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 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.
2013-08-16 | GSE23660 | GEO
Project description:Isolation of Endogenous Probiotic
Project description:Propionibacterium freudenreichii, a dairy starter, reaches a population close to 10^9 propionibacteria per gram of Swiss-type cheese at the time of consumption. Also consumed as a probiotic, it revealed strain-dependent anti-inflammatory properties mediated by proteins inducing IL-10 in leukocytes. Here, strains with varied anti-inflammatory potentials were compared in terms of transcriptome profiles.
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. 42 samples were hybridized to the microarray chip, which contains probe sequences from L. helveticus CNRZ32. CNRZ32 was also hybridized and used as the reference sample. Data from the microarray was statistically analyzed using the R software. Samples were compared to the reference (CNRZ32) to investigate genome diversity amoung L. helveticus strains,
Project description:Bacillus licheniformis (B. licheniformis) is a microorganism with a wide range of probiotic properties and applications. Isolation and identification of novel strains is a major aspect of microbial research. Besides, the role of different carbon sources affects B. licheniformis in regulating micro-environment and the mechanisms need to be further investigated. In this study, we first isolated and identified a new strain of B. licheniformis from bovine rumen fluid. Microcrystalline cellulose (MC) and cellobiose (CB) as the certain carbon sources to treat strain. Further, a combination of transcriptome and proteome analyses was used to different carbon sources effects. The results showed that B. licheniformis ABC transporter proteins, antibiotic synthesis, flagellar assembly, cellulase-related pathways and proteins were significantly up-regulated in the MC treatment compared to the CB treatment, and lactate metabolism was inhibited. In addition, MC was used as a certain carbon source to improve bacterial inhibition of B. licheniformis, its own disease resistance and to regulate the rumen micro-environment. In conclusion, our research provides a potential new probiotic for feed research and a theoretical basis for investigating the mechanisms by which bacteria respond to different carbon sources.