发酵谷物中产L-赖氨酸益生菌的筛选与鉴定

Screening and Identification of L-lysine-producing Probiotics

为了扩展高产L-赖氨酸菌种在食品、饲料中的应用与提高微生物发酵生产L-赖氨酸的安全性,从面包、麻花、馒头、发面饼、大列巴、黏豆包发酵谷物的生面团及米酒、白酒曲中分离培养出66株产L-赖氨酸益生菌菌株。将这些菌株进行培养、发酵,并利用高效液相色谱技术检测其发酵液中L-赖氨酸的含量,筛选出发酵液富含L-赖氨酸的菌种两株。最后利用16S rDNA分析及Blast分析、特异性引物PCR技术鉴定出这两株菌为肠膜明串球菌ATCC8293和德氏乳杆菌ATCC BAA-365。其发酵液中L-赖氨酸含量分别为52.33、46.09g/L,较其他菌种相对较高。

The present study aimed to expand the utilization of L-lysine-producing strains in food and animal feeds and raise the security of L-lysine production by microbial fermentation.In total,66 strains having the ability to produce L-lysine were isolated from commercially available doughs for the making of bread,fried dough twists,steamed bread,steamed cake and Russian style bread and kojis for the making of rice wine and distilled liquor.These strains were cultured,and the quantitation of L-lysine content in medium at the end of culture was carried out using HPLC.Two of the 66 isolated strains were found to produce higher amount of L-lysine and the contents of L-lysine in the resultant fermentation broths were 52.33 g/L and 46.09 g/L respectively.Using 16S rDNA sequence and Blast analyses and specific primer PCR technique,they were identified as Leuconostoc mesenteroides ATCC 8293 and Lactobacillus delbrueckii subsp.bulgaricus ATCC BAA-365.