• Journal of Microbiology and Biotechnology
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• 제3권2호
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• pp.78-85
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• 1993

In order to elucidate the mechanism which regulates the production of cyclodextrin glucanotransferase (CGTase) and to achieve overproduction of CGTase by releasing catabolite (glucose) repression, several catabolite repression resistant mutants were selected from newly screened Bacillus firmus var. alkalophilus H609, after NTG (N-methyl-N -nitro-N-nitrosoguanidine) treatment, using 2-deoxyglucose as a nonmetabolizable analog of catabolite glucose and as a selection marker. Five catabolite repression resistant mutants were selected from about 30, 000 2-deoxyglucose resistant colonies. Relative catabolite repression indices of the selected mutants were in the range of 8~80% assuming 100% for parent strain. The amount of CGTase produced by the mutant strain CR41, which was 250 units/ml, was three times larger than that produced by its parent strain. The mutation seems to have occurred in the regulatory region of CGTase gene and not in the structural region or the glucose transporting system in cell membrane. The enzymatic properties of CGTase excreted from parent and mutant strains were also compared.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.549-555
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• 1993

The production of cellulase by Pseudomonas sp. LBC505 isolated was under the strict genetic and biochemical control mechanisms such as catabolit repression and induction. These biochemical control reduced cellulase production. Thus LBC505 was mutated to increase enzyme yields. Cells growth and cellulase production were inhibited by the addition of 2-deoxy glucose (2-DG), which is presumed to function as repressor for the selection of high cellulase yielding mutant.