SOME PHYSIOLOGICAL ASPECTS OF MUTANTS OF ESCHERICHIA COLI RESISTANT TO GAMMA IRRADIATION

Abstract

The gamma irradiation resistant mutants of Escherichia coli were indole negative. They did not produce mucoid or slime material in Endo"s agar. A marked variation was noted in the rates of growth of the resistant mutants under shaking and stationary conditions of culture. The mode and rate of utilization of specific carbohydrate substrates by a strain highly resistant to gamma irradiation (12γ) differed from that of the parent (P) strain. The 12γ resting cell suspensions exhibited no respiration on lactose, but substantial activity on glucose and succinic acid. The DNA and RNA contents per parent and 12γ cell were the same. The possible sites of inactivation are discussed.