Key Laboratory of Carbohydrate Chemistry & Biotechnology Ministry of Education, & School of Biotechnology, Jiangnan University, Wuxi 214122, China.
Key Laboratory of Carbohydrate Chemistry & Biotechnology Ministry of Education, & School of Biotechnology, Jiangnan University, Wuxi 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.
Carbohydr Polym. 2015 Nov 20;133:104-9. doi: 10.1016/j.carbpol.2015.07.014. Epub 2015 Jul 13.
We investigated the relationship between monosaccharide composition of Ganoderma lucidum exopolysaccharide (EPS) and activities of EPS synthesis enzymes under various culture temperatures and initial pH values. The mole percentages of three major EPS monosaccharides, glucose, galactose and mannose, varied depending on culture conditions and the resulting EPS displayed differing anti-tumor activities. In nine tested enzymes, higher enzyme activities were correlated with higher temperature and lower initial pH. Altered mole percentages of galactose and mannose under various culture conditions were associated with activities of α-phosphoglucomutase (PGM) and phosphoglucose isomerase (PGI), respectively, and that of mannose was also associated with phosphomannose isomerase (PMI) activity only under various pH. Our findings suggest that mole percentages of G. lucidum EPS monosaccharides can be manipulated by changes of culture conditions that affect enzyme activities, and that novel fermentation strategies based on this approach may enhance production and biological activity of EPS.
我们研究了在不同培养温度和初始 pH 值下，灵芝胞外多糖 (EPS) 的单糖组成与 EPS 合成酶活性之间的关系。三种主要 EPS 单糖（葡萄糖、半乳糖和甘露糖）的摩尔百分比取决于培养条件，所得 EPS 显示出不同的抗肿瘤活性。在测试的九种酶中，较高的酶活性与较高的温度和较低的初始 pH 值相关。在各种培养条件下，半乳糖和甘露糖的摩尔百分比分别与α-磷酸葡萄糖变位酶 (PGM) 和磷酸葡萄糖异构酶 (PGI) 的活性相关，而甘露糖的摩尔百分比也仅与各种 pH 值下的磷酸甘露糖异构酶 (PMI) 活性相关。我们的研究结果表明，通过改变影响酶活性的培养条件，可以操纵灵芝 EPS 单糖的摩尔百分比，并且基于这种方法的新型发酵策略可能会提高 EPS 的产量和生物活性。
