人参叶中高产皂苷菌种的筛选及培养条件优化

Screening of high-yield ginsenoside strains from ginseng leaves and culture conditions optimization

采用微生物发酵提取吉林不同产地(长白山、通化市榆林镇及白山市抚松县)人参叶皂苷,筛选适合发酵人参叶的最佳菌种,并研究料液比、发酵温度、接种量、初始pH值等因素对皂苷含量的影响,同时研究添加外源氮源、碳源、有机酸及磷盐等对发酵皂苷释放量的影响,确定最佳发酵条件及培养基成分。结果表明,最适的发酵菌种为酿酒酵母(Saccharomyces cerevisiae)CICC 31393,最佳发酵条件为料液比1∶10(g∶mL)、发酵温度30℃、接种量2.0%、初始pH值为5.0;最佳发酵培养基为蛋白胨+酵母粉(1∶1)1%、果糖2%、丙酮酸0.14%、磷酸氢二钾0.08%。在此优化条件下,3个不同产地人参叶发酵后总皂苷产量分别为194.25 mg/g、214.57 mg/g、271.75 mg/g。较未发酵组产量(64.11 mg/g、86.19 mg/g、106.91 mg/g)平均提高了约2.5倍。

The ginsenosides were extracted from ginseng leaves from different producing areas in Jilin(Changbai mountain,Yulin town in Tonghua,Fusong county in Baishan)by microbial fermentation,the optimal strains suitable for fermenting ginseng leaves were screened,and the effects of fermentation conditions such as material to liquid ratio,fermentation temperature,inoculum,and initial pH on the content of ginsenosides were studied.Meanwhile,the effects of the addition of exogenous nitrogen sources,carbon source,organic acids and phosphate salts on the release of ginsenosides were studied,and the optimal fermentation conditions and medium components were determined.The results showed that the optimal fermentation strain was Saccharomyces cerevisiae CICC 31393,the optimal fermentation conditions were material to liquid ratio 1∶10(g∶ml),fermentation temperature 30℃,inoculum 2.0%and initial pH value 5.0,and the optimal fermentation medium was peptone and yeast powder(1∶1)1%,fructose 2%,pyruvic acid 0.14%,and dipotassium phosphate 0.08%.Under these optimized conditions,the yield of the total ginsenosides from ginseng leaves from three different producing areas after fermentation were 194.25 mg/g,214.57 mg/g and 271.75 mg/g,respectively.Compared with the unfermented group(64.11 mg/g,86.19 mg/g,106.91 mg/g),the yields increased by about 2.5 times on average.