解淀粉芽孢杆菌F1对黄曲霉的拮抗条件优化及其抑霉特性研究

Condition optimization for antagonizing of Bacillus amyloliquefaciens F1 against Aspergillus flavus and its mycostatic properties

研究室前期从市售黑胡椒表面分离鉴定了1株解淀粉芽孢杆菌Bacillus amyloliquefaciens F1(保藏号:CGMCC No.10942),研究发现该菌株能产生抗真菌蛋白,对黄曲霉具有较强的抑制作用。该研究拟在前期基础上,通过单因素试验优化B.amyloliquefaciens F1的培养条件及培养基组分,进一步增强其对黄曲霉的拮抗效果,并考察B.amyloliquefaciens F1发酵液对黄曲霉生长及产毒的影响。结果表明,B.amyloliquefaciens F1拮抗黄曲霉的适宜培养条件:为温度32℃,初始p H值5.5,培养时间48 h;适宜发酵培养基为在营养肉汤培养基中添加0.4%蔗糖、0.2%柠檬酸铵和0.02%KNO_3。优化后F1发酵上清液对黄曲霉的抑菌率达到75.2%,比优化前提高了60.1%。进一步的研究发现,B.amyloliquefaciens F1的发酵上清超滤液(30 k^100 ku)能够抑制黄曲霉孢子萌发、延缓菌丝发育,在蛋白质量浓度为0.1 mg/m L时能完全抑制黄曲霉毒素的产生。

In our precious study,a strain was isolated from the surface of the commercial black pepper and identified as Bacillus amyloliquefaciens,named as B. amyloliquefaciens F1（ Preservation number： CGMCC No. 10942）,and the study found that the strain could produce antifungal protein and had stronger inhibition effect on Aspergillus flavus. Based on the precious study,culture condition and media components of B. Amyloliquefaciens F1,for further strengthening its inhibitory effect on Aspergillus flavus,were optimized through single factor tests,and the effect of fermentation broth of the strain on growth and toxin production of Aspergillus flavus was investigated. The results showed that the optimum culture conditions of B. amyloliquefaciens F1 for inhibiting Aspergillus flavus were temperature 32 ℃,initial p H value 5. 5 and culture time 48 h,and the suitable fermentation broth was nutrient broth medium added0. 4% sucrose,0. 2% ammonium citrate and 0. 02% potassium nitrate. After optimization,the inhibition rate of fermentation supernatant of the strain F1 on Aspergillus flavus reached 75. 2%,which was 60. 1% higher than before optimization. Further research found that ultrafiltrate（ 30 k- 100 ku） of fermentation supernatant of B. amyloliquefaciens F1 could inhibit germination of Aspergillus flavus,slow growth of Aspergillus flavus hypha,and completely inhibit production of aflatoxin when the protein concentration was at 0. 1 mg / m L. The study provide data reference for applications of B. amyloliquefaciens F1 as biocontrol bacterium in food area.