香菇多糖生物合成代谢相关酶的研究

Study on Enzymes Related to Lentinan Biosynthesis Metabolism

以香菇菌丝体多糖含量及其生物合成相关酶的活性为研究指标,采用单因素实验和正交实验确定液体发酵的最佳条件,优化香菇菌丝体的培养工艺,找到控制菌丝体多糖生物合成代谢的关键酶。结果表明:香菇菌丝体最适碳源为40 g/L葡萄糖,最适氮源为10 g/L牛肉膏,最适发酵时间为5 d,最适pH值和培养温度为7和25℃。同时在不同发酵条件下培养香菇菌丝体,胞内葡萄糖激酶(GK)、磷酸葡萄糖变位酶(PGM)、UDP-葡萄糖焦磷酸化酶(UGP)、磷酸葡萄糖异构酶(PGI)和UDP-葡萄糖脱氢酶(UGD)活性随着多糖含量的增加而升高,表明这5种酶与香菇菌丝体多糖的生物合成有关。

In this design,the yield of mycelium polysaccharides and the activity of lentinan-synthesizing enzymes were used as the research indicators.The single factor test was used to obtain the best conditions for liquid fermentation.Then,the best culture process of Letinous edodes mycelia was optimized by orthogonal design and the key enzymes controlling polysaccharide biosynthesis of mycelia were found.The results show that the optimal fermentation time for Lentinus edodes mycelium is 5 days,and the optimal carbon source and nitrogen source are 40 g/L glucose,10 g/L beef extract,and the optimal culture pH and temperature are 7 and 25℃.At the same time,Lentinus edodes mycelium was cultured under different fermentation conditions.Intracellular glucokinase(GK),phosphoglucose mutase(PGM),UDP-glucose pyrophosphorylase(UGP),and phosphoglucose isomerase(PGI)whose activity increased with the increase of polysaccharide production indicating that these five enzymes are related to the biosynthesis of polysaccharides in Lentinus edodes mycelium.