STUDIES WITH BACILLUS POLYMYXA: II. BACTERIOPHAGE OF BACILLUS POLYMYXA IN RELATION TO THE 2,3-BUTANEDIOL FERMENTATION

Abstract

A procedure is described that resulted in the isolation of a number of phages against various strains of Bacillus polymyxa. Out of 82 strains tested, 63 were lysed completely and 6 partially. The phages produced plaques that were separated into eight morphological groups. No special relationship between susceptibility to phage and yield of butanediol was noted.Temperature studies indicated that these phages were very sensitive, being inactivated by an exposure of 30 min. at 55 °C. They were shown to be transmitted through the bacterial spore and under these conditions resisted a temperature of 80 °C. for 60 min.Eight out of 50 strains tested were lysogenic.Phage was capable of almost completely stopping the fermentation of wheat mashes by susceptible strains. Certain resistant cultures gave good yields in the presence of active phage. Mixing resistant and susceptible strains resulted in lowered yields; however, a good fermentation was obtained in the presence of phage by combining three resistant strains. Even in the absence of phage, a mixture of five strains was not favourable, probably as a result of antibiotic effects among the individual strains. Secondary cultures differed markedly in nature of growth and spore-producing capacity from primary strains and were, on the whole, poorer diol producers.It was suggested that under ordinary conditions in the factory, proper sterilization of equipment and materials, aseptic technique, and use of well-tested non-lysogenic strains are adequate precautions against this bacterial virus.