响应面法优化重组AhPR-1蛋白抑制黄曲霉菌侵染花生的条件

Optimized Factors of Recombinant PR-1 Protein on Peanut Defensing Aspergillus flavus

基于大肠杆菌重组花生Ah PR-1蛋白具有抑菌的作用功能,利用响应面法优化蛋白抑制黄曲霉菌在花生上生长的条件因素。以表观评价法测评的黄曲霉生长程度和HPLC法检测的毒素合成的含量为评价标准,考察Ah PR-1蛋白质量浓度、作用温度和水分活度对蛋白抑制黄曲霉菌侵染花生及黄曲霉毒素产生的影响。结果显示,在花生染黄曲霉菌浓度为4×10^6CFU/m L的条件下,随着蛋白质量浓度升高,抑菌效果明显增强,蛋白质量浓度为0.32 ng/μL和0.40 ng/μL,效果最好且差别不是很明显;在温度28℃,水分活度0.3-0.4的条件下,AhPR-1蛋白的抑制效果最显著。在一定的环境条件下,Ah PR-1蛋白能够一定程度上抑制黄曲霉菌在花生表面的繁殖生长和毒素的合成。

Based on the inhibiting function of recombinant Ah PR-1 protein in E. coli against microbe, environmental factors of protein inhibiting A. flavus growth on peanut were optimized by using surface response method. The inhibiting effects of Ah PR-1 on peanut, including protein concentration, temperature and water activity, were estimated using apparent evaluation method on A. flavus growth level and HPLC on aflatoxin production. Results show that, when inoculated with 4 ×10^6CFU/m L spore suspension of A. flavus NRRL 3357 on peanut, the resistance effect of PR-1 increased with the concentration protein, while there was no significant difference of inhibition effect between 0.32 ng/μL and 0.40ng/μL of PR-1 protein, respectively; in the same time the inhibition effect of PR-1 protein reached its peak under 0.3-0.4 water activity at 28 ℃. Thus, growth A. flavus and aflatoxin synthesis on peanut could be suppressed to some level by PR-1 protein under certain environmental circumstances.