title: Improved production of an enzyme that hydrolyses raw yam starch by Penicillium sp. S-22 using fed-batch fermentation.
abstract: 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.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, Southern Yangtze University, Wuxi 214036, JiangSu Province, P.R. China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Sun
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Ge
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Zhang
mesh_terms: D019149:Bioreactors; D027742:Dioscorea / Q000378:metabolism*; D005285:Fermentation; D007218:Industrial Microbiology / Q000379:methods*; D007700:Kinetics; D010407:Penicillium / Q000201:enzymology*; D013213:Starch / Q000378:metabolism*
chemical_list: D013213:Starch