Project description:Bacteroidaceae are common gut microbiota members in all warm-blooded animals. However, if Bacteroidaceae are to be used as probiotics, the species selected for different hosts should reflect the natural distribution. In this study, we therefore evaluated host adaptation of bacterial species belonging to the family Bacteroidaceae. B. dorei, B. uniformis, B. xylanisolvens, B. ovatus, B. clarus, B. thetaiotaomicron and B. vulgatus represented human-adapted species while B. gallinaceum, B. caecigallinarum, B. mediterraneensis, B. caecicola, M. massiliensis, B. plebeius and B. coprocola were commonly detected in chicken but not human gut microbiota. There were 29 genes which were present in all human-adapted Bacteroides but absent from the genomes of all chicken isolates and these included genes required for the pentose cycle, and glutamate or histidine metabolism. These genes were expressed during an in vitro competitive assay, in which human-adapted Bacteroides species overgrew the chicken adapted isolates. Not a single gene specific for the chicken-adapted species was found. Instead, chicken adapted species exhibited signs of frequent horizontal gene transfer, of KUP, linA and sugE genes in particular. The differences in host adaptation should be considered when the new generation of probiotics for humans or chickens is designed.
Project description:Investigation of whole genome gene expression level changes in Lactococcus lactis KCTC 3769T,L. raffinolactis DSM 20443T, L. plantarum DSM 20686T, L. fujiensis JSM 16395T, L. garvieae KCTC 3772T, L. piscium DSM 6634T and L. chungangensis CAU 28T . This proves that transcriptional profiling can facilitate in elucidating the genetic distance between closely related strains.
