垂枝红千层内生真菌的分离鉴定及其生物活性

Isolation, Identification andBiological Activities of Endophytic Fungi from Callistemon viminalis

目的:研究垂枝红千层内生真菌的分离鉴定及其生物活性,为进一步发掘活性代谢产物奠定基础。方法:通过组织分离法分离培养垂枝红千层内生真菌,通过ITS序列分析对分离的真菌进行鉴定,并采用滤纸片法和SRB法对内生真菌的发酵液提取物进行抗菌和细胞毒活性研究。结果:共分离得到29个菌株,鉴定为17属20种,其中以黑孢霉属(Nigrospora)、间座壳属(Diaporthe)和刺盘孢属(Colletotrichum)为优势类群;菌株A797、A798和A809的发酵提取物,对金色葡萄球菌和枯草芽孢杆菌均具有较好抑制活性(抑菌圈直径≥13 mm);当发酵液提取物的作用浓度为100μg/mL时,菌株A781、A785和A805对4株受试肿瘤细胞均具有较明显的抑制作用(抑制率≥90%以上)。结论:垂枝红千层内生真菌多样性丰富,部分菌株具有较好的抗菌和细胞毒活性,值得进一步深入研究。

Objective To isolate and identify endophytic fungi from Callistemon viminalis and investigate their biological activities,thus providing a theoretical basis for further searchfor biologically activemetabolites.Method Endophyticfungiwereisolated and purified from C.viminalis by tissue isolation method and identified by analysis of ITS sequences.Antibacterial and cytotoxic activities of fermentation broth extracts of these endophytic fungi were examined by the filter paper dispersion method andthe Sulforhodamine B(SRB),respectively.Results 29 strains were isolated and identified as 20 species in 17 genera,among which Nigrospora,Diaporthe and Colletotrichum were the dominant genera.The fermentation extracts of strains A797,A798 and A809 showed inhibitory activity against Staphylococcus aureusand Escherichia coliwithinhibitionzone diameters of over 13 mm.The strains A781,A785 and A805 exhibited cytotoxic activity against the tested tumor cell lines with inhibitory rates of over 90%when the concentration of their fermentation extracts was 100μg/mL.Conclusion Endophytic fungi from C.viminalisare rich in diversity and several strains showed antibacterial and cytotoxic activities,which deserved further study.