溶氧是链霉菌抗生素发酵过程中的重要参数，关系到抗生素发酵的成败，因而阐明链霉菌响应氧化还原信号的机制具有重要的理论和现实意义。氧化还原调控因子Rex是目前链霉菌中唯一被鉴定参与氧还信号响应的调控因子，但对其研究尚不深入，生物学意义尚未得以充分阐明。申请人小组前期工作表明阿维链霉菌中阿维菌素生物合成和形态分化受到rex基因的调控,本研究在现有工作基础上，以重要工业微生物阿维链霉菌中Rex调控因子为主要研究内容，对其调控功能和调控方式做深入研究，将有助于揭示Rex调控因子在链霉菌低氧胁迫响应、次级代谢、形态分化和其它重要生理过程中的调控功能，为链霉菌抗生素发酵生产中溶氧控制提供指导；同时为揭示阿维菌素生物合成的复杂调控网络积累更多的实验数据，并为利用基因工程手段构建抗生素高产菌株和低氧耐受菌株提供理论依据。

Oxygen supply is a vital parameter in the process of antibiotics fermentation in Streptomyces,therefore understanding how Streptomyces senses and responds to redox signal is very important. Though Rex was firstly identified in Streptomyces as a redox-sensing regulator, so far the overall knowledge of Rex is still sparse,and the regulatory roles of Rex are not well understood. Our previous studies showed that rex had regulatory roles in avermectin production and morphology in Streptomyces avermitilis. So based on the former work, this project focuses on the regulatory function and regulatory mechanism of Rex in importantly industrial strain Streptomyces avermitilis. The investigation will help to understand the regulatory roles of Rex in hypoxia stress response,secondary metabolism, morphology and other physiological process in Streptomyces, and provide insights into the strategy for supply control of oxygen in fermentation process. The elucidation of the mechanism will also help to understand complex regulatory network of avermectin production and suggest the strategies for genetic engineering of antibiotic high-producing strains and oxygen-tolerating strains in Streptomyces.