Inhibition of existing denitrification enzyme activity by chloramphenicol.
AUTOR(ES)
Brooks, M H
RESUMO
Chloramphenicol completely inhibited the activity of existing denitrification enzymes in acetylene-block incubations with (i) sediments from a nitrate-contaminated aquifer and (ii) a continuous culture of denitrifying groundwater bacteria. Control flasks with no antibiotic produced significant amounts of nitrous oxide in the same time period. Amendment with chloramphenicol after nitrous oxide production had begun resulted in a significant decrease in the rate of nitrous oxide production. Chloramphenicol also decreased (greater than 50%) the activity of existing denitrification enzymes in pure cultures of Pseudomonas denitrificans that were harvested during log-phase growth and maintained for 2 weeks in a starvation medium lacking electron donor. Short-term time courses of nitrate consumption and nitrous oxide production in the presence of acetylene with P. denitrificans undergoing carbon starvation were performed under optimal conditions designed to mimic denitrification enzyme activity assays used with soils. Time courses were linear for both chloramphenicol and control flasks, and rate estimates for the two treatments were significantly different at the 95% confidence level. Complete or partial inhibition of existing enzyme activity is not consistent with the current understanding of the mode of action of chloramphenicol or current practice, in which the compound is frequently employed to inhibit de novo protein synthesis during the course of microbial activity assays. The results of this study demonstrate that chloramphenicol amendment can inhibit the activity of existing denitrification enzymes and suggest that caution is needed in the design and interpretation of denitrification activity assays in which chloramphenicol is used to prevent new protein synthesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=195666Documentos Relacionados
- Inhibition of protein synthesis and of auxin-induced growth by chloramphenicol.
- Strain-specific difference that affects the inhibition of division of Escherichia coli filaments by chloramphenicol.
- Chloramphenicol Inhibition of Denitrifying Enzyme Activity in Two Agricultural Soils
- Enhancement of leukocyte activity against Escherichia coli after brief exposure to chloramphenicol.
- Emulsan production by Acinetobacter calcoaceticus in the presence of chloramphenicol.