隐板裸刺蛇尾共附生真菌的分离鉴定及其代谢产物的抑菌活性研究

Isolation and Identification of Symbiotic or Epiphytic Fungi from Gymnolophus obscura and Study on the Antibacterial Activity of Their Metabolites

为更好地开发和利用蛇尾共附生微生物资源,本研究对隐板裸刺蛇尾(Gymnolophus obscura)可培养共附生真菌及其代谢产物抑菌活性进行研究。实验采用3种培养基分离隐板裸刺蛇尾共附生真菌,通过Blast分析ITS rDNA基因序列鉴定真菌,并运用96孔板法评估真菌的乙酸乙酯提取物的抑菌活性。实验结果发现,从隐板裸刺蛇尾分离的共附生真菌有格孢腔菌目(Pleosporales)真菌7株和肉座菌目(Hypocreales)真菌4株。两株真菌(GXIMD02021和GXIMD02022)与已报道菌株的ITS rDNA序列相似度小于97%,是潜在新菌种,占已鉴定菌株数量的18.2%。所有共附生真菌代谢产物对至少一种指示菌有抑制活性。除GXIMD02019、GXIMD02020、GXIMD02022和GXIMD02023外,其他菌株代谢产物均抑制表皮葡萄球菌(Staphylococcus epidermidis);4株菌株(GXIMD02018、GXIMD02020、GXIMD02021和GXIMD02022)代谢产物抑制耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus aureus);3株菌株(GXIMD02021、GXIMD02022和GXIMD02024)代谢产物抑制铜绿假单胞菌(Pseudomona aeruginosa);9株菌株(GXIMD02017和GXIMD02021除外)代谢产物抑制Actinomyces viscosus。本研究表明隐板裸刺蛇尾共附生真菌中潜在新菌占比较高,丰富了棘皮动物共附生真菌的多样性,为隐板裸刺蛇尾共附生真菌次级代谢产物及其生物活性研究提供了菌种。

In order to better develop and utilize the symbiotic microbial resources of Gymnolophus obscura,the antimicrobial activities of culturable symbiotic and epiphytic fungi and their metabolites from G.obscura were studied in this study.Three media were used to isolate the symbiotic or epiphytic fungi from G.obscura.Fungi isolated from G.obscura were identified based on the analysis ITS rDNA gene sequences in the Blast database.The antibacterial activity of their metabolites was evaluated by 96 well plate method.The results showed that 7 strains of Pleosporales and 4 strains of Hypocreales were isolated from the symbiotic or epiphytic fungi.The ITS rDNA sequences of two fungi(GXIMD02021 and GXIMD02022)were less than 97%similar to the reported strains,which were potential new strains,accounting for 18.2%of the identified strains.All the metabolites of symbiotic or epiphytic fungi had inhibitory activity against at least one indicator bacteria.Except for GXIMD02019,GXIMD02020,GXIMD02022 and GXIMD02023,the metabolites of other strains inhibited Staphylococcus epidermidis.The metabolites of 4 strains(GXIMD02018,GXIMD02020,GXIMD02021 and GXIMD02022)inhibited Methicillin resistant Staphylococcus aureus.The metabolites of 3 strains(GXIMD02021,GXIMD02022 and GXIMD02024)inhibited Pseudomona aeruginosa.The metabolites of 9 strains(except GXIMD02017 and GXIMD02021)inhibited Actinomyces viscosus.This study showed that the proportion of potential new taxa is relatively high in symbiotic or epiphytic fungi of G.obscura,which further enriched the diversity of symbiotic or epiphytic fungi of echinoderm,and provided strains for the study of secondary metabolites and biological activities of symbiotic or epiphytic fungi of G.obscura.