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[Antibiotic action on Bacillus polymyxa 153 enzymatic activity]
Antibiotiki
|February 1, 1980
Summary
Antibiotics differentially affect enzymes in bacterial cell extracts. Polymyxins specifically inhibit succinate and malate dehydrogenase, while other antibiotics impact pyruvate and alpha-ketoglutarate dehydrogenase complexes.
Area of Science:
- Microbiology
- Biochemistry
- Enzymology
Background:
- Bacillus polymyxa produces polymyxin B, a crucial antibiotic.
- Understanding antibiotic interactions with bacterial metabolic enzymes is vital.
Purpose of the Study:
- To investigate the impact of various antibiotics on key enzymes involved in cellular respiration.
- To determine the specific enzyme targets of polymyxins and other antibiotics in Bac. polymyxa.
Main Methods:
- Enzyme activity assays were performed on cell extracts of Bac. polymyxa 153.
- The effects of different antibiotics, including polymyxins M and B, novobiocin, ristomycin, and nistatin, were assessed.
Main Results:
- Enzyme sensitivity to antibiotics varied significantly.
- Succinate dehydrogenase showed specific sensitivity to polymyxins M and B.
- Malate dehydrogenase was sensitive to polymyxin B.
- Pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase complexes were inhibited by polymyxins, novobiocin, ristomycin, and nistatin.
- NADP-dependent isocitrate dehydrogenase activity remained unaffected by any tested antibiotic.
Conclusions:
- Antibiotics exhibit distinct inhibitory patterns against bacterial metabolic enzymes.
- Polymyxins M and B possess specific inhibitory effects on succinate and malate dehydrogenases.
- The study highlights the differential susceptibility of enzymes within the pyruvate dehydrogenase and tricarboxylic acid cycle pathways to various antibiotics.