Isolation of a novel alkaline-stable lipase from a metagenomic library and its specific application for milkfat flavor production

Microbial Cell Factories

Research

Bo Shi¹  Xu Wang²  Guohua Guan²  Ying Li²  Meng Shang²  Jinjin Huang²  Qing Peng³ 

[1] Feed Research Institute, Chinese Academy of Agricultural Sciences, P. R., 100081, Beijing, China;State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, P. R., 100193, Beijing, China;State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, P. R., 100193, Beijing, China;Feed Research Institute, Chinese Academy of Agricultural Sciences, P. R., 100081, Beijing, China;

关键词: Metagenomic library;    Alkaline-stable lipase;    Myristic acid;    Palmitic acid;    Milkfat flavor;   

DOI  :  10.1186/1475-2859-13-1

 received in 2013-11-11, accepted in 2013-12-29,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundLipolytic enzymes are commonly used to produce desired flavors in lipolyzed milkfat (LMF) manufacturing processes. However, the choice of enzyme is critical because it determines the final profile of fatty acids released and the consequent flavor of the product. We previously constructed a metagenomic library from marine sediments, to explore the novel enzymes which have unique properties useful in flavor-enhancing LMF.ResultsA novel lipase Est_p6 was isolated from a metagenomic library and was expressed highly in E.coli. Bioinformatic analysis indicated that Est_p6 belongs to lipolytic enzyme family IV, the molecular weight of purified Est_p6 was estimated at 36 kDa by SDS-PAGE. The hydrolytic activity of the enzyme was stable under alkaline condition and the optimal temperature was 50°C. It had a high specific activity (2500 U/mg) toward pNP butyrate (pNP-C4), with Km and Vmax values of 1.148 mM and 3497 μmol∙min-1∙mg-1, respectively. The enzyme activity was enhanced by DTT and was not significantly inhibited by PMSF, EDTA or SDS. This enzyme also showed high hydrolysis specificity for myristate (C14) and palmitate (C16). It seems that Est_p6 has safety for commercial LMF flavor production and food manufacturing processes.ConclusionsThe ocean is a vast and largely unexplored resource for enzymes. According the outstanding alkaline-stability of Est_p6 and it produced myristic acid and palmitic acid more efficiently than other free fatty acids in lipolyzed milkfat. This novel lipase may be used to impart a distinctive and desirable flavor and odor in milkfat flavor production.

【 授权许可】

Unknown   
© Peng et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.