title: Production optimization of a heat-tolerant alkaline pectinase from Bacillus subtilis ZGL14 and its purification and characterization.
abstract: Alkaline pectinase has important applications in the pretreatment of waste water from food processing and in both the fabric and paper industries. In this study, a 2-level factorial design was used to screen significant factors that affect the activity of alkaline pectinase, and the response surface methodology (RSM) with a Box-Behnken design (BBD) was used to optimize their concentrations. Starch, peptone, KH2PO4and K2HPO4·3H2O were found to significantly affect the activity of alkaline pectinase. Their optimal concentrations were as follows: 4.68% starch, 1.6% peptone, 0.26% KH2PO4and 0.68% K2HPO4·3H2O. Under the above conditions, the activity of alkaline pectinase was significantly improved to 734.11 U/mL. Alkaline pectinase was purified to homogeneity with a recovery rate of 9.6% and a specific activity of 52372.52 U/mg. Its optimal temperature and pH were 50°C and 8.6, respectively. The purified enzyme showed strong thermo-stability and good alkali resistance. In addition, the activity of alkaline pectinase was improved in the presence of Mg2+. Cu2+, Mn2+, and Co2+significantly inhibited its activity. This study provides an important basis for the future development and use of a heat-tolerant alkaline pectinase from B. subtilis ZGL14.
authors.affiliation: a College of Food Science and Biotechnology, Zhejiang Gongshang University , Hangzhou , Zhejiang Province , People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yu
authors.affiliation: a College of Food Science and Biotechnology, Zhejiang Gongshang University , Hangzhou , Zhejiang Province , People's Republic of China.
authors.forename: Yishu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: a College of Food Science and Biotechnology, Zhejiang Gongshang University , Hangzhou , Zhejiang Province , People's Republic of China.
authors.forename: Donglu
authors.initials: D
authors.lastname: Gu
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D001412:Bacillus subtilis / Q000145:classification* / Q000201:enzymology*; D019149:Bioreactors / Q000382:microbiology*; D003198:Computer Simulation; D003470:Culture Media / Q000378:metabolism; D004789:Enzyme Activation; D004795:Enzyme Stability; D008670:Metals / Q000737:chemistry; D008954:Models, Biological; D011096:Polygalacturonase / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification; D013045:Species Specificity; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000468:Alkalies; D003470:Culture Media; D008670:Metals; D011096:Polygalacturonase
keywords: Bacillus subtilis ZGL14; alkaline pectinase; characterization; enzymatic properties; optimization; response surface methodology