2株耐热真菌的分离鉴定及其产酶活性研究

Isolation,Identification and Enzyme Activities of Two Thermotolerant Fungi

【目的】对新疆玛纳斯火烧洼热气泉土壤样品中,分离出的2株耐热真菌MHS7和MHS9进行鉴定,并研究其产酶活性。【方法】利用平板稀释涂布法分离筛选耐热真菌,基于菌株形态学特征和r DNA ITS序列分析,对分离得到的耐热真菌菌株进行初步分类鉴定;分别测定各菌株产淀粉酶、蛋白酶、纤维素酶、脂肪酶、木聚糖酶和糖苷酶的能力。【结果】得到2株耐热真菌MHS7和MHS9,初步鉴定菌株MHS7属于小裸囊菌属(Gymnascella),菌株MHS9属于曲霉属(Aspergillus)。产酶活性检测表明,菌株MHS7和MHS9均能产淀粉酶、蛋白酶、纤维素酶和脂肪酶,其中,菌株MHS9产淀粉酶和蛋白酶的活性相对较高。【结论】耐热真菌MHS7和MHS9均能同时产四种酶,具有潜在的应用价值。

【 Objective】 This project aims to have a preliminary identification of the two thermotolerant fungi MHS7 and MHS9 isolated from a hot gas spring in Manasi County of Xining and study their enzyme activ- ities.【 Method]Thermotolerant fungi were isolated and screened by using a agar dilution method, and the pri-mary identification was studied according to cultural characteristics and rDNA ITS （ Internal Transcribed Spac-er） sequences analysis. The amylase, protease, cellulose, lipase, xylanase and glycosidase were detected on six special selective media for thermotolerant fungus strains with the enzyme activity.【 Result】 Two strains of thermotolerant fungi named MHS7 and MHS9 were isolated. ITS sequence analysis identified that the strain MHS7 belonged to Gyrrmascella sp. , and the strain MHS9 was Eurotium sp. . Studies on enzyme - producing activities of strains MHS7 and MHS9 indicated that both of them produced amylase, protease, cellulose, and lipase. Of the two, the strain MHS9 had higher levels of amylase and protease activities than the strain MHS7.【 Conclusion】 The thermotolerant fungi MHS7 and MHS9 had complex enzyme activities and might have poten-tial application value.