北极海泥来源抗菌活性真菌的筛选及菌株H5的初步研究

Screening of Antimicrobial Marine Fungus from Sea Soil in the Arctic and Preliminary Study of Active Strain H5

从北极海泥中筛选抗菌活性海洋真菌,鉴定了活性菌株并对活性最高的菌株H5的代谢产物进行了初步研究。通过形态学观察、基因间隔区(ITS)序列分析对活性最高的菌株H5进行系统发育分析和菌种鉴定;通过纸片法对菌株H5的发酵液进行体外抗菌活性研究;将调至不同pH值的H5发酵液用不同极性的有机溶剂萃取,研究该活性物质的酸碱性和极性;将调至不同pH值的发酵液按不同时间温度梯度进行加热处理,研究该活性物质的稳定性;同时用大孔树脂对活性物质进行提取分离。结果表明,从北极海泥中共分离得到17株真菌,其中真菌H5、H6的代谢产物具有较好的抗菌活性;菌种鉴定表明菌株H5归属于烟曲霉属(Aspergillus fumigatus),该菌株发酵液对革兰氏阳性菌、革兰氏阴性菌、真菌及耐药菌均有不同程度的抑制活性,活性产物为极性较大、热稳定性较好、耐酸不耐碱的物质;薄层层析显示活性成分在254nm紫外光下无吸收。

We screened marine fungus with antimicrobial activity,identified strains with better activity and studied bioactive metabolites produced by marine fungi H5 with the highest activity. According to the morpho- logical characteristics and internal transcribed spacer（ITS） sequence phylogenetic analysis,strain H5 was iden- tified. The pH value stability,thermostability,and the polarity of the antibiotics of strain H5 were measured by the paper disc diffusion assay, meanwhile the bioactive ingredients were separated by macroporous resin. The result showed that 17 strains of fungus were isolated from sea soil in the Arctic,among which strains H5 and H6 showed antimicrobial activity,the strain H5 was identified to be Aspergillusfumigatus ,its broth had differ- ent antimicrobial activities against gram-positive bacteria, gram-negative bacteria, fungus and drug-resistant strains and the bioactive metabolites had strong polarity,better heat and acid stability,the samples of crude ex- tract had fluorescence tape by TLC and the active component showed no signal under UV light.