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 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:The objective was to analyze the differential expression between the wild strain and the Streptomyces clavuligerus ΔclaR::aac mutant Six experimental conditions were assayed, two strains (Streptomyces clavuligerus ATCC 27064, S. clavuligerus ΔclaR::aac) in three culture times (22.5h, 46.5h and 60 h). Two biological replicates for each condition.
Project description:In this study the transcriptomes of Acinetobacter baumannii strains ATCC 17978 and 17978hm were compared. Strain 17978hm is a hns knockout derivative of strain ATCC 17978. Strain 17978hm displays a hyper-motile phenotype on semi-solid Mueller-Hinton (MH) media (0.25% agar). ATCC 17978 and 17978hm from an 37C overnight culture were transferred to the centre of the semi-solid MH plate and incubated at 37C for 8 hours. Only 17978hm cells displayed a motile phenotype and covered the complete surface of the plate. These motile 17978hm cells and the non-motile wild-type ATCC 17978 cells were harvested and RNA was isolated. The comparative transcriptome analysis was performed using the FairPlay labeling kit and a custom made Agilent MicroArray with probes designed to coding regions of the ATCC 17978 genome. The data was analyzed using Agilent GeneSpring GX9 and the significance analysis of microarray MS Excel add-on.
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.