The compact genome in the clavulanic acid producing Streptomyces strain unravels a variety of horizontal transfer reservoirs
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ABSTRACT: 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:Clavulanic acid is a clinically-important secondary metabolite used in treatment of infectious diseases. We aimed to decipher complex regulatory mechanisms acting in clavulanic acid biosynthesis through the analysis of transcriptome- and proteome-wide alterations in an industrial clavulanic acid overproducer Streptomyces clavuligerus, namely DEPA and its wild-type counterpart NRRL3585.
Project description:To increase production of the important pharmaceutical compounds, both mutagenesis approaches and rational engineering have been extensively applied. Mutagenesis approaches are most popular in industry, but their effects have not yet been studied very well. Here, we used microarrays to compare the transcriptomes of the S. clavuligerus wild type (ATCC 27064) strain and the DS48802 clavulanic acid high-producer strain, which has been obtained by classical strain improvement (mutagenesis). Streptomyces clavuligerus strains were grown in shake flasks. RNA was extracted after 70h and hybridized to microarrays.
Project description:The aim of this work was to unveil the molecular mechanisms by which Streptomyces respond to a ROS intracellular imbalance and the effect of such response on the biosynthesis of secondary metabolites. The study was focused on the industrial actinomycete S. natalensis ATCC 27448 producer of the polyene pimaricin - an antifungal agent widely used in the food industry and promising for antiviral activity and stimulation of immune response.
Project description:The aim of this work was to unveil the molecular mechanisms by which Streptomyces respond to a ROS intracellular imbalance and the effect of such response on the biosynthesis of secondary metabolites. The study was focused on the industrial actinomycete S. natalensis ATCC 27448 producer of the polyene pimaricin - an antifungal agent widely used in the food industry and promising for antiviral activity and stimulation of immune response. Two-color microarray with common reference. The transcriptomes of S. natalensis ATCC 27448 (wild-type), S. natalensis CAM.02 (DsodF) and S. natalensis CAM.04 (DahpCD) were compared. Two time points were included: late exponential (T1) and early stationay (T2) phase. Biological triplicates were performed for each strain/time point. Genomic DNA of S. natalensis ATCC 27448 was used as common reference.
Project description:To investigate the function of organic nitrogen on clavulanic acid biosynthesis in Streptomyces clavuligerus, we established F613-1 strain cells cultured in MH fermentation medium and ML fermentation medium. We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different medium at three time points.
Project description:To increase production of the important pharmaceutical compounds, both mutagenesis approaches and rational engineering have been extensively applied. Mutagenesis approaches are most popular in industry, but their effects have not yet been studied very well. Here, we used microarrays to compare the transcriptomes of the S. clavuligerus wild type (ATCC 27064) strain and the DS48802 clavulanic acid high-producer strain, which has been obtained by classical strain improvement (mutagenesis).
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:This project contributes to the proteomic comparison of Bacillus cereus ATCC 14579 wild-type strain and the derivative strain cured of the linear plasmid, B. cereus ATCC 14579 -pBClin15, grown in aerobiosis condition and harvested at three growth stages.
Project description:This project contributes to the proteomic comparison of Bacillus cereus ATCC 14579 wild-type strain and the derivative strain cured of the linear plasmid, B. cereus ATCC 14579 -pBClin15, grown in aerobiosis condition and harvested at three growth stages.
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).