碳源对里氏木霉QM9414胞外酶基因表达的影响

Affect of carbon source on extracellular enzyme gene expression in Trichoderma reesei QM9414

对里氏木霉QM9414在纤维素、木聚糖、乳糖、甘油、葡萄糖等不同碳源培养条件下,纤维素酶、木聚糖酶的活性差异以及其培养液中总分泌蛋白的表达差异进行了分析.发现纤维素、乳糖和木聚糖均可诱导纤维素酶和木聚糖酶的合成;而葡萄糖是两种酶合成的抑制性碳源.通过对不同碳源培养条件下,里氏木霉QM9414培养液中总分泌蛋白的SDS-PAGE分析,获得其分泌蛋白表达谱.选取差异表达的蛋白,进行质谱分析,获得4个蛋白序列.根据里氏木霉基因组数据库序列的同源性分析发现:乳糖诱导了一个与海藻糖酶同源的蛋白;而木聚糖诱导产生了一个未知的蛋白质高表达;纤维素为碳源诱导产生了与阿拉伯糖酶同源的蛋白质;葡萄糖为碳源诱导产生与水解α-1,4-糖苷键的淀粉酶同源的蛋白质;根据同源性分析,不同碳源诱导产生的蛋白都是与碳源利用有关的糖苷键水解酶.

This study analyzes the Trichoderma reesei cellulase and xylanase activity and its total secreted protein expression differences that in the culture medium contains cellulase,xylan,lactose,glycerol and glucose.It indicates that cellulose,lactose and xylan can all induce cellulase and xylanase synthesis.At the same time,glucose as carbon nutrition makes activity of these two enzymes are very low,so it shows that glucose is the inhibitory carbon nutrition of the two enzymes.It analyzes the total secreted proteins of Trichoderma reesei that in the culture solution contains different carbon nutrition used SDS-PAGE,access to the secreted protein expression profiling,and the difference is v ery significantly.Differential expression of proteins in the different carbon nutrition conditions is selected,and analyzed by mass spectrometry to obtain four protein sequences,according to Trichoderma reesei genome database sequence homology analysis： Lactose induces a trehalase homologous protein,xylan induces an unknown protein high expression,cellulose induces an arabinase homologous protein,glucose induces a hydrolyzed α-1,4-glycosidic bonds amylase homologous protein,and glycerol induces an unknown protein.Homology analysis demonstrates that the proteins induced by different carbon nutritions are all related to the glycosidic bond hydrolase.