Cold-sensitive mutant with defective growth at 5 °C from a psychrotrophic bacterium
| Autor: | W. E. Inniss, W. D. Murray |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Adenosine Triphosphatases
Methylnitronitrosoguanidine biology Immunology Mutant Cold sensitive Bacillus Bacillus psychrophilus General Medicine biology.organism_classification Applied Microbiology and Biotechnology Microbiology Oxidative Phosphorylation Culture Media Cold Temperature Penicillin Oxygen Consumption Biochemistry Mutation Genetics medicine Citrates Molecular Biology Bacteria medicine.drug |
| Zdroj: | Canadian Journal of Microbiology. 26:1-6 |
| ISSN: | 1480-3275 0008-4166 |
| DOI: | 10.1139/m80-001 |
| Popis: | A cold-sensitive (CS) mutant of the psychrotroph, Bacillus psychrophilus, was obtained by N-methyl-N'-nitro-N-nitrosoguanidine mutagenization and penicillin counterselection. In the presence of citrate, the wild-type grew well at both 5 and 20 degrees C whereas the CS mutant grew well at 20 degrees C (the permissive temperature) but, at 5 degrees C (the restrictive temperature), grew at a reduced rate for two to three generations followed by a complete plateau in growth. Upon return of the CS mutant to 20 degrees C, after a delay of about 40 h, growth resumed at the appropriate rate. The CS mutant exhibited growth rates similar to parental rates on a wide variety of carbon sources at 5 degrees C, but when Krebs cycle intermediates were used as substrates and in the presence of an equimolar amount of citrate, the typical cold-sensitive growth pattern occurred. Comparison of oxidative phosphorylation in the parent and CS mutant indicated that no phosphorylation occurred at 5 degrees C in the CS mutant during the plateau in growth. Examination of the effect of temperature on ATPase activity showed that at 5 degrees C the specific activity of ATPase isolated from the CS mutant grows at 5 degrees C was 15-fold less than the ATPases isolated from wild-type cells grown at either 5 or 20 degrees C and 10.5-fold lower than ATPase from CS mutant cells grown at 20 degrees C. The large reduction in CS mutant ATPase activity at 5 degrees C appears to be at least partly due to an effect on synthesis since citrate did not inhibit preformed ATPase. |
| Databáze: | OpenAIRE |
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