哈氏噬纤维菌（Cytophaga hutchinsonii）具有极强的结晶纤维素降解能力，但其纤维素降解过程及过程其调控机理尚未得到阐明。胞质外功能（ECF）σ因子所介导的基因表达模式改变是原核生物细胞响应环境信号变化的重要途径之一。我们在前期研究中发现了一个影响哈氏噬纤维菌降解利用纤维素的ECF σ 因子基因簇。本项研究拟对该因子在纤维素利用过程中的作用机制进行系统研究，主要包括对基因簇中ECF σ 因子(SigC)和anti-σ因子(SigAC)的结构功能、两者间相互作用模式及其动态变化、SigC所控制的碳源响应基因网络进行研究，深入阐述SigC的活性控制机制及其在哈氏噬纤维菌纤维素利用过程中的调控机制, 从而丰富和发展纤维素降解的理论体系, 为建立和发展纤维素转化利用的新策略提供理论基础。

•.Cytophaga hutchinsonii is a common cellulolytic soil bacterium belonging to the phylum Bacteroidetes. Cells of C. hutchinsonii are capable of actively digesting crystalline cellulose using a third but poorly understood strategy to digest cellulose. The precise aspects of the digesting process as well as how the process is controlled is largely unknown. The pattern of gene expression dedicated by the extracytoplasmic function (ECF) σ factor has been thought to constitute the thrid pillar of bacteria signal transduction in response to changes in environmental cues. Our previous study identified an ECF σ encoding gene whose insterted mutation resulted in the inability of C. hutchinsonii to digest filter paper. Immediately adjacent to this gene locus is a gene coding for a protein predicted to be a cognate anti-σ factor. The present project thus intends to fully characterize the ECF σ/anti-σ pair, trying to elucidate the mechanism by which this ECF σ system participates in controlling the cellulose degradation in Cytophaga hutchinsonii. The project will focus on the structure and function of the ECF σ and anti-σ, the pattern of their interactions and how this interaction pattern changes under different conditions, the relationship between this ECF σ/anti-σ pair and a PDZ protease whose mutation also leads to cellulolytic defect but can be complemented by ECF σ, and the effect of the ECF σ may inflict on the responsive netwrok of C. hutchinsonii to carbon sources. The above results are anticipated to help elucidating the precise mechanism by which the cellulose responsive ECF σ factor is activated, and thus how the process of cellulose assimilation by C. hutchinsonii is regulated. The results will also provide the theoretical basis for the establishment and development of new strategies for the efficient conversion of cellulose by the cell-bound noncomplexed enzymatic hydrolytic system, which will enrich and develop the theoretical system of microbial degradation of cellulose.