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https://hdl.handle.net/2440/54211
Type: | Journal article |
Title: | Purification and characterization of three alkaline endopolygalacturonases from a newly isolated Bacillus gibsonii |
Author: | Li, Z. Jin, B. Zhang, H. Bai, Z. Xue, W. Li, H. |
Citation: | Guocheng Gongcheng Xuebao, 2008; 8(4):768-773 |
Publisher: | Kexue Chubanshe |
Issue Date: | 2008 |
ISSN: | 1009-606X |
Statement of Responsibility: | LI, Zu-ming; JIN, Bo; ZHANG, Hong-xun; BAI, Zhi-hui; XUE, Wen-tong and LI, Hong-yu |
Abstract: | A newly isolated Bacillus gibsonii, designated as S-2 (CGMCC1215), was cultivated for production of alkaline pectinases utilizing sugar beet pulp as growth substrate. Purification of three alkaline endopolygalacturonases (endoPGs) from the crude pectinases extract was carried out by ultra-filtration, ammonium sulphate fractionation and ion-exchange chromatography, and their enzyme activities characterized. The three purified alkaline endoPGs, designated as S-I, S-II, and S-III, had a molecular weight about 38 kDa as determined by SDS-PAGE. The Km value and optimal temperature for optimal enzyme activities of S-I, S-II and S-III were 1.2 mg/mL and 60°C, 0.9 mg/mL and 55°C, 1.1 mg/mL and 60°C, respectively. Their best performances were given at an optimal pH 10.5, and sodium polygalacturonate was found to be the best substrate. The isoelectric points of S-I, S-II and S-III were 5.4, 7.4, and 8.2, respectively. Surfactants of Tween-80 and Tween-20 and metal ions such as Mg2+ and Ca2+ stimulated the activity of S-I, S-II and S-III, whereas S-III was inhibited by Ca2+, and Mn2+ and Zn2+ ions inhibited the activity of the three enzymes. |
Keywords: | alkaline endopolygalacturonases Bacillus gibsonii purification enzyme activity |
Appears in Collections: | Aurora harvest 5 Earth and Environmental Sciences publications Environment Institute publications |
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