一株产毒素葡萄链格孢菌的分离及鉴定

Isolation and Identification of a Fungus Producing Mycotoxins from Grapes Fruits

链格孢菌是导致葡萄采后腐烂的一种重要病原菌,且其产生的真菌毒素会对人体健康造成安全隐患.本研究从自然发病的葡萄果实中分离纯化出一株侵染菌株(A-0913),根据真菌的形态学特征并结合5.8SrDNA-ITS基因序列分析确定该菌株属于链格孢菌(Alternaria alternata).同时,对该菌株基础生物学特性及其毒素检测的研究结果表明:该菌丝体最适生长温度为25℃,中性或偏碱性环境均有利于菌丝体的生长,PDA培养基中培养36h后可达对数生长期.研究发现该菌株具有产毒素的性能,通过进一步优化真菌毒素HPLC检测条件发现该链格孢菌株主要产AOH和AME两种真菌毒素.

Alternaria alternata is a common pathogen causing grapes postharvest decay,the producing mycotoxins will cause safe hazards to human health.In this study,the strain（A-0913）was isolated from the surface of rotten redglobe table grapes fruit and purified in PDA medium.According to the results of morphological characterization and 5.8SrDNA-ITS gene sequence analysis,A-0913 was identified as A.alternata.Meanwhile,we have explored the basic biological characteristics of the strain and detection methods of toxin.The experiment results showed that the logarithmic growth phase of A-0913 was reached at 36 h,the optimal growth temperature for the mycelium was 25 ℃,and the neutral or low alkaline cultre conditinos were favorable for the growth of the mycelium.Further expriment showed that two of the most common A.alternata mycotoxins（alternariol and alternariol monomethyl ether）were detected in this strain after extraction.