Open AccessProduction of Megacins C and Cx: Presumptive Evidence of Extrachromosomal Control
Author(s) -
Helen D. Donoghue
Publication year - 1977
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.11.1.34
Subject(s) - ethidium bromide , reversion , bacillus megaterium , biology , extrachromosomal dna , growth rate , strain (injury) , microbiology and biotechnology , plasmid , bacteria , genetics , gene , dna , phenotype , geometry , mathematics , anatomy
Exposure of growing cultures ofBacillus 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°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 byB. megaterium 337, up to 14%. Growth at 43°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.