Project description:Transcriptomic analysis was performed in Deinococcus geothermalis wild-type and three mutants including dgeo_0257, dgeo_0281, and double knockout (DK) mutants. dgeo_0281 is a major Dps-coding gene and dgeo_0257 is a novel Dps candidate. Thus, to detecte physiological functions of both Dps-encoded genes, each gene-disrupted mutant and DK mutant was constructed and performed RNA-Seq analysis. This result support better understanding for Dps roles in radiation resistant bacterium through up-regulated and down-regulated genes profile.
Project description:Here, we compared gene expression level by RNA-Seq analysis among a wild-type (WT) Deinococcus geothermalis strain, a dgeo_2840 of LysR family member gene (Δdgeo_2840), a putative Dps dgeo_0257 (Δdgeo_0257), and a cystine importer dgeo_1986-1987 gene disrupted strain (Δdgeo_1986-1987). From this transcriptomic data, we detected dgeo_2840, dgeo_0257, and dgeo_1986-1987 controlling genes which were somehow up-regulated and/or down-regulated. In particular, Deinococcus geothermalis has a total of 73 insertion sequences (ISs) in genomes, and some of them are actively transposed to other loci with replicative mode by the oxidative stress of hydrogen peroxide treatment.
Project description:Deinococcus metallilatus MA1002 was exposed to ultraviolet radiation to generate mutants with enhanced biofilm production. Two strains (nos 5 and 6) were then selected based on their high biofilm formation, as well as their possession of higher concentrations of extracellular matrix components (eDNA, protein and saccharides) than the wild-type (WT). Genomic sequencing revealed the presence of large genome deletions in a secondary chromosome in the mutants. Expression analyses of the WT and mutant strains indicated the upregulation of genes associated with exopolysaccharide synthesis and stress response. The mutant strains showed high mortality in glucose-supplemented (TYG) medium; however, cell death and biofilm formation were not increased in mutant cells grown under acetate- or glyoxylate-added media, suggesting that metabolic toxicity during glucose metabolism induced a high rate of cell death but improved biofilm formation in mutant strains. In damaged cells, eDNAs contributed to the enhanced biofilm formation of D. metallilatus.