文献类型：期刊文献

英文题名：In vivo functional expression of an extracellular Ca2+-independent Bacillus pumilus lipase in Bacillus subtilis WB800N

作者：Ma, Jing[1];Ma, Yushu[1];Wei, Wei[1];Wei, Dong-zhi[1]

机构：[1]E China Univ Sci & Technol, Newworld Inst Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2015

卷号：65

期号：4

起止页码：1973

外文期刊名：ANNALS OF MICROBIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000364945100017)】；

基金：This research was financially supported by the Fundamental Research Funds for the Central Universities of China, the Open Funding Project of the State Key Laboratory of Bioreactor Engineering, the National Natural Science Foundation of China (No. C050203-31200596), the National High Technology Research and Development Program of China (No. 2013AA102109) and the National major science and technology projects of China (No. 2012ZX09304009).

语种：英文

外文关键词：Strain screening; Lipase; Gene cloning; Enzymatic properties; Bacillus subtilis expression

摘要：A strain showing distinct lipase activity was isolated from food factory sewage and identified as Bacillus pumilus (named Bacillus pumilus Nws-bp1) by 16S rRNA sequence analysis. The wild-strain Nws-bp1 showed maximum lipase activity of 2.91 U/ml. Meanwhile, the lipase gene (named lip(BP)) was obtained from strain Nws-bp1 with the assistance of homology analysis. The gene has an open reading frame of 648 bp encoding 215-amino-acid lipase (Lip(BP)) with 34-amino-acid putative signal peptide, and shows highest identity with the lipase from Bacillus pumilus MTCC B6033 (CP007436.1). Also, the lip(BP) gene without signal peptide sequence was expressed in Bacillus subtilis WB800N using amyQ (encoding an amylase) signal peptide. The lipase total enzyme activity was 44.15 U/ml which was about 15 times higher than that of the parent strain, and in supernatant was 32.29 U/ml (about 73 % of the total activity). The pH and temperature optima were pH 10.0 and 40 degrees C, respectively. Moreover, the recombinant Lip(BP) showed apparent stability under alkaline conditions especially at pH 9.0-11.0. Also, Lip(BP) showed stability under normal temperature and retained 85 % of the residual activity after incubation at 40 degrees C for 8 h without substrate. The specific activity of purified Lip(BP) was 2650+/-117 U/mg (pNPP substrate). The K-m and V-max values of purified Lip(BP) were 1.36 mM and 208.25 mu mol/(ml.min), respectively. This is the first report of Bacillus pumilus lipase expressed in Bacillus subtilis using amyQ signal peptide, and the pH stability and organic solvent tolerance recombinant lipase provide its potential value in industrial applications.