一种野生多孔菌的分离、鉴定、培养条件及抗氧化活性

Isolation, identification, optimal cultivation conditions and antioxidant activity of a wild polypore

多孔菌是一类子实体呈孔状且质地为革质至木质的大型担子菌,其中一部分具有较高的药用价值.对一株野生多孔菌子实体进行分离纯化获得纯培养BJ菌株,并对其分类、最适培养条件和液体发酵产物抗氧化活性进行分析.采用形态学和ITS分类学鉴定菌株的分类学地位;通过测定菌株在不同碳源、氮源等培养基中的生长状况,研究菌丝最适培养条件;使用2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)法测定菌株发酵液总抗氧化活性;使用总超氧化物歧化酶(T-SOD)法、1,1-二苯基-2-苦基肼基自由基(DPPH)法测定菌株发酵液菌体的总超氧化物歧化酶活力和自由基清除能力.结果显示:经鉴定BJ菌株为石榴嗜蓝孢孔菌(Fomitiporia punicata).菌丝体最适培养碳源为葡萄糖、麦芽糖和淀粉,最适氮源为酵母浸粉,最适C/N比为10/1,最适温度为28℃,最适pH为7.0.发酵液总抗氧化活性为0.517 mmol/L(维生素E),菌体的总超氧化物歧化酶活力为770.37 U/g,DPPH自由基清除力的IC_(50)为2.14 mg/mL.本研究从野外获取了一株高抗氧化活性的药用多孔菌资源,可为野生药用真菌的开发利用提供理论依据.

Polypores are a group of macro-basidiomycetes with poroid hymenophore and corky basidiocarps that are widely distributed all over the world. Some of polypores have high medicinal value. In the present study, a pure culture fungal strain BJ was obtained from fruiting bodies of a wild polypore species. Further studies were investigated including classification, optimal culture conditions, and antioxidant activity of fermentation broth. Classification of this strain was performed using morphological and ITS identification. Optimal culture conditions of mycelia were evaluated based on their growth in different media. Total antioxidant activity of fermentation broth was assayed using the ABTS methods. Total superoxide dismutase and radical scavenging activities were determined with the T-SOD and DPPH methods, respectively. Strain BJ was classified as Fomitiporia punicata. Culture conditions showed that the best carbon sources was glucose, maltose, and starch; the best nitrogen source was yeast extract; the best C/N ratio was 10/1; the optimal temperature was 28 °C; and the optimal p H was 7.0. Total antioxidant activity of fermentation broth was 0.517 m M towards Trolox. Total superoxide dismutase and IC_（50） of radical scavenging activities were 770.37 U/g and 2.14 mg/m L, respectively. This research obtained new fungal strain with antioxidant activity, and could be an important reference for further applications of the medicinal mushroom resources.