盐生海芦笋内生真菌S19的分离鉴定与抗氧化发酵条件优化

Isolation and identification of an endophytic fungus strain S19 from Salicornia bigelovii and optimization of its antioxidative fermentation conditions

以盐生海芦笋中分离的1株内生真菌S19菌株为研究对象,对ITS区域序列进行PCR扩增测序并进行系统发育分析,结合形态学观察,将其鉴定为Gibberella avenacea。采用Plackett-Burman试验、最陡爬坡试验和响应曲面法对S19菌株的发酵条件进行优化,最大限度地提高其抗氧化活性。优化后的最佳培养基配方为:16 g.L-酵母膏,17 g.L-1蛋白胨,300g.L-1土豆,30 g.L-1麦芽糖,30 g.L-1甘露醇,5 g.L-1葡萄糖,10 g.L-1味精,10 g.L-1氯化钠,pH为7。采用此培养基所得发酵产物对2,2-二苯基-1-苦肼基(DPPH)自由基的最大清除率为78.25%,比优化前(清除率66.55%)有显著提高。

An endophytic fungus strain S19 isolated from Salicornia bigelovii was used as the material. It was identified as Gibberella avenacea by ITS rDNA sequencing and phylogenetic analysis combined with morphological observation. The fermentation conditions of S19 were optimized by using the Plackett-Burman, the steepest hill-climbing experiment and the response surface method, to maximize its antioxidant activity. The optimum medium was as follows ： 16 g·L^-1 yeast extract, 17 g·L^-1 peptone, 300 g·L^-1 potato, 30 g·L^-1 maltose,30 g·L^-1 mannitol,5 g·L^-1glueose,10g·L^-1 monosodium glutamate and 10g·L^-1 sodium ehloride,pH 7. Using the optimum culture medium,the maximum DPPH free radical scavenging rate of the fermentation products was 78.25% ,which was sig- nificantly higher than before（66.55% ）.