非脱羧勒克菌wt16对黄曲霉菌生长与产毒的抑制作用

黄曲霉菌及其毒素严重威胁农产品质量安全,本文旨在探寻非脱羧勒克菌对黄曲霉菌及其毒素污染防控效果。从湖北黄陂分离筛选出一株非脱梭勒克菌wt16,将其与黄曲霉菌在液体培养基中共培养后测定非脱羧勒克菌wt16菌株对黄曲霉菌生长及产毒的抑制率。结果表明,在沙氏液体培养基中,非脱羧勒克菌wt16能明显抑制黄曲霉菌的生长及产毒,对其菌丝生长的抑制率为77%~92%,对其产毒的抑制率为90%~96%。通过扫描电子显微镜观察发现,非脱羧勒克菌wt16能改变黄曲霉菌丝的形态,使得黄曲霉菌丝体由规则的球体聚集成不规则形状,单个菌丝会由细长型断裂成小截形态,菌丝表面也变得更为光滑;并且发现wt16在花生粉及未受机械损伤的花生颗粒上对黄曲霉菌的生长及产毒均表现出很强的抑制作用。进一步研究发现,非脱羧勒克菌wt16菌株发酵上清液中含有能抑制黄曲霉毒素合成的有效成分,且该发酵上清液的制备以培养4 d以上为最佳,培养温度为15~40 ℃。

Inhibition Effect of Leclercia Adecarboxylata Strain wt16 on the Growth and Aflatoxin Production of Aspergillus flavus

Aspergillus flavus and its aflatoxin seriously threated the quality and safety of agricultural products. This study was aimed to explore the effect of Leclercia adecarboxylata wt16 on Aspergillus flavus growth and producing aflatoxin. A strain of Leclercia adecarboxylata wt16 strain was screened from the Hubei Huangpi. The effect of wt16 on the growth of Aspergillus flavus and the aflatoxin production was studied through their coculture in the medium. The results showed that wt16 could significantly inhibit the growth of Aspergillus flavus and aflatoxin production in medium,the rate of wt16 for its growth inhibition was 77%~92%,the rate of wt16 for its aflatoxin production was 90%~96%. And wt16 could change the morphology of Aspergillus flavus by Scanning Electron Microscopy(SEM),it could change the mycelium of Aspergillus flavus into irregular shape,the slender mycelium could be breaked into small sectional shape,and its surface could become more smooth. It also played a same role in growth and aflatoxin production of Aspergillus flavus on peanuts. After the further studied,it was found that fermentation supernatant had the effective ingredient to inhibit aflatoxin synthesis. The results showed that the best incubation time of wt16 was more than 4 d,and the culture temperature was 15~40 ℃.