抗突变乳酸菌的筛选及其活性物质的分离纯化

Screening of antimutagenic lactic acid bacteria and purification of the antimutagenic substance

采用HPLC法及Ames法对实验室分离和保藏的36株乳酸菌进行筛选,其中乳杆菌L2发酵上清液对阳性物NQO及NPD具有较强的抗突变活性,并且36h的培养物活性最强。将L2发酵上清液进行DEAE-Spharose离子交换层析,收集样品中在A280处有吸收峰共16管,然后用截留分子量为3ku的超滤管进一步纯化脱盐,分别用HPLC法及Ames法对其抗突变活性进行鉴定。结果表明,其中3管具有较强活性,将它们进行PAGE,用考马斯亮蓝R250染色,各管在同一位置出现均一条带,并成功地染上了PAS试剂,因此可初步证明该物质为一种糖蛋白。

Lactobacillus L2 was screened by Ames test and HPLC method for its highest anfimutagenic activity against NQO and NPD among 36 test LAB strains. The supernatant from 36 h shake culture of L2 possessed the highest activity. The culture supernatant of L2 was fractionated and purified by DEAE-Sepharose ion-exchange chromatography, the fractions that have maximal absorb at 280nm were collected. Then, the fractions exhibiting antimutagenic acivity were concentrated and desalted by ultrafiltration with Amicon YM3 membrane, and three tubes of cluent were confirmed to have antimutagenic by Ames test and HPLC. Three active factions were stained with PAS as well as Coomassie brilliant blue R250 at the same position in the gel. It suggested that they were the same glycoprotein.