草莓致腐霉菌的鉴定及其产毒能力研究

目的调查草莓表面主要致腐真菌,并研究其是否产生毒素。方法对草莓真菌进行分离,综合利用菌落形态学观察、显微生殖观察、真菌ITS序列系统发育学分析鉴定真菌;利用高效液相色谱法检测腐烂草莓及真菌发酵液中赭曲霉毒素A(ochratoxin A,OTA)的含量。结果 4种毛霉属真菌和1种青霉属真菌可引起草莓腐烂,经分子鉴定分别为易脆毛霉菌、卷枝毛霉菌、多枝毛霉菌、根毛霉菌和草酸青霉菌。腐烂的草莓和毛霉发酵液检测不出OTA,但青霉菌发酵液中检测出OAT毒素存在。结论真菌是致草莓腐烂的主要诱因,毛霉菌在腐烂过程中占主导地位,但产毒素的青霉菌与其共生,应加强草莓及制品的风险监测。

Identification and toxin-producing capability of causing-spoilage fungi in strawberry

Objective To Research the main causing -spoilage fungi on the surface of strawberries and analyze whether it generates toxins. Methods The fungi were isolated and purified from strawberries. Taxonomic status of fungi was conducted by colony morphology observation reproduction microscopic observation and phylogenetic analysis based on the ITS gene sequence. High performance liquid chromatography (HCLP) was used to detect the content of ochratoxin A(OTA) in spoilage strawberries and fungal fermentation broth. Results Four kinds of Mucor and one penicillium which could cause strawberry decay were identified on molecular level as aseptic mold, Mucor fragilis, Mucor circinelloides, Mucor racemosus, Rhizomucor variabilis and Penicillium sp.. OTA could not be detected form spoilage strawberries and fungal fermentation broth , but OAT toxins was detected in Penicillium fermentation broth. Conclusion Fungi were the main cause of strawberry rot and the mold played a dominated role in the decay process, but Penicillium which produced toxins coexisted with it. Monitoring should be strengthened on the risk of strawberry and its products.