地衣芽孢杆菌芽孢形成相关SigE调控蛋白分泌表达机制研究

地衣芽孢杆菌具有蛋白分泌性能强、安全性高等特点，是α-淀粉酶等工业酶生产的重要菌株。大量研究表明，芽孢形成会影响地衣芽孢杆菌蛋白质分泌表达，但对其调控机制研究较少。本项目拟以产淀粉酶地衣芽孢杆菌为出发菌，基于申请人前期筛选到对地衣芽孢杆菌蛋白分泌表达有显著影响的芽孢形成相关Sigma因子SigE (σE)，建立SigE转录机制工程技术调控多基因转录水平，结合高通量筛选，获得高蛋白分泌性能进化菌株与SigE突变体。通过对进化菌株的生理特征与组学解析，挖掘影响蛋白表达分泌的关键基因，研究SigE及关键基因对芽孢形成、蛋白分泌表达等过程的影响，解析其对芽孢形成与蛋白分泌表达的调控机制，并指导高效蛋白分泌表达菌株的改良。本项目的研究将有助于揭示芽孢形成与蛋白分泌表达的调控机制，建立安全、高效地衣芽孢杆菌蛋白分泌表达系统，拓展地衣芽孢杆菌在蛋白分泌基础研究与工业生物技术中的应用，具有重要的理论和应用

Bacillus licheniformis has been widely used in the industrial production of food enzymes, based on its strong protein secretion system and high food safety. Numerous studies have shown that sporulation is closely related to protein secretion, but the regulatory mechanism is still insufficient. This project is to take alpha-amylase-producing B. licheniensis as the research object. We will firstly establish transcriptional machinery engineering of sporulation related sigma factor SigE to regulate the transcriptional level of multiple genes. The evolved strains with significantly improved secretion will be collected by combining the growth-coupled evolution and high-throughput screening. Based on the transcriptome-proteome analyzation, we will further mine key genes affecting the protein expression and secretion and characterize the regulatory process on the secretion and sporulation. These results will further reveal the mechanism between protein expression secretion and sporulation, which provides theoretical and application guidance for improving the protein expression and secretion performance of Bacillus.