Project description:The present study reports comparative surfacomics (study of cell-surface exposed proteins) of the probiotic Lactobacillus rhamnosus strain GG and the dairy strain Lc705.
Project description:Lactobacillus casei is remarkably adaptive to diverse habitats. To understand the evolution and adaptation of Lb. casei strains isolated from different environments, the gene content of 22 Lb. casei strains isolated from various habitats (cheeses, n=8; plant materials, n=8; and human sources, n=6) were examined by comparative genome hybridization with an Lb. casei ATCC 334-based microarray.
Project description:Lactobacillus helveticus is a rod-shaped lactic acid bacterium that is widely used in the manufacture of fermented dairy foods and for production of bioactive peptides from milk proteins. Although L. helveticus is commonly associated with milk environments, phylogenetic studies show it is closely related to an intestinal species, Lactobacillus acidophilus, which has been shown to impart probiotic health benefits to humans. This relationship has fueled a prevailing hypothesis that L. helveticus is a highly specialized derivative of L. acidophilus which has adapted to acidified whey. However, L. helveticus has also been sporadically recovered from non-dairy environments, which argues the species may not be as highly specialized as is widely believed. This study employed genome sequence analysis and comparative genome hybridizations to investigate genomic diversity among L. helveticus strains collected from cheese, whey, and whiskey malt, as well as commercial cultures used in manufacture of cheese or bioactive dairy foods. Results revealed considerable variability in gene content between some L. helveticus strains, and indicated the species should not be viewed as a strict dairy-niche specialist. In addition, comparative genomic analyses provided new insight on several industrially and ecologically important attributes of L. helveticus that may facilitate commercial strain selection.
Project description:Bacterial membrane vesicles have been implicated in a broad range of functions in microbial communities from pathogenesis to gene transfer. Though first thought to be a phenomenon associated with Gram-negative bacteria, vesicle production in Staphylococcus aureus, Lactobacillus plantarum, and other Gram-positives has recently been described. Here we characterize MVs from three different Lactobacillus species (L. acidophilus, L. casei, and L. reuteri), determining that the size and protein composition of Lactobacillus-derived MVs have both similarities and differences with those produced by Gram-negative bacteria. Using proteomics, we identified more than 80 protein components from Lactobacillus-derived MVs, including some that were enriched in the vesicles themselves. For each species, vesicular proteins were categorized based on biological pathway and examined for subcellular localization signals in an effort to identify possible sorting mechanisms for MV proteins. Additionally, differences between MVs of other Lactobacillus species and Gram positive bacteria were highlighted. Information in this study will assist in elucidation of the formation and functions of MVs, as well as the development of therapeutic tools for vaccines, diagnosis, and therapeutic delivery.
Project description:Lactobacillus casei is remarkably adaptive to diverse habitats. To understand the evolution and adaptation of Lb. casei strains isolated from different environments, the gene content of 22 Lb. casei strains isolated from various habitats (cheeses, n=8; plant materials, n=8; and human sources, n=6) were examined by comparative genome hybridization with an Lb. casei ATCC 334-based microarray. Comparative genome hybridization was performed against an Affymetrix custom microarray designed to include 2,661 (97%) chromosomal and 17 (85%) plasmid CDSs predicted to occur in Lb. casei ATCC 334, as well as all predicted CDSs in the draft Lb. helveticus CNRZ 32 genome. CDSs that were not included in the microarray design were all transposase-encoding genes.
Project description:We transplanted Klebsiella and Lactobacillus to germ free C57/B6J mice. All of the recipients mice were male. Here we report the intestine mRNA profiles of recipients mice with Klebsiella and Lactobacillus.