枯草芽孢杆菌中的麦芽糖操纵子作为糖转运代谢系统中重要的组成部分，与木糖等糖代谢操纵子相比，其调控模型目前仍然存在许多未明确之处。其中转录因子glvR对操纵子及内部各个基因的转录调控机制是核心问题。本项目通过启动子截短突变体分析、EMSA、定点突变等手段，对转录调控因子glvR的调控位点（operator）、序列保守性、操纵子基因调控机制等方面进行研究，完善枯草芽孢杆菌中麦芽糖操纵子的转录调控模型。同时利用glvR的转录激活机制建立新型诱导表达系统，结合新型高通量突变筛选手段，挖掘限制表达效率的瓶颈因素，从而达到解除限制、完善表达系统的目的，也为解析枯草芽孢杆菌中异源蛋白表达问题提供技术手段和理论基础。

Maltose operon is an important component of the sugar transfer-metabolic system in Bacillus subtilis. In contrast to the well-known xylose operon and others, the precise regulatory mechanism of maltose operon is still unclear, especially for the transcription factor glvR and its regulation function on different genes in maltose operon. To improve the maltose operon regulatory model, this project focus on the analysis of glvR binding site (operator), sequence conservation and the transcriptional activation mechanism by generating different promoter truncated mutants, EMSA assay and site-directed mutagenesis technique. Meanwhile, a novel maltose-induced expression system that based on the transcriptional activator glvR is constructed in Bacillus subtilis. To optimize this expression system further, we intend to excavate the potential bottleneck factors between high expression mutant strains and wild type ones by a new high-throughput screening method. These results can be well utilized in heterologous protein expression optimization in Bacillus subtilis.