厦门杏林湾红树林根际真菌分离及活性分析

【背景】海洋微生物是天然药物资源宝库,海洋环境中的微生物能够产生很多区别于陆生微生物的天然产物。红树林生长于陆地与海洋交界带的滩涂浅滩,是陆地向海洋过渡的特殊生态系统,可能蕴含着丰富的微生物资源和潜在的大量结构新颖的代谢产物。【目的】以厦门杏林湾红树林根际海泥和海水为研究对象,探索其中可培养海洋真菌的多样性及其发酵提取物的抗细菌和抗真菌活性,以期为发现新的药物先导化合物提供菌株资源。【方法】样品预处理后涂布于GPY、PDA、Martin和MEA这4种培养基,28℃倒置培养,待培养基上长出合适大小的菌落后,挑取单菌落接种于PDA培养基纯化。利用纸片扩散法对发酵提取物进行抗菌活性筛选,通过高效液相色谱分析提取物的化学多样性,并采用形态观察结合rDNAITS序列分析对活性较好的4株真菌进行菌种鉴定。【结果】共分离出71株真菌,其中49株真菌对金黄色葡萄球菌有抗性,6株真菌对白色念珠菌有抗性,2株真菌对大肠杆菌有抗性,菌株HS5-MEA-4和HS6-MEA-10初步鉴定为土曲霉,菌株HS5-GPY-7和HS6-GPY-15分别为棘孢曲霉和Aspergillus templicola。【结论】初步认知了厦门杏林湾红树林环境真菌多样性及其发酵提取物的活性和化学多样性特征,为后续海洋真菌次级代谢产物研究提供了依据。

Isolation and activity analysis of fungi from the rhizosphere of mangroves in Xinglin Bay, Xiamen

Background] Marine microorganism is a treasure pool of natural medicine resources. Marine microorganisms produced many natural products that are different from those produced by terrestrial microorganisms. Mangroves grow in tidal flats at the junction of land and ocean, it is a special ecosystem transitioning from land to ocean, and may contains abundant microbial resources and potentially a large number of metabolites with novel structures. Objective] This study takes sea mud and sea water from the rhizosphere of mangroves in Xinglin Bay, Xiamen as the research object, to explore the diversity of culturable marine fungi and the antibacterial and antifungal activities of the extracts, to provide strain resources for the discovery of new drug lead compounds. Methods] After pretreatment, the samples were coated on GPY, PDA, Martin and MEA media respectively, and were cultured upside down at 28 °C. Single colonies were selected and inoculated in PDA media to yield fungal strains. The antimicrobial activity of the extracts of the isolated fungi were screened by disk diffusion test and the biodiversity of the crude extracts were evaluated by high performance liquid chromatography, and four active fungi were identified by colony morphology and rDNA ITS sequence analysis. Results] A total of 71 fungi were isolated, 49 of which showed bioactivity against Staphylococcus aureus, 6 against Candida albicans and 2 against Escherichia coli. HS5-MEA-4 and HS6-MEA-10 were identified as Aspergillus terreus, HS5-GPY-7 and HS6-GPY-15 were identified as Aspergillus aculeatus and Aspergillus templicola, respectively. Conclusion] The activity characteristics of fungal extracts from the marine sedimentary environment of Xinglin Bay, Xiamen were preliminarily revealed, which provides resources for the subsequent biodiversity of antibacterial and antifungal secondary metabolites.