Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
Appl Environ Microbiol. 2013 Mar;79(6):1923-33. doi: 10.1128/AEM.03467-12. Epub 2013 Jan 11.
Four Lactobacillus strains were isolated from marketed probiotic products, including L. rhamnosus strains from Vifit (Friesland Campina) and Idoform (Ferrosan) and L. casei strains from Actimel (Danone) and Yakult (Yakult Honsa Co.). Their genomes and phenotypes were characterized and compared in detail with L. casei strain BL23 and L. rhamnosus strain GG. Phenotypic analysis of the new isolates indicated differences in carbohydrate utilization between L. casei and L. rhamnosus strains, which could be linked to their genotypes. The two isolated L. rhamnosus strains had genomes that were virtually identical to that of L. rhamnosus GG, testifying to their genomic stability and integrity in food products. The L. casei strains showed much greater genomic heterogeneity. Remarkably, all strains contained an intact spaCBA pilus gene cluster. However, only the L. rhamnosus strains produced mucus-binding SpaCBA pili under the conditions tested. Transcription initiation mapping demonstrated that the insertion of an iso-IS30 element upstream of the pilus gene cluster in L. rhamnosus strains but absent in L. casei strains had constituted a functional promoter driving pilus gene expression. All L. rhamnosus strains triggered an NF-κB response via Toll-like receptor 2 (TLR2) in a reporter cell line, whereas the L. casei strains did not or did so to a much lesser extent. This study demonstrates that the two L. rhamnosus strains isolated from probiotic products are virtually identical to L. rhamnosus GG and further highlights the differences between these and L. casei strains widely marketed as probiotics, in terms of genome content, mucus-binding and metabolic capacities, and host signaling capabilities.
从市售益生菌产品中分离出 4 株乳杆菌，包括来自 Vifit（Friesland Campina）和 Idoform（Ferrosan）的 L. rhamnosus 株和来自 Actimel（Danone）和 Yakult（Yakult Honsa Co.）的 L. casei 株。详细比较了它们的基因组和表型，并与 L. casei 株 BL23 和 L. rhamnosus 株 GG 进行了比较。新分离株的表型分析表明，L. casei 和 L. rhamnosus 株之间的碳水化合物利用存在差异，这可能与其基因型有关。这两个分离的 L. rhamnosus 株的基因组与 L. rhamnosus GG 的基因组几乎完全相同，证明了它们在食品中的基因组稳定性和完整性。L. casei 株显示出更大的基因组异质性。值得注意的是，所有菌株都含有完整的 spaCBA 菌毛基因簇。然而，只有 L. rhamnosus 株在测试条件下产生粘蛋白结合的 SpaCBA 菌毛。转录起始图谱表明，在 L. rhamnosus 株中，插入一个 iso-IS30 元件在菌毛基因簇的上游，而在 L. casei 株中不存在，这构成了一个功能性启动子，驱动菌毛基因的表达。所有 L. rhamnosus 株在报告细胞系中通过 Toll 样受体 2（TLR2）触发 NF-κB 反应，而 L. casei 株则没有或反应程度较小。这项研究表明，从益生菌产品中分离出的 2 株 L. rhamnosus 株与 L. rhamnosus GG 几乎相同，进一步突出了它们与作为益生菌广泛销售的 L. casei 株在基因组内容、粘蛋白结合和代谢能力以及宿主信号转导能力方面的差异。
