markedly increased. Among the induced proteins, a homologue of a 60 kDa eukaryotic heat-shock protein (Hsp60) was identified by immunoassay analysis. In the absence of external substrates, the steady-state levels of nucleoside triphosphates detected by in vivo P-31-NMR under saturating concentrations of oxygen were 20% higher than under anoxic conditions. The higher energy levels developed under oxygen correlated with a lower rate of substrate (glycogen) mobilization, but no experimental evidence for a contribution from oxidative phosphorylation was found. The hypothesis that oxygen interferes with ATP dissipation processes is discussed.
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页码:1513 / 1522
页数:10
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