Enzyme and Microbial Technology, Vol.39, No.6, 1279-1285, 2006
Regulation of CCR in the gamma-CGTase production from Bacillus macorous by the specific cell growth rate control
Malto-oligosaccharides were products of the degradation of corn starch in the gamma-CGTase production by Bacillus macorous WSH02-06, and catabolically repressed the synthesis of gamma-CGTase. The investigation of the enzyme production at different agitation speeds, pH-stat values and temperatures revealed that the amount of malto-oligosaccharides accumulated in cultivation was in direct connection with the specific cell growth rate. When the maximal specific growth rate was higher than 0.2 h(-1), the gamma-CGTase yield decreased. Thus, the nutrients were supplied in the exponential feeding mode for limiting the maximal specific growth rate and the gamma-CGTase yield was promoted to the highest value of 2565 U mL(-1) that was 6.88-fold higher than that achieved in the batch fermentation. (c) 2006 Elsevier Inc. All rights reserved.