一株南海指海绵共附生真菌多样性及其抗菌活性

本研究通过采用6种不同的培养基对南海指海绵上的共附生真菌进行平板涂布法分离培养,结合ITS-rDNA基因序列特征和形态学特征进行鉴定来研究海绵共附生真菌多样性。共分离培养出55株(21种)真菌菌株,优势菌属为木霉菌属Trichoderma sp.(31株),其中的哈茨木霉Trichoderma harzianum 22株作为优势菌种,占真菌菌株总数的40%。其余真菌则属于枝孢菌属Cladosporium、迈耶氏酵母属Meyerozyma、茎点霉属Phoma、红酵母属Rhodotorula、青霉菌属Penicillium、曲霉属Aspergillus等10个属,还有两株未鉴定到种的子囊菌。选取金黄色葡萄球菌Staphylococcus aureus等7种病原指示菌,采用琼脂扩散法对21种真菌的代表性菌株进行抗菌活性筛选,其中有3种真菌至少对一种指示菌表现出抑菌效果,占菌株种类总数的11%。

Diversity and antibacterial activities of fungi associated with the South China Sea sponge

Six different kinds of culture media are used to isolate and cultivate the fungi associated with the South China Sea sponge. The isolates obtained totaled 55, belonging to 22 species. The identification was made through morphological observation in combination with ITS-rDNA blast homology analysis. The dominant genus is Trichoderma (31 isolates), and Trichoderma harzianum is dominant species (22 isolates), accounting for 40% of the total number of isolates. The remainder belongs to Cladosporium, Meyerozyma, Rhodotorula, Microsphaeropsis, Penicillium, Aspergillus, Phoma, Candida, Pestalotiopsis, and Engyodontium. Besides, two ascomycete isolates are unidentified. Seven indicator bacteria including Staphylococcus aureus were selected for antibacterial activity test. By using agar diffusion method, the bacteriostatic effect of the fungal isolates was verified. The result demonstrated that three isolates showed antibacterial activity for at least an indicator bacteria.