小豆内生真菌的筛选鉴定及其产玉米赤霉烯酮的可能性探究

玉米赤霉烯酮(zearalenone,ZEN)是目前全球范围污染谷物最广泛的霉菌毒素之一,对人体和动物健康都会产生极大威胁,目前从市售小豆检测到ZEN。【目的】筛选暴露ZEN的小豆内生真菌,结合经典方法和分子生物学方法鉴定所筛选内生真菌,并探索菌株潜在的ZEN产生风险。【方法】以暴露ZEN的小豆为样本,将分离纯化后的内生真菌进行经典形态观察；同时扩增真菌核糖体保守序列ITS1、ITS4,镰刀菌特异基因序列FU1、FU2确定小豆中镰刀菌种属,同时通过ZEN玉米赤霉烯酮产毒控制基因pks13进行PCR扩增,分析菌株ZEN合成的潜在风险。【结果】鉴别出3株镰刀菌,其中2株初步鉴定为砖红镰刀菌(Fusarium lateritium)、1株为花腐镰刀菌(Fusarium napiforme),未检测出ZEN合成关键基因；1株玛利节菱孢霉(Arthrinium marii),分子检测具有产ZEN玉米赤霉烯酮毒素的可能性。将以上4株菌分别回接至ZEN的产毒培养基,LC-MS/MS法未检测出ZEN毒素。【结论】暴露ZEN的小豆具有内生镰刀菌,存在可能产ZEN的内生节菱孢霉；回接培养基未检测到ZEN,但不排除小豆产生ZEN的风险。

Screening and identification of endophytic fungi of Vigna angularis and investigation of its potential to produce zearalenone

Objective] The aim is to screen endophytic fungi of adzuki bean exposed to ZEN, and to detect the potential ZEN production risks of the screened strains by using classical culture toxin production and molecular biology methods. Methods] Taking adzuki bean exposed to ZEN as a sample.The isolated and purified endophytic fungi were subjected to classical morphological observation, and the fungal ribosomal conserved sequences ITS1 and ITS4 and Fusarium-specific gene sequences FU1 and FU2 were amplified to determine the Fusarium species in the beans, while the ZEN production control pks13 was amplified by PCR to analyze the potential risk of ZEN synthesis in the strains . Results] The results show that three Fusarium strains were identified, of which two were preliminarily identified as Fusarium lateritium and one as Fusarium napiforme. One strain of Arthriniummarii has the possibility of producing zearalenone toxin by molecular detection. The above four strains were spliced back into the media supplemented with adzuki beans flour, and adzuki bean component toxigenic culture medium respectively, and no toxin was detected. Conclusion] It was found that ZEN-producing endophytic fungi may exist in adzuki bean of ZEN, but ZEN was not detected in culture of toxic medium. The culture conditions for inducing virulent strains to produce ZEN still need to be further optimized.