一种新型青霉红色素的二元发酵机制

In this project, the reason of an interesting phenomenon,a potential red pigment which is overproduced when Penicillium novae-zeelandiae HS07B is co-cultured with Candida tropicalis, does not appear during the monoculture of P. novae-zeelandiae HS07B,will be studied. After the optimization of fermentation parameters, the red pigment is prepared and purified,and the chemical structures of the main components will be analyzed by the infrared spectroscopy, mass spectrometry,and nuclear magnetic resonance spectroscopy techniques. Based on their chemical structures, the biochemical synthetical pathways will be deduced and validated. Then, the fermentation mechanisms of the red pigment will be investigated from the aspects of the morpological and physiological changes of the penicillium hyphae, biochemical synthetical pathways of the red pigment, and the difference at molecular biology level analyzed by RNA sequencing, gene over-express and RNA interference. The relationship between interaction of the penicillium and yeast and the production of red pigment will be clarfied.This project has both theoretic and applicable importance.On one hand,the results of the study will be helpful for the yield optimization, metabolism regulation of the red pigment, and the application of the red pigment in the food or other industries; on the other hand, the explaination of the interesting interaction between microorganisms, especially the clarification of inducement mechanism of the novel compound of the red pigment, will be beneficial to the production of the pigment and other novel substances using the microbial co-culture.

本项目针对新西兰青霉（Penicillium novae-zeeland）和假丝酵母（Candida sp.HSDO7A）单独培养均不产生色素、但在混合培养时产生大量新颖红色素这一有趣的生物学现象展开研究。通过优化发酵工艺，提高色素产量，制备红色素样品，并对红色素组分进行分离纯化，利用红外光谱、质谱、核磁共振等技术，解析红色素中主要组分的化学结构。根据其化学结构分析各组分的生化合成途径。在此基础上，从青霉菌形态学、生理学变化、生化合成及分子生物学层面（转录组分析、基因功能研究）解析红色素主要组分的生物合成及二元发酵机制，系统剖析新西兰青霉和假丝酵母是如何相互作用并导致红色素产生。从应用角度来讲，本课题将为这一新型红色素的代谢调控、生产优化及在食品等领域的开发应用提供技术支撑。从理论价值上来说，本项目将解释微生物间的奇妙的相互作用，为未来利用二元发酵技术生产其它新颖化合物提供重要的理论依据。

天然红色素是食品、轻工等工业应用最广泛的色素之一，本项目针对一种青霉酵母混合培养产生红色素的现象，进行了Penicillium novae-zeelandiae红色素二元发酵的条件优化，色素制备，主要成分的分离与纯化等，而后利用代谢组及高分辨率质谱等技术对红色素中的甜菜苷衍生物进行了结构鉴定，此外，利用转录组分析了甜菜苷产生过程中产色素青霉菌丝与不产色素青霉菌丝中差异基因的表达，并根据代谢组及转录组信息构建了甜菜苷在该真菌中的合成代谢通路，揭示青霉红色素的二元发酵机理。在此基础上，利用基因敲除技术敲除E9: [EC:4.1.1.28]基因，抑制青霉黄色素的产生，提高红色素的发酵产量，得到的突变株与对照相比，红色素产量均有一定幅度的提高（6-10%），杂质的去除与产量的提升有利于以后的产业化推广。项目组圆满的完成了项目设计的内容，在该基金的支持下，项目组共发表SCI论文3篇，核心期刊2篇，申请国家发明专利2项，投稿SCI论文1篇，达到了预期设定的任务目标。