益生菌发酵制备金针菇抑菌肽

Preparation of Bacteriostatic Peptides from Flammulina velutipes by Fermentation of Probiotics

为获得更高产率的金针菇抑菌肽,该文优化益生菌固态发酵金针菇制备抑菌肽的最佳工艺条件,并采用超滤法对抑菌肽进行分级分离和活性比较。以金针菇为发酵基质,以抑菌肽对大肠杆菌、金黄色葡萄球菌和沙门氏菌的抑菌活性作为指标,对枯草芽孢杆菌、酿酒酵母和黑曲霉3种益生菌进行筛选,并优选出沉淀法分离抑菌肽的最适pH值,然后采用单因素和响应面试验考察液料比、发酵时间、发酵温度和金针菇用量4个因素对发酵制备金针菇抑菌肽产率的影响。结果显示:黑曲霉为固态发酵制备金针菇抑菌肽的最适菌种;沉淀抑菌肽的最适pH值为4;最佳发酵条件为液料比3.5∶1(mL/g)、发酵时间109.6 h、发酵温度28℃、金针菇用量27.21 g,在此条件下得到金针菇抑菌肽的产率为(61.25±1.14)%。截留分子量小于3 kDa的抑菌肽活性最强。

In order to obtain a higher yield of bacteriostatic peptides from Flammulina velutipes,this paper optimized the process conditions for preparing bacteriostatic peptides by solid-state fermentation of probiotics on F.velutipes,and used ultrafiltration to grade and compare the activity of bacteriostatic peptides.Using F.velutipes as the fermentation substrate,with the antimicrobial activity of the bacteriostatic peptides against Escherichia coli,Staphylococcus aureus,and Salmonella as the indicator,three probiotics including Bacillus subtilis,Saccharomyces cerevisiae and Aspergillus niger were screened,and the optimal pH value for separating and precipitating bacteriostatic peptides was selected.Then,the effects of four factors including liquid-to-solid ratio,fermentation time,fermentation temperature,and amount of F.velutipes on the yield of F.velutipes bacteriostatic peptides were investigated by single-factor and response surface experiments.The results showed that A.niger was the optimal strain for solid-state fermentation to produce F.velutipes bacteriostatic peptides.The optimal pH for precipitating bacteriostatic peptides was 4;the optimal fermentation conditions were as follows:liquid-to-solid ratio of 3.5∶1(mL/g),fermentation time of 109.6 h,fermentation temperature of 28℃,and amount of F.velutipes of 27.21 g.Under these conditions,the yield of F.velutipes bacteriostatic peptides was(61.25±1.14)%.Bacteriostatic peptides with a molecular weight less than 3 kDa had the strongest activity.