Reverse engineering of industrial pharmaceutical-producing actinomycete strains using DNA microarrays

• Published in: Metabolic engineering 2004-07, Vol.6 (3), p.186-196
• Main Authors: Lum, Amy M, Huang, Jianqiang, Hutchinson, C.Richard, Kao, Camilla M
• Format: Article
• Language: English
• Subjects: Actinobacteria - genetics; Actinobacteria - metabolism; Acyl-CoA Dehydrogenase - genetics; Acyl-CoA Dehydrogenase - metabolism; Anti-Bacterial Agents - biosynthesis; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Drug Industry - methods; Erythromycin - biosynthesis; Gene Expression Profiling - methods; Gene Expression Regulation, Bacterial - physiology; Genetic Enhancement - methods; Genome, Bacterial; Isomerases - genetics; Isomerases - metabolism; Oligonucleotide Array Sequence Analysis - methods; Pharmaceutical Preparations - metabolism; Saccharopolyspora - genetics; Saccharopolyspora - metabolism; Species Specificity; Streptomyces - genetics; Streptomyces - metabolism; Tylosin - biosynthesis
• ISSN: 1096-7176; 1096-7184
• DOI: 10.1016/j.ymben.2003.12.001

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.