短小芽孢杆菌β-1，4-甘露聚糖酶的酶学性质及其在干酪乳杆菌中的表达

Characterization of β-1，4-mannanase from Bacillus pumilus and heterologous expression in Lactobacillus casei

摘要:

摘要:【目的】干酪乳杆菌广泛的应用于食品加工和饲料行业，本研究拟构建表达甘露聚糖酶的重组干酪乳杆菌并进行相关评价。【方法】利用干酪乳杆菌表达载体pELX1和pELSH，将短小芽孢杆菌的β-1，4-甘露聚糖酶成熟肽的基因克隆到上述两个载体中，构建的重组质粒电转化到干酪乳杆菌宿主中，分别构建能够胞内表达和分泌表达甘露聚糖酶的重组干酪乳杆菌。【结果】重组干酪乳杆菌菌株经培养后，胞内表达的β-1，4-甘露聚糖酶在重组细胞总蛋白中最高可达23 U/mg，分泌表达培养基上清的β-1，4-甘露聚糖酶最高达到8.8 U/mL。【结论】本研究首次实现了甘露聚糖酶在干酪乳杆菌中的表达，结果表明该重组干酪乳杆菌具有较大的应用前景，值得进一步研究。

Abstract:

Abstract:［Objective］Lactobacillus casei is widely used in food production and feed industry. The aim of this study was to construct the recombinant expression mannanase Lb. casei.［Methods］The mature peptide gene of β-1，4-mannanase from Bacillus pumilus was cloned into expression vectors pELX1 and pELSH，then electroporated into Lb．casei，establishing an intracellular and a secretion expression mannanase Lb． casei respectively.［Results］After incubation，the specific activity of β-1，4-mannanase was 23 U/mg whole cell protein for intracellular expression and 8.8 U/mL forsecretion expression in supernatant.［Conclusion］Mannanase gene expression in Lb．casei provides application prospect and deserves further study．