[Biological properties of a Bacillus brevis 101 mutant].

Some features of the Bacillus brevis 101 mutant producing the antibiotic gramicidin S are described. The mutant is very close to the initial P+-variant of Bacillus brevis var. G-B by cultural, physiological and biochemical characteristics.

[An oligosporogenic mutant of Bacillus brevis].

The treatment of Bacillus brevis var. G-B by chemical mutagens yielded a mutant similar in the major characteristics to the parent strain of the P+-variant, but producing less spores and synthesizing more gramicidin S. The mutant can be stored in the freeze-dried state.

[Role of gramicidin S in the sporulation of the R+ and R- variants of Bacillus brevis var. G.-B].

The effect of gramicidin S added to the cultivation medium on sporulation of the gramicidin S-producing P+ variant and gramicidin S-nonproducing P- variant of Bacillus brevis var. G.-B.

[Effect of gramicidin C on the formation and germination of Bacillus brevis var. GB (P+-variant) spores].

The effect of gramicidin C added to the medium at various periods of cultivation in concentrations of 20, 40 and 100 gamma/ml on sporulation of P+-variant of Bac. brevis var. GB was studied.

[Effect of different factors on the germination of spores in S and P- variants of Bacillus brevis].

The effect of temperature, duration of heating and the presence of L-alanine and L-glutamine in the medium on the spore germination was studied with the S and P- variants of Bacillus brevis which did not contain gramicidin S and with the R and P+ varants obtained on a defined medium with beta-phenyl-beta-alanine, an inhibitor of the biosynthesis of gramicidin S. The experiments were carried out according to the scheme of complete factor experiment. Germination of the spores was found upon their incubation in a defined medium with L-alanine within two hours after their preliminary heating at 80 degrees C during 45 minutes (S variant), at 60 degrees C during 45 minutes (R variant+trace amounts of gramicidin S), at 80 degrees C during 15 minutes (P+ variant/trace amounts of gramicidin S).