title: High-level expression and biochemical characterization of a novel cold-active lipase from Rhizomucor endophyticus.
abstract: OBJECTIVE
  To identify novel cold-active lipases from fungal sources and improve their production by heterologous expression in Pichia pastoris.
  
  
  RESULTS
  A novel cold-active lipase gene (ReLipB) from Rhizomucor endophyticus was cloned. ReLipB was expressed at a high level in Pichia pastoris using high cell-density fermentation in a 5-l fermentor with the highest lipase activity of 1395 U/ml. The recombinant lipase (RelipB) was purified and biochemically characterized. ReLipB was most active at pH 7.5 and 25 °C. It was stable from pH 4.5-9.0. It exhibited broad substrate specificity towards p-nitrophenyl (pNP) esters (C2-C16) and triacylglycerols (C2-C12), showing the highest specific activities towards pNP laurate (231 U/mg) and tricaprylin (1840 U/mg), respectively. In addition, the enzyme displayed excellent stability with high concentrations of organic solvents including cyclohexane, n-hexane, n-heptane, isooctane and petroleum ester and surfactants.
  
  
  CONCLUSIONS
  A novel cold-active lipase from Rhizomucor endophyticus was identified, expressed at a high level and biochemically characterized. The high yield and unique enzymatic properties make this lipase of some potential for industrial applications.
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Duan
authors.affiliation: Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, 430062, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors.forename: Zhengqiang
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083, China. ysq@cau.edu.cn.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Yang
mesh_terms: D004789:Enzyme Activation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000235:genetics / Q000378:metabolism*; D010843:Pichia / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D020103:Rhizomucor / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D012997:Solvents / Q000494:pharmacology; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature
chemical_list: D012997:Solvents; D008049:Lipase
keywords: Cold active lipase; Gene cloning; Lipase; Organic solvent tolerance; Pichia pastoris; Rhizomucor endophyticus