核黄素对双歧杆菌和蜡样芽孢杆菌增殖的影响

目的　探讨不同浓度核黄素对双歧杆菌、蜡样芽孢杆菌生长的影响。方法　应用常规细菌定量培养及革兰染色镜检技术 ,观察 1、0 5、0 2 5 g·L-1的核黄素对双歧杆菌和蜡样芽孢杆菌增殖生长的影响。结果　① 1g·L-1核黄素组 ,在 4 8h后双歧杆菌活菌数增加约 10～ 10 0倍 ;0 5和 0 2 5g·L-1核黄素组 ,在 72h内活菌数增加约 10～ 390倍 ,镜检示双歧杆菌链的长度亦增加。② 0 5g·L-1核黄素组 ,36h后蜡样芽孢杆菌活菌数增加 ;0 2 5 g·L-1核黄素组 ,在 72h内活菌数均增加 ,约 0 5～ 315倍 ,链长度增加 ,芽胞形成时间延迟。 (3) 4℃存放 ,悬液加核黄素 (0 5g·L-1)可提高双歧杆菌和蜡样芽孢杆菌 6mon内的存活率。结论　核黄素可促进双歧杆菌、蜡样芽孢杆菌的增殖 ,在一定范围内存在剂量依赖关系 ,并可提高悬液中双歧杆菌和蜡样芽孢杆菌的长期存活率

The effect of riboflavin on the growth of bifidobacterium adolescentis and bacillus cereus

AIM To investigate the potential effect of riboflavin on the growth of probiotic strains Bifidobacterium adolescentis ( B. adolescentis) and Bacillus cereus ( B. cereus) . METHODS By means of routine bacterial quantitative culture, Gram's staining, and light microscopy, changes in B. adolescentis and B. cereus counts were detected in the presence of riboflavin at different concentrations (1, 0 5, 0 25, 0 g·L -1 ). RESULTS ①The counts of B. adolescentis increased by 10 to 100 fold in 1g·L -1 riboflavin group after 48 h, and 10 to 390 fold in 0 5 g·L -1 and 0 25 g·L -1 riboflavin groups within 72 h as compared to that without riboflavin supplement. Meanwhile, the chain lengths of B. adolescentis were markedly longer in culture system with riboflavin than those without. ②Compared with 0 g·L -1 riboflavin group, the count of B. cereus increased significantly in 0 5 g·L -1 riboflavin group at 36 h, and in 0 25 g·L -1 riboflavin group within 72 h, while it decreased by 50 to 100 000 fold in 1 g·L -1 riboflavin group within 72 h. Likewise, the chain length of B. cereus was markedly longer in 0 5 g·L -1 and 0 25 g·L -1 riboflavin groups, together with the delayed spore formation of B. cereus. ③The 6 month survival rates of B. adolescentis and B. cereus counts in preparations (depositing at 4℃) with 0 5 g·L -1 riboflavin were much higher than those without riboflavin supplement. CONCLUSION Riboflavin in concentrations of 0 5 g·L -1 and 0 25 g·L -1 could markedly enhance the growth of B. adolescentis and B. cereus. 0 5 g·L -1 riboflavin might be beneficial to improve the survival rate of B. adolescentis as well as B. cereus when storing for a long term.