玉米内生细菌YY1菌株高产抗菌物质的发酵条件优化

玉米内生细菌YY1菌株为枯草芽孢杆菌,对玉米大斑病菌(Setosphaeria turcica)有强烈的拮抗作用,通过产生抗菌物质发挥抑菌活性。以培养基的无菌滤液对玉米大斑病菌的拮抗活性为检测指标,确定其产生抗菌物质所需要的最佳碳源、氮源及无机盐,通过正交试验得到该菌株产生抗菌物质的培养基配方,并对其发酵工艺条件进行优化。结果表明,最佳培养基为可溶性淀粉3.0%,蛋白胨2.0%,KH2PO40.02%,MnCl20.01%。发酵工艺参数优化结果为培养基装液量30 mL/250 mL,接种量4%,培养基初始pH值为9.0,28℃条件下、120 r/min摇床振荡培养48 h。经发酵条件优化后,其抗菌活性有显著提高。

Optimization of Fermentation Conditions for High Production of Antimicrobial Substance by Entophytic Bacteria YY1 in Maize

The endophytic bacterium of maize Bacillus subtilis strain YY1 could produce antifungal substances to inhibit the growth of Setosphaeria turcica,which can cause north maize leaf blight.Measurement indicators were the inhibition activity of the sterile liquid supernatant.The optimal carbon source,nitrogen source and salt for the production of antimicrobial substance by strain YY1 were tested.The medium composition was optimized by orthogonal experiments.The fermentation technical and engineering parameters were also optimized.The results showed that the best medium compositions were amylodextrine 3.0%,peptone 2.0%,K2HPO4 0.02%,MnCl2 0.01%,and the optimum shaking flask fermentation condition were proper inoculation 4%,shaking flask volume at 30 mL/250 mL,120 r/min for 48 h under 28℃.The inhibition activity had a significant rise after fermentation condition optimization.