Project description:Bacterial genomic plasticity and instability carry multiple functional genetic information in Streptomyces secondary metabolism. Our previously publication has reported an effective industrial Streptomyces strain, with a unique phenotype of the high clavulanic acid yield. The complete genome of strain F163-1 harboring a 136.9-kb giant region of plasticity (RGP) was sequenced. The chromosome and plasmid are densely packed by an exceptionally huge variety of potential secondary metabolic gene clusters, excluding production of putative antibiotics. Intriguingly, architecture and size differences of plasmid pSCL4 between F613-1 and ATCC 27064 suggest the pSCL4 plasmid evolving from pSCL4-like and pSCL2-like extrachromosomal replicons, in addition to the previously proposed ATCC 27064 mega-plasmid formation hypothesis through recombination between the smaller F613-1 pSCL4 plasmid arm regions and the linear chromosome. Comparative genomics systemically investigate secondary metabolism capacitates in this study indicates that frequent exchange of genetic materials between Streptomyces replicons may shape remarkable diversities of secondary metabolite repertoires. Consequently, the F613-1 strain seems to have evolved its specific genomic architectures and genetic patterns to meet the requirement in subsequent industrial processes.
Project description:The whiH gene is required for the differentiation of aerial hyphae into spores in Streptomyces species. It is a predicted member of the GntR family of transcription factors and has been shown to bind specifically to a sequence in its own promoter. This ChIP-Seq experiment was carried out to determine all the binding sites whiH binds to in the genome of Streptomyces venezuelae. A whiH deletion strain was made and a FLAG tagged whiH protein was expressed in it from a genome-integrated plasmid. Then anti-FLAG antibodies were used for chromatin immunoprecipitation followed by high throughput sequencing. The wild type Streptomyces venezuelae strain (ATCC 10712) was used as a negative control. For both the FLAG-WhiH strain and the WT strain, non-immunoprecipitated (total) DNA was also sequenced to arrive at a background enrichment which could be subtracted from the enrichment in the immunoprecipated sample.
Project description:The terminal compartments of Streptomyces are less prone to transcription than the rest of the chromosome. Indeed, the expression of the highly variable regions enriched in those compartments is generally conditional and often requires an empirical approach to characterize the inducing conditions. For instance, in the context of identifying adequate antibiotic production conditions, an OSMAC (“One Strain Many Compounds”) approach is frequently implemented, based on strain cultivation in different environmental conditions (composition of the medium, growth time, temperature, co-cultures, etc.). Likewise, to find the expression conditions of a complete prophage of Streptomyces ambofaciens ATCC 23877 (named 'Samy' phage/prophage), we conducted a similar approach by analyzing the transcriptomes in five solid media (HT, SAF, ONA, MMM, MMM+NAG). The terminal compartments of Streptomyces are less prone to transcription than the rest of the chromosome. Indeed, the expression of the highly variable regions enriched in those compartments is generally conditional and often requires an empirical approach to characterize the inducing conditions. For instance, in the context of identifying adequate antibiotic production conditions, an OSMAC (“One Strain Many Compounds”) approach is frequently implemented, based on strain cultivation in different environmental conditions (composition of the medium, growth time, temperature, co-cultures, etc.). Likewise, to find the expression conditions of a complete prophage of Streptomyces ambofaciens ATCC 23877 (named 'Samy' phage/prophage), we conducted a similar approach by analyzing the transcriptomes in five solid media (HT, SAF, ONA, MMM, MMM+NAG).
Project description:Bacteria belonging to phylum Gemmatimonadetes are found in a wide variety of environments and are particularly abundant in soils. To date, only two Gemmatimonadetes strains have been characterized. Here we report the complete genome sequence and methylation pattern of Gemmatirosa kalamazoonensis KBS708 (ATCC BAA-2150; NCCB 100411), the first characterized Gemmatimondetes strain isolated from soil.
Project description:Streptomyces bingchenggensis is a soil bacterium that produces a family of macrolide antibiotics, milbemycins, which is commercially important in crop protection, human and veterinary medicine. After the complete genome sequence, and annotation, for further development of our gene expression approach to biosynthesis, we have employed whole genome microarray expression profiling as a discovery platform to obtain improved specificity and sensitivity of gene expression analysis, allowing a global and at the same time detailed picture of how gene clusters for secondary metabolism are modulated. In the result, we confirmed the expression mil and nan gene cluster, furthermore, pks3, pks5 and nrps7, nrps8 also showed significant gene expression, but no obvious products detected. In Streptomyces bingchenggensis, there are also corresponding genes belonging to Defense mechanisms, which is much more than other Streptomyces, for the resistance of own metabolites and dealing with complex environmental factors.