地衣芽孢杆菌胞外聚合物合成的调控机制研究

Two different types of extracellular polymeric substances ——polysaccharide and polyglutamic acids (γ-PGA) were produced in different ratios from Bacillus licheniformis CGMCC2876. At different cultivation conditions the proteomic analysis of B. licheniformis were done with SWATH-MS technique combined with genome sequencing. The metabolic networks of polysaccharide and γ-PGA were systematically compared at the levels of both genome and proteome. The key proteins were finally determined which took significant parts in extracellular polysaccharide and γ-PGA synthesis, thus the metabolic mechanisms and their relationships of the two extracellular macromolecules in B. licheniformis were clarified. This study will tell us how two different extracellular polymeric substances are cooperatively synthesized in B. licheniformis and their physiological functions will be further studied as well. The research will provide novelty to the genome and proteome databases of Bacillus spieces, and the identification of the genetic information will provide new tools to engineer B. licheniformis for polysaccharide and γ-PGA industrial production.

以地衣芽孢杆菌Bacillus licheniformis CGMCC 2876为出发菌株，考察其合成两种胞外聚合物——多糖和γ-聚谷氨酸（γ-PGA）的培养规律，采用全基因组测序和SWATH采集质谱技术，结合代谢工程手段，从基因组和蛋白质组的角度对多糖与γ-PGA合成代谢网络进行比对分析，定位参与多糖与γ-PGA代谢与调控的关键蛋白，阐明地衣芽孢杆菌两种胞外聚合物合成的代谢过程及相互关联的内在本质。该研究从基因水平上揭示地衣芽孢杆菌胞外聚合物的协调合成机制，探究其生理学功能；可望为地衣芽孢杆菌基因组和蛋白质组数据库补充新的数据，同时为具有工业应用潜力的多糖和γ-PGA的实际生产提供有效的发酵与分离制备策略。

通过考察地衣芽孢杆菌Bacillus licheniformis CGMCC 2876合成两种胞外聚合物——多糖和γ-聚谷氨酸（γ-PGA）的培养规律，从基因组、代谢组和蛋白质组等多个角度对涉及两种不同生物大分子合成代谢网络的多个基因进行比对分析，定位了代谢途径中的关键基因，进而通过构建关键基因的重组菌株，结合代谢组、荧光定量PCR技术等对其在胞外聚合物合成及菌株生长繁殖中的功能和代谢调控机制进行了深入解析。该项研究从基因水平上揭示了地衣芽孢杆菌胞外聚合物的合成机制，同时获取了部分基因新的生理学功能，可望为地衣芽孢杆菌基因组库补充新的数据，也为具有工业应用潜力的多糖和γ-PGA的实际生产提供有效的发酵策略。