基于纯种接种的预发酵椰子水促进细菌纤维素合成的代谢组学研究

BC因优良独特性能而持续受到越来越广泛关注。本项目基于商业生产使用自然预发酵椰子水FCW比新鲜水NCW能成几十倍促进BC合成的事实，首次提出以广泛靶向代谢组学研究K. nataicola BC合成代谢调控机制。首先对已筛获具有促进作用单菌株进行多维复合组合筛选，并进行组合接种预发酵条件优化，以获取产量高于FCW的组合菌株纯种预发酵高促进椰子水。然后选取其代表性时点预发酵椰子水跟NCW一起进行常规成分测定。接着基于UPLC-MS/MS和GC-MS进行广靶研究、多元统计分析寻找各预发酵椰子水组内、与NCW组间的差异代谢物及其关系、基于KEGG进行功能注释并进行代谢通路富集分析，解析可能在BC合成中发挥调控作用的关键促进和/或抑制因子。最后基于HS培养基进行加标验证，测定K.nataicola发酵BC性能、细胞内UDPG焦磷酸化酶等关键酶活力，最终通过综合分析阐释该菌种BC生物合成代谢调控规律。

BC has received more and more attention because of its excellent unique properties. This project is based on the fact that commercial production using natural pre-fermented coconut water (FCW) can promote BC synthesis by dozens of times than fresh natural coconut water(NCW). It is the first time that a widely-targeted metabolomics is used to study the mechanism of BC synthesis by K. nataicola. Firstly, the single strains with promoting effect were combined and screened, and the pre-fermentation conditions with combined inoculation will be optimized to obtain pre-fermented water with higher yield than FCW. Then we select the representative time point of pre-fermented coconut water and NCW for routine composition analysis. Then, based on UPLC-MS/MS and GC-MS, a widely-targeted study and multivariate statistical analysis will be performed to find the differential metabolites and their relationships between each pre-fermented coconut water group and also the NCW group, and based on KEGG database for functional annotation and metabolic pathway enrichment analysis, we will demonstrate the key promotion and/or inhibitory factors that may play a regulatory role in BC synthesis. Finally, based on the HS medium, the standard verification will be carried out, and by determining the BC fermentation performance of K. nataicola, and the activities of the key enzymes such as UDPG pyrophosphorylase, we will demonstrate the mechanism of BC biosynthesis metabolic regulation through comprehensive analysis.