Improved production of an enzyme that hydrolyses raw yam starch by Penicillium sp. S-22 using fed-batch fermentation.
A newly isolated strain, Penicillium sp. S-22, was used to produce an enzyme that hydrolyses raw yam starch [raw yam starch digesting enzyme (RYSDE)]. The enzyme activity and overall enzyme productivity were respectively 16 U/ml and 0.19 U/ml h in the batch culture. The enzyme activity increased to 85 U/ml by feeding of partially hydrolyzed raw yam starch. When a mixture containing partially hydrolyzed raw yam starch and peptone was fed by a pH-stat strategy, the enzyme activity reached 366 U/ml, 23-fold of that obtained in the batch culture, and the overall productivity reached 3.4 U/ml h, which was 18-fold of that in the batch culture.
Sun
Hai-Yan
HY
The Key Laboratory of Industrial Biotechnology, Ministry of Education, Southern Yangtze University, Wuxi 214036, JiangSu Province, P.R. China.
Ge
Xiang-Yang
XY
Zhang
Wei-Guo
WG
D019149:Bioreactors; D027742:Dioscorea / Q000378:metabolism*; D005285:Fermentation; D007218:Industrial Microbiology / Q000379:methods*; D007700:Kinetics; D010407:Penicillium / Q000201:enzymology*; D013213:Starch / Q000378:metabolism*
D013213:Starch