1975 Volume 41 Issue 1 Pages 40-48
The production of antibacterial agents (AAs) by isolates of Erwinia carotovora, the properties and their activity spectra were studied. The bacterial cell inductively produced the AA, when irradiated with UV or treated with mitomycin C at their early exponential growth phase, corresponding to the lysis of bacterial cells observed during 3-5hrs of culture after the treatment. The AAs obtained from 5hrs cultures of each isolate after UV irradiation differed from each other in their activities. In the case of one isolate, however, the activity did not vary with the difference in the induction method. All of the 17 isolates were found to have the ability to produce the agents, which were classified tentatively into 4 groups according to the similarity of their activity spectrum. The agent produced by each isolate indicated that it cannot be reproduced in the cell of each indicator. The activity of AA was found to be maintained for at least 20 days at 4C; it was retained in dialized solution but was lost by heat treatment; and it was found in the precipitate obtained by salting out the lysate. UV absorption spectra of the partially purified preparation exhibited the highest absorption at 275nm and the lowest at 260nm. The AAs appeared to be protein characterized by a large molecule. It was concluded that AAs are a kind of bacteriocin.