黄曲霉毒素B1降解菌的筛选及在玉米贮藏中的应用

Screening and application of an antagonistic bacterium against Aspergillus flavus

摘要:

[目的]本研究分离筛选出一株对黄曲霉既有抑制作用又能降解其毒素的拮抗细菌菌株，并将其应用于玉米中的黄曲霉污染防治研究。[方法]试验通过平板筛选法结合玉米活体筛选法对黄曲霉毒素B1（AFB1）的拮抗细菌进行初筛，以AFB1的降解率和抑制率为指标进行复筛。[结果]分离到的菌株对黄曲霉菌的抑制率为79.20%，对1 μg/mL的黄曲霉毒素B1的降解率为68.39%。贮藏期玉米含水量在15%-30%时，该菌株对黄曲霉污染的抑制率与玉米含水量成反比，即玉米含水量在15%时其抑制率达92.46%，玉米含水量在30%时其抑制率为19.41%。玉米含水量在28%时，菌株对黄曲霉污染玉米的防治效果达到36.39%。[结论]筛选出的拮抗菌株为枯草芽孢杆菌，该菌株不仅对黄曲霉菌有抑制作用，而且能减少AFB1对玉米的污染。

Abstract:

[Objective] We isolated bacterial strain that can antagonize the aflatoxin B1 (AFB1) producing fungus Aspergillus flavus in maize seed.[Methods] The plate method and in vivo screening were performed for samples from various sources. The positive bacterial strains were screened by their ability to degrade AFB1 in culture media.[Results] The inhibitory rate of bacterial strain to Aspergillus flavus was 79.2% and its degradation rate was 68.39% in 1 μg/mL AFB1. During storage period, the inhibition rate of the bacterial strain to Aspergillus flavus was inversely proportional to the water content of maize. When the water content in the maize was 15%, 92.46% inhibition rate was recorded, while the inhibition rate of 19.41% was noted with 30% water content in maize. When the maize water content was 28%, the control effect on Aspergillus flavus was 36.39%.[Conclusion] An AFB1-degrading strain not only could inhibit the growth of Aspergillus flavus, but also may control the contamination of AFB1 to maize.