一株野生桑黄的分离鉴定与生物学特性

Isolation, identification, and biological characterization of a wild Sanghuang mushroom

桑黄是我国传统名贵的药用真菌,在分类学上是锈革孔菌科(Hymenochaetaceae)几种药用真菌的总称.从北京延庆区四海镇黑汉岭采集到一株桑黄子实体,经分离纯化获得纯培养(编号SS).进一步开展其分类鉴定、最适培养条件和液体发酵产物活性研究.根据ITS鉴定,确定SS菌株属于锈革孔菌科针层孔菌属(Phellinus),与苹果木层孔菌(Phellinus tuberculosus)的相似性为95%;结合子实体、菌丝特征和寄主植物类型,确定SS菌株为苹果木层孔菌.SS菌株菌丝体最适培养条件研究表明,其最适碳源为葡萄糖,最适氮源为黄豆粉,最适C/N比为20/1,最适生长因子为维生素C,最适温度为28℃,最适pH为7.0.以马铃薯葡萄糖液体(PD)培养基、10%接种量、28℃、150 r/min培养7 d,发酵液中多糖含量为176.71 mg/L,黄酮含量为0.11 mg/L,抗氧化活性为7.82 mol/L(FeSO_4),未检测到多酚的存在.本研究从野外获取新的桑黄药用资源,其生物学特性结果可为野生药用真菌的人工驯化和开发利用提供理论依据.

Sanghuang is a famous traditional Chinese medicinal fungus and a generic term of medicinal mushroom species taxonomically belonging to the family Hymenochaetaceae. In the present study, fruiting bodies of a wild Sanghuang species were collected from the Heihan Mountain, Sihai Town, Yanqing District, Beijing. Pure culture strain was obtained and numbered as SS. We then studied its classification, optimum culture conditions, and bioactivities of fermentation broth. Morphology and ITS identification showed it as a polypores fungus of genus Phellinus and family Hymenochaetaceae. Strain SS manifested high sequence similarity of 95% with Phellinus tuberculosus based on ITS identification, and was further classified as P. tuberculosus based on its morphological characteristics of fruiting bodies, mycelia, and the host plant. Culture conditions study showed the optimum condition for the mycelia growth included glucose as the carbon source, soybean powder as the nitrogen source, the C/N rate of 20/1, growth factor as Vitamin C, temperature as 28 ℃, and pH as 7.0. After incubation in potato dextrose （PD） medium, 10% inoculation amount, 28℃ and 150 r/min for 7 d in the shaking flask, fermentation broth of strain SS was harvested. Crude polysaccharides and flavonoids of fermentation broth were evaluated to be 176.71 mg/L and 0.11 mg/L, respectively. Total antioxidant activity was 7.82 mol/L （FeSO4）. Polyphenol was not found in the fermentation broth. It suggested that the newly obtained fungal species demonstrates potential application in medicine industry. It is an important reference for further artificial domestic cultivation and applications of the medicinal mushroom resources.