title: Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.
abstract: A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry.
authors.affiliation: State Key Laboratory of Food Science & Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.|College of Food Science and Engineering, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Dong
authors.affiliation: School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Mohammed A A
authors.initials: MAA
authors.lastname: Gasmalla
authors.affiliation: State Key Laboratory of Food Science & Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.|School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: College of Food Science and Engineering, Shihezi University, Shihezi, Xinjiang, People's Republic of China.
authors.forename: Jingtao
authors.initials: J
authors.lastname: Sun
authors.affiliation: Xinjiang Shihezi Vocational Technical College, Shihezi, Xinjiang, People's Republic of China.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Liu
authors.affiliation: School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Wang
authors.affiliation: School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Han
authors.affiliation: State Key Laboratory of Food Science & Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.|School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Ruijin
authors.initials: R
authors.lastname: Yang
mesh_terms: D000220:Adaptation, Biological; D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D004795:Enzyme Stability; D004950:Esterases / Q000032:analysis / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D046448:Ice Cover / Q000382:microbiology; D008049:Lipase; D009154:Mutation / Q000235:genetics; D011549:Pseudomonas / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D004950:Esterases; D008049:Lipase
keywords: ARTP; Pseudomonas sp; characterization; cold-adapted esterase/lipase; single cream