小分子信号调控的种群间相互作用的传统发酵食品群落构建机理的研究

The microbial communities of traditional soysauce fermentation process were formed by long-term acclimating under extreme environments condition. And then, the niches changed regularly resulted in the periodic succession of the community composition during the process. The communities perturbed via a variety of patterns such as cross-feeding, co-culture in isolated set et al are characterized based on polyphase analyzing technology. It will be investigated according to the feature of their physiological and ecological characteristics that the interspecies interactions among communities drive the change of the key components, pathways, nodes as well as key enzymes and metabolic regulation by the aspects of community physiology and system biology. It is explored that the mechanism of the community constituted, ecological function formed and co-evolution driven by regulating of interspecies interaction via the signal molecular in the metabolic constituents. Correlation between metabolic regulation and volatile components synthesized by the community is understood. The results obtained will lay a theoretical foundation for the engineering of the distinctive community in Chinese traditional fermentation food process. At the same time, the research methods also help the development of microbial ecology theory.

我国传统发酵酱油生产涉及的微生物群落是在极端环境下长期驯化形成的，而且在其生产过程中，其微环境条件又是有规律地变化，致使其群落周期性交替。本项目基于多相分析检测技术，采用各种扰动策略（隔离共培、营养互养）研究群落变化规律。从群落生理学、系统生物学方面了解菌群相互作用的生理生态性质、认识其关键代谢组分、途径、节点及关键酶及代谢调节特征。探讨代谢物组中具有信号功能组分参与的种群相互作用调控的群落构成、生态功能化形成及共进化的机理。揭示群落代谢调控与挥发性组分的相关性。研究结果为我国传统发酵食品微生物生态学的工程化奠定理论基础。同时，其研究方法也有助微生物生态学理论的发展。

以酱油发酵过程为对象，以不同种属的菌株的纯培养物组成的菌群，对其过程扰动，比较了其群落及代谢组分的异同。研究了过程参数、原料等对群落及代谢组分的影响规律。同时研究了C.versatilis CGMCC 3790和T. halophilus CGMCC3792降解AFB1的机理。主要结果如下：.1)菌群扰动对其代谢组分的影响与所用菌株的代谢特性及相互作用有关。脱脂大豆的酱醪中醇和酚类组分含量较高，长链脂肪酸酯(LFAE)和不饱和短脂肪酸(USFAE)是优势脂肪酸。扰动的结果使乙醇和游离氨基酸含量增高，异黄酮的显著高于黄豆酱醪的，其 Leuconostoc为优势细菌，使 Ralstonia, Corynebaterium1 和 Aspergillus 的丰度增加， Staphylococcus 减少，培养基的扰动作用则是使Weissella 和 Leuconostoc 减少, 但Staphylococcus增加。扰动的黄豆酱醪中长链脂肪酸酯(LFAE)和不饱和短脂肪酸为优势挥发组分，使 Ochrobacterum, Ralstonia 和Staphylococcus 的丰度增高，使Bacillus, Enterococcus, Lactobacillus, Escherichia-Shigella和Paracoccus 减少。.2）静压和发酵温度，也重要的小分子信号分子。高静压致使酱醪中Zygosaccharomyce 和隶属于Saccharomycetales的未确定属的丰度增高，但减少了Aspergillus的丰度。同时使得酵母和乳酸共混扰动的挥发组分减少了47.53%，主要是作为重要信号分子的苯乙醇及葵醛和4-乙基愈创木酚分别减少了17.67%及29.11%he 14.97%所致。 而使酵母菌群扰动酱醪的挥发组分增加了12.10%。控温发酵对挥发性组分的影响与参与扰动的菌群构成有关，酵母菌群扰动则分别使醇、酚和其它组分的含量提高了23.25% 、80.62%和25.83%。 同样是因作为重要信号分子的苯乙醇、4-乙基愈创木酚和4-乙基酚含量提高所致。作为重要的信号小分子苯乙醇与Weissella 和 Leuconostoc正相关。. 3）C.versatilis CGMCC 3790降解AFB1产物的结构涉及直接转化为V(C11H10O4)组分和将其转化为II(C