灵芝不同生长期子实体多糖含量及糖代谢相关酶活性研究

Polysaccharides Content and Activity of Enzymes Related to Sugar Metabolism from the Fruiting Bodies of Ganoderma lucidum at Different Growth Stages

研究灵芝(Ganoderma lucidum Karst)不同生长阶段子实体多糖含量和糖代谢相关酶活性的变化,初步探讨灵芝子实体多糖含量变化的酶学机制。以袋料栽培灵芝为试材,采用苯酚-硫酸法测定子实体多糖含量,分光光度法测定糖代谢相关酶活性。结果表明,3种糖代谢相关酶(己糖激酶、α-磷酸葡萄糖变位酶、磷酸葡萄糖异构酶)的活性变化趋势与子实体多糖含量的变化趋势基本一致。菌蕾期子实体多糖含量最低,为11.7mg/g。从菌蕾期开始,随着糖代谢相关酶活性逐渐升高,子实体多糖含量逐渐增加,在子实体成熟后孢子弹射前达到最大值,为23.3mg/g,此时,己糖激酶、α-磷酸葡萄糖变位酶、磷酸葡萄糖异构酶的活性也达到最大值,分别为23.9、25.1、18.7U/g。之后子实体多糖含量随着糖代谢相关酶活性的显著下降而降低,孢子弹射后,子实体多糖含量仅为16.3mg/g。三种糖代谢相关酶活性与灵芝子实体多糖含量呈现正相关,推测己糖激酶、α-磷酸葡萄糖变位酶、磷酸葡萄糖异构酶是灵芝多糖合成的关键酶。

In order to study the enzymatic mechanisms responsible for the change of polysaccharides content, the changes of polysaccharides contents and activities of sugar metabolism-related enzymes from the fruiting bodies of Ganoderma lucidum at different growth stages were investigated. The polysaccharides contents and enzymes activities were determined with phenol-sulfuric acid method and spectrophotometry method, respectively, with bag-cultivated Ganoderma lucidum as test material. The results showed that, the change tendency of activities of three kinds of sugar metabolism-related enzymes(hexokinase,α-phosphoglucomutase and phosphoglucoisomerase) was similar to that of polysaccharides contents. The polysaccharides content was the lowest in the budding stage with the value of 11.7 mg/g.From the budding stage, the polysaccharides contents increased gradually with the increase of the related enzymes activities and reached the maximum value 23.3 mg/g before the spore powder ejection in the maturation stage, while the activities of hexokinase,α-phosphoglucomutase and phosphoglucoisomerase also reached the maximum values(23.9,25.1, 18.7 U/g), respectively. And then the polysaccharides contents decreased with the significant decrease of the related enzymes activities and the polysaccharides content was only 16.3 mg/g after spore ejection. There was a significant positive correlation between the polysaccharides content and the activities of sugar metabolism-related enzymes, which speculated that hexokinase,α-phosphoglucomutase and phosphoglucoisomerase were the key enzymes in the biosynthesis of Ganoderma lucidum fruiting body polysaccharides.