一株抗菌海洋真菌的筛选、鉴定与发酵条件优化

Screening,Identification,Optimization of Fermentation Conditions of an Antibacterial Obligate Marine Fungus COF01

从专性海洋真菌中筛选具有抗菌活性的菌株,并对其发酵条件进行优化.以Escherichia coli,Bacillus pumilus,Fusarium graminearum和Saccharomyces cerevisiae作为指示菌,利用管碟法从10株专性海洋真菌中筛选抗菌活性菌株,获得1株对革兰氏阳性细菌、革兰氏阴性细菌及多种植物病原真菌均有拮抗作用的菌株COF01,通过形态学与18SrDNA-ITS序列分析将该菌株鉴定为黑曲霉(Aspergillus niger);采用单因素试验和正交试验优化菌株产抗菌物质的发酵条件为玉米粉20g/L、黄豆粉15g/L、NaCl 3g/L,海水配制,在此条件下,发酵液粗提物对Fusarium vasinfectum抑菌圈直径达到(43.79±2.82)

The objective of present study is to screen an antibacterial obligate marine fungus, i- dentify and optimize its fermentation conditions. Activity plate assay was used to screen antibacterial fungi from ten obligate marine fungi strains with Escherichia coli, Bacillus pumilus, Fusarium graminearum, and Saccharomyces cerevisiae as test strains. Strain COF01 was primarily selected through activity plate assay and showed higher inhibitory against some pathogenic fungi. Strain COF01 was identified as Aspergillus niger by morphological and 18S rDNA-ITS gene sequence analysis. The medium contents were optimized through one-variable-at-a-time approach and orthogonal experiments. The optimum fermentation conditions for antibacterial substance production were as follows. 20 g/L corn flour, 15 g/L soybean flour, 3 g/L NaC1. In this condition, the antibacterial circle diameter is （43.79±2.82）mm.