|
KMID : 0545119970070050323
|
|
Journal of Microbiology and Biotechnology
1997 Volume.7 No. 5 p.323 ~ p.328
|
|
|
Fed-batch Fermentations of Recombinant Escherichia coli to Produce Bacillus macerans CGTase
|
|
Park, Yong Cheol
Kim, Chang Sup/Kim, Chung Im/Choi, Kyu Hwan/Seo, Jin Ho
|
|
|
Abstract
|
|
|
|
The recombinant Escherichia coli BL21(DE3)pLysE : pTCGT1 was grown to overproduce Bacillus macerans cyclodextrin glucanotransferase (CGTase) able to synthesize α-cyclodextrin (CD) with a selectivity of 67%. A number of batch fermentations were performed to test the possibility of using lactose as an inducer of the E. coli T7 promoter system. A mixture of isopropyl β-D-thiogalactoside (IPTG) and lactose (1 : 1) gave a maximum CGTase activity of 2.4 U/㎖, which was higher than the value obtained with induction by IPTG alone. Fed-batch fermentations involving a glucose-controlled growth period followed by a gene-expression phase with mixtures of IPTG and lactose were employed to achieve high cell density and thereby increase total CGTase activity. Optimized fed-hatch fermentation using the modified inducer (IPTG : lactose=1 : 3) and 100 g/ℓ yeast extract solution in the gene-expression phase resulted in a maximum CGTase activity of 62.9 U/㎖ and a final cell mass of 53.5 g/ℓ, corresponding to a 31-fold increase in CGTase activity and a 29-fold increase in cell mass compared with the control hatch fermentation.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|