A novel thermotolerant methylotrophicBacillus sp. and its potential for use in single-cell protein production.

A thermotolerant methylotrophicBacillus sp. (KISRI TM1A, NCIMB 40040), isolated from the Kuwaiti environment and belonging to the group II spore-forming, bacilli, could not be correlated with any knownBacillus sp. It may, therefore, be a new species. It grew at temperatures from 37° to 58°C from pH 6.5 to 9.0 and on methanol up to 40 g l(-1). It grew well in a chemostat. Its biomass yield coefficient was improved by about 30% by optimization of medium and growth conditions, reaching a maximum of 0.44g g(-1) at 45°C pH 6.8 to 7.0, dilution rate 0.25 h(-1) with methanol at 10 g l(-1). Average crude protein and amino acid content were 84% and 60%, respectively, and maximum productivity attained under laboratory conditions was 5.06 g l(-1)h(-1). It was concluded that this strain has good potential for use in single-cell protein production.