Amongst the nitrogen sources, tryptone and yeast extract at 0.5% and 0.15% level, respectively, caused maximum enzyme production by Bacillus stearothermophilus RM-67. Addition of sodium chloride (0.5%) to the basal medium enhanced the enzyme production by 63%. Various sugars incorporated into the standardized basal medium proved inhibitory to enzyme elaboration. Maximum enzyme production was observed in the early decline growth phase of the organism in tryptone-yeast extract-salt medium (pH 6.5) when inoculated at 4% level and incubated on a rotary shaker at 55°C for 8 h and subsequently at 45°C up to 24 h.
1Present address: Dept. of Cell Physiology, Institute of Microbiology, Czechoslovak Academy of Science, Videnska-1083, Prague 4, Czechoslovakia.