保加利亚乳杆菌蛋白酶的凝乳特性及其相关基因发掘研究

项目名称： 保加利亚乳杆菌蛋白酶的凝乳特性及其相关基因发掘研究

项目编号： No.31271906

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 张兰威

作者单位： 哈尔滨工业大学

项目金额： 86万元

中文摘要： 保加利亚乳杆菌是酸奶发酵剂的重要菌种之一，其特性及代谢产物与品质、品种多样化密切相关。前期研究表明，不同乳酸菌（或菌株）产蛋白酶的能力存在很大差异，对牛乳凝乳、发酵乳流变学特性、质地和感官性质有很大影响。本项目拟以前期筛选得到的生产性能优良、具有明显产蛋白酶能力的保加利亚乳杆菌为研究对象，从基因组学和酶学角度揭示保加利亚乳杆菌蛋白酶的多样性及对发酵乳品质的影响。通过现代色/光谱技术与和质谱技术及生物信息学手段深入研究保加利亚乳杆菌蛋白酶酶系构成的多态性；利用激光共聚焦技术、荧光染色技术、纳米激光粒度分析技术、凝胶渗透色谱技术、RP-HPLC和LC/ESI/MS技术，从多尺度、多层面探讨蛋白酶促进牛乳凝乳的作用机理；利用微阵列-比较基因组杂交技术发掘促凝乳蛋白酶组分关键基因，研究酸胁迫下该蛋白酶的分泌表达。本项目旨在为高品质、差异化发酵乳的社会需求提供理论依据和基础。

中文关键词： 保加利亚乳杆菌；蛋白酶；凝乳特性；凝乳酶基因；

英文摘要： Lactobacillus bulgaricus is one of the dominate bacteria for yoghurt starter cultures. Its fermentation characteristics and metabolic mechanism have the close relationships with the quality and diversity of yoghurt products. In our previous study we found there are great different for L. bulgaricus to synthesis of proteinases and significantly effect on the coagulation of milk, rheological characteristics of fermented milk and texture and sensory characteristics. The protease produced L. bulgaricus with the excellent production performance were screened in our previous study and used as the objective strains. Genomics and enzymology were utilized to reveal diversity of the protease produced by L. bulgaricus affect on quality of fermented milk. Modern chromatography/spectroscopy, mass spectrometry and bioinformatics were also used to deeply study the diversity components of the protease. In addition, confocal microscopy, fluorescent staining technique, nanometer laser particle size analysis, gel permeation chromatography, RP-HPLC and LC/ESI/MS technique were implied to investigate the mechanism of the protease promote milk coagulation. Array-based comparative genomic hybridization techniques were also utilized to identify the key genes of promote milk coagulation protease component and the secretion and expressio

英文关键词： Lactobacillus bulgaricus；protease；coagulation；rennin gene；