B. Yongsmith et al., Color mutants of Monascus sp KB9 and their comparative glucoamylases on rice solid culture, J MOL CAT B, 10(1-3), 2000, pp. 263-272
Monascus sp. KB9 strain was used to convert carbohydrate base agricultural
commodities to value added pigments. Mutagenesis of this strain using UV li
ght and successive isolation was found to improve the yield of pigment prod
uct. As a result, two hyper pigment productive strains, red and yellow muta
nts were obtained. In addition, one white mutant was also obtained. These c
olor mutants together with their parental strain were used to compare gluco
amylase production in rice solid culture. Initial moisture content of rice
at 35-43% is found to affect glucoamylase of these four strains. It is note
worthy that the white mutant which lost its ability to produce pigment and
revealed morphology indifference to its parental strain could produce the h
ighest glucoamylase enzyme at 4.07 x 10(5) U/gdw (units per gram-dry weight
). This is about 3, 7, and 16 times higher than the wild type strain, red,
and yellow mutants, respectively. The crude enzyme showed its thermophilic
property at optimal temperature, 65 degrees C, and its optimal pH, 4.7. (C)
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