产生物碱的甘肃贝母内生真菌的筛选、鉴定及抑菌活性测定

为了探索甘肃贝母(Fritillaria przewalskii Maxim.)内生真菌的应用价值,以甘肃贝母为材料,研究其内生真菌生物碱类代谢产物的多样性及抑菌活性。利用生物碱沉淀反应和薄层色谱技术(thinlayer chromatograph TLC)检测生物碱类成分,依据平板打孔法测定其抑菌活性,结合形态特征和内转录间隔区(internal transcribed spacer ITS)序列鉴定菌株。从甘肃贝母的健康鳞茎中分离得到13株内生真菌,其中,菌株G6能产生多种生物碱物质。但薄层色谱分析表明,菌株G6代谢的生物碱成分与川贝类生物碱并不一致。测定其抑菌活性发现,总生物碱提取液对金黄色葡萄球菌有显著的抑制效果而对粪肠球菌的抑制作用中等。结合形态学特征及ITS序列信息,菌株G6被鉴定为镰刀菌属接骨木镰刀菌(Fusarium sambucinum)。虽然菌株G6并不能产生与寄主相同的生物碱物质,但其在新生物碱及抑菌化合物的开发利用方面具有一定的价值。

Isolation,Identification and Antibiotic Activity of Alkaloid-producing Endophytic Fungi from Fritillaria przewalskii Maxim.

The aim was to reveal the potential value of the endophytes in Fritillaria przewalskii Maxim.,diversity and bioactivities of alkaloid-metabolites derived from endophytic fungus were studied.Alkaloids from the fermentation products of endophytic fungus were detected by Dragendorff ’ s and thin layer chromatography （TLC）.The agar-well diffusion method was applied to test the antibiotic activities.The screened strain was classified by morphological features combining with sequencing of internal transcribed spacer sequences （ITS）.There were thirteen endophytes isolated from the healthy bulbs of F.przewalskii,of them the strain G6 had the ability to produce several alkaloid components.However,according to the TLC analysis,these alkaloids from strain G6 were not identical with standard substances or those from bulbus Fritillariae Cirrhosae.The crude extract of alkaloids played a positive role in inhibiting the growth of Staphyloccocus aureus and Enterococcus faecalis,significantly and moderately,respectively.With the help of morphological features and the information contained by ITS sequences,the strain G6 was identified as Fusarium sambbucinum.On the basis of above factors,it was most likely that the strain G6 had wide prospect as a kind of donor source in exploiting new antibiotic substances and novel alkaloids,even though it could not produce the associated-plant alkaloids.