Project description:Abstract: Transcript levels in production cultures of wildtype and classically improved strains of the actinomycete bacteria Saccharopolyspora erythraea and Streptomyces fradiae were monitored using microarrays of the sequenced actinomycete S. coelicolor. Sac. erythraea and S. fradiae synthesize the polyketide antibiotics erythromycin and tylosin, respectively, and the classically improved strains contain unknown overproduction mutations. The Sac. erythraea overproducer was found to express the entire 56-kb erythromycin gene cluster several days longer than the wildtype strain. In contrast, the S. fradiae wildtype and overproducer strains expressed the 85-kb tylosin biosynthetic gene cluster similarly, while they expressed several tens of other S. fradiae genes and S. coelicolor homologs differently, including the acyl-CoA dehydrogenase gene aco and the S. coelicolor isobutyryl-CoA mutase homolog icmA. These observations indicated that overproduction mechanisms in classically improved strains can affect both the timing and rate of antibiotic synthesis, and alter the regulation of antibiotic biosynthetic enzymes and enzymes involved in precursor metabolism. This SuperSeries is composed of the SubSeries listed below.
Project description:Abstract: Transcript levels in production cultures of wildtype and classically improved strains of the actinomycete bacteria Saccharopolyspora erythraea and Streptomyces fradiae were monitored using microarrays of the sequenced actinomycete S. coelicolor. Sac. erythraea and S. fradiae synthesize the polyketide antibiotics erythromycin and tylosin, respectively, and the classically improved strains contain unknown overproduction mutations. The Sac. erythraea overproducer was found to express the entire 56-kb erythromycin gene cluster several days longer than the wildtype strain. In contrast, the S. fradiae wildtype and overproducer strains expressed the 85-kb tylosin biosynthetic gene cluster similarly, while they expressed several tens of other S. fradiae genes and S. coelicolor homologs differently, including the acyl-CoA dehydrogenase gene aco and the S. coelicolor isobutyryl-CoA mutase homolog icmA. These observations indicated that overproduction mechanisms in classically improved strains can affect both the timing and rate of antibiotic synthesis, and alter the regulation of antibiotic biosynthetic enzymes and enzymes involved in precursor metabolism. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
Project description:>1000 raw files from actinomycete extracts. ISP2, DNPM, and FPY12 media were used to grow every strain (approximately 100 strains) and triplicates for every treatment. This dataset was used to build and test UmetaFlow, an untargeted metabolomics computational workflow for high-throughput processing and analysis. Not all data were deposited because of confidentiality. Preprint connected to data DOI: 10.26434/chemrxiv-2022-z0t4g
Project description:Actinomycete genomes contain a plethora of orphan gene clusters encoding unknown secondary metabolites, and representing a huge unexploited pool of chemical diversity. The explosive increase in genome sequencing and the massive advance of bioinformatic tools have revolutionized the rationale for natural product discovery from actinomycetes. In this context, we applied a genome mining approach to discover a group of unique catecholate-hydroxamate siderophores termed as qinichelins from Streptomyces sp. MBT76. Quantitative proteomics statistically correlated a gene cluster of interest (qch) to its unknown chemotype (qinichelin), after which structural elucidation of isolated qinichelin was assisted by bioinformatics analysis and verified by MS2 and NMR experiments. Strikingly, intertwined functional crosstalk among four separately located gene clusters was implicated in the biosynthesis of qinichelins.
