Effect of arginine on gramicidin S biosynthesis by Bacillus brevis

Effects of arginine on gramicidin S (GS) biosynthesis were investigated by growing Bacillus brevis ATCC 9999 in a synthetic medium consisting of 10 g fructose, 0.15 g l-proline, 1.3 g l-histidine, 1.3 g l-glutamine, 0.5 g L-methionine, 1 g L-phenylalanine and six mineral salts per liter. Supplement of 3 g/liter L-arginine to the medium, especially at the logarithmic phase of growth, enhanced the cell growth and GS production. Twice supplement of 3 g/liter arginine at the beginning and middle logarithmic phase of growth gave much more GS production than any once supplement, but the soluble GS synthetase extractable by lysozyme digestion was remarkably decreased. However, the decrease of enzyme by arginine seemed to be merely an apparent phenomenon, because GS-synthesizing ability of the cell was strongly enhanced by arginine and the enzyme which was not extracted by lysozyme digestion could efficiently be solubilized by ultrasonic homogenization. In the soluble fraction of cells grown in an arginine-added synthetic medium, no arginine was detected, but a large amount of ornithine was accumulated. When L-ornithine, instead of L-arginine, was added to the synthetic medium, cell growth and GS production was stimulated with increase of its concentration without decrease in the soluble enzyme activity.