Publication Date:
2012-05-01
Description:
In this study, the mph gene encoding methyl parathion hydrolase from Pseudomonas sp. WBC-3 was expressed in Yarrowia lipolytica and the expressed methyl parathion hydrolase was displayed on cell surface of Y. lipolytica. The activity of methyl parathion hydrolase displayed on the yeast cells of the transformant Z51 was 59.5 U mg −1 of cell dry cells (450.6 U per mL of the culture) in the presence of 5.0 mM of Co 2+ . The displayed methyl parathion hydrolase had the optimal pH of 9.5 and the optimal temperature of 40 °C, respectively and was stable in the pH range of 4.5–11 and up to 40 °C. The displayed methyl parathion hydrolase was also stimulated by Co 2+ , Cu 2+ , Ni 2+ and Mn 2+ , and was not affected by Fe 2+ , Fe 3+ , Na + , K + , Ca 2+ and Zn 2+ , but was inhibited by other cations tested. Under the optimal conditions (OD 600nm = 2.6, the substrate concentration = 100 mg L −1 and 40 °C), 90.8 % of methyl parathion was hydrolyzed within 30 min. Under the similar conditions, 98.7, 97.0, 96.5 and 94.4 % of methyl parathion in tap water (pH 9.5), tap water (pH 6.8), seawater (pH 9.5) and natural seawater (pH 8.2) were hydrolyzed, respectively, suggesting that the methyl parathion hydrolase displayed on the yeast cells can effectively remove methyl parathion in water. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10532-012-9551-z Authors Xing-Xing Wang, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Zhe Chi, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Shao-Guo Ru, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Zhen-Ming Chi, School of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, China Journal Biodegradation Online ISSN 1572-9729 Print ISSN 0923-9820
Print ISSN:
0923-9820
Electronic ISSN:
1572-9729
Topics:
Biology
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Energy, Environment Protection, Nuclear Power Engineering
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Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
