海洋巨大芽孢杆菌抑制黄曲霉毒素的生物合成

Inhibitory effect on the aflatoxin biosynthesis by a strain of marine Bacillus megaterium

从海洋中分离筛选出一株巨大芽孢杆菌,在PDA平板上此株巨大芽孢杆菌可以显著抑制黄曲霉的生长,进而重点研究其对黄曲霉毒素合成的影响。结果表明,在液体培养基中此株海洋巨大芽孢杆菌极显著地抑制黄曲霉产黄曲霉毒素(p<0.01);另外研究发现,在受机械损伤的花生上,此株巨大芽孢杆菌也可显著抑制黄曲霉毒素的生物合成(p<0.05);而在没有机械损伤的花生上,此株芽孢杆菌没能表现出抑制毒素合成的能力。抑制机理初步认为,该株海洋巨大芽孢杆菌通过竞争性生长和产生某种次级代谢产物,抑制黄曲霉的生长和黄曲霉毒素合成基因的表达。

A strain of marine Bacillus megaterium was screened from the ocean. This strain of B. megaterium exhibited high inhibitory effect on the growth of Aspergillus flavus on PDA plates,so the inhibitory effect on the biosynthesis of aflatoxin was further studied. The results showed this strain of B. megaterium could significantly inhibit the biosynthesis of aflatoxin both in liquid medium（ p 0.01） and mechanical damaged peanuts（ p 0.05） , but didn’t exhibit inhibitory biosynthesis effect in intact peanuts. The primary inhibitory mechanisms were accredited to competitive growth and some kinds of metabolites secreted by this strain of B.megaterium which could inhibit the growth of A.flavus and expression of the genes relating to aflatoxin biosynthesis.