Growth inhibition of Escherichia coli by dichloromethane in cells expressing dichloromethane dehalogenase/glutathione S-transferase

被引:14
作者
Evans, GJ
Ferguson, GP
Booth, IR
Vuilleumier, S
机构
[1] ETH Zurich, Inst Mikrobiol, ETH Zentrum LFV, CH-8092 Zurich, Switzerland
[2] Univ Aberdeen, Inst Med Sci, Dept Mol & Cell Biol, Aberdeen AB25 2ZD, Scotland
来源
MICROBIOLOGY-UK | 2000年 / 146卷
关键词
glutathione; dichloromethane; intracellular pH; chloride; formaldehyde;
D O I
10.1099/00221287-146-11-2967
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
Dichloromethane (DCM) dehalogenase converts DCM to formaldehyde via the formation of glutathione metabolites and generates 2 mol HCI per mol DCM formation or glutathione metabolites and generates 2 mol HCI per mol DCM metabolized. Growth of Escherichia coli expressing DCM dehalogenase was immediately and severely inhibited during conversion of 0.3 mM DCM. Intracellular pH (pH(i)) rapidly decreased and chloride ions were steadily released into the medium. Bacterial growth resumed after completion of DCM conversion and cell viability was unaffected. At 0.6 mM DCM there was no recovery from growth inhibition in liquid culture due to the build-up of inhibitory concentrations of formaldehyde. DCM turnover stimulated potassium efflux from cells, which was suppressed by glucose. The potassium efflux, therefore, did not contribute to growth inhibition. It was concluded that initial growth inhibition results from lowering of the cytoplasmic pH. but severity of growth inhibition was greater than expected for the change in pH(i). Possible contributors to growth inhibition are discussed.
引用
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页码:2967 / 2975
页数:9
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