title: Plasmid-influenced changes in Mycobacterium avium catalase activity.
abstract: A virulent Mycobacterium avium strain, LR25, which carries three plasmids (18, 28, and 165 kilobases) and grows at 43 degrees C was compared with its plasmid-free, avirulent segregant, strain LR163, to identify the basis for the latter's inability to grow at 43 degrees C. The failure of mid-log-phase cultures of strain LR163 to grow at 43 degrees C was dependent on the presence of high levels of culture aeration. In addition, highly aerated cultures of strain LR163 failed to grow at 37 degrees C. Mid-log-phase cultures of strain LR163 had 30% of the catalase activity of strain LR25 and were more hydrogen peroxide (0.08%, wt/vol) susceptible. Catalase activity of strain LR25 was higher in cultures grown with high aeration than in those grown with almost no aeration. These data support the contention that plasmid-encoded genes influence M. avium catalase activity.
authors.affiliation: Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
authors.forename: M L
authors.initials: ML
authors.lastname: Pethel
authors.forename: J O
authors.initials: JO
authors.lastname: Falkinham
mesh_terms: D000332:Aerobiosis; D002374:Catalase / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009162:Mycobacterium avium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010957:Plasmids; D013696:Temperature
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase