title: Production of megacins C and Cx: presumptive evidence extrachromosomal control.
abstract: Exposure of growing cultures of Bacillus megaterium C4A(-) to ethidium bromide or an elevated growth temperature was found to eliminate megacin C production. Ethidium bromide resulted in a cure rate of up to 13%. Growth at 43 degrees C gave a cure rate of up to 99%. Megacin C production was lost spontaneously at a rate of 4% or less. There was a greater rate of spontaneous loss of megacin Cx production by B. megaterium 337, up to 14%. Growth at 43 degrees C resulted in a cure rate of up to 24% in this organism. Reversion to the Meg(+) state by cured clones has never been demonstrated. These observations support the hypothesis that production of megacins C and Cx is plasmid mediated. Meg(-) clones adsorbed more megacin than either parent strain and were more susceptible to megacin action.
mesh_terms: D001410:Bacillus megaterium / Q000378:metabolism*; D001430:Bacteriocins / Q000096:biosynthesis*; D004996:Ethidium / Q000494:pharmacology; D008530:Megacins / Q000096:biosynthesis*; D010957:Plasmids / Q000187:drug effects; D013045:Species Specificity; D013696:Temperature
chemical_list: D001430:Bacteriocins; D008530:Megacins; D004996:Ethidium