A comparative study at bioprocess and metabolite levels of superhost strain Streptomyces coelicolor M1152 and its derivative M1581 heterologously expressing chloramphenicol biosynthetic gene cluster

Microbial superhost strains should provide an ideal platform for the efficient homologous or heterologous phenotypic expression of biosynthetic gene clusters (BGCs) of new and novel bioactive molecules. Our aim in the current study was to perform a comparative study at the bioprocess and metabolite levels of the previously designed superhost strain Streptomyces coelicolor M1152 and its derivative strain S. coelicolor M1581 heterologously expressing chloramphenicol BGC. Parent strain M1152 was characterized by a higher specific growth rate, specific CO2 evolution rate, and a higher specific l-glutamate consumption rate as compared with M1581. Intracellular primary central metabolites (nucleoside/sugar phosphates, amino acids, organic acids, and CoAs) were quantified using four targeted LC-MS/MS-based methods. The metabolite pathways in the nonantibiotic producing S. coelicolor host strain were flooded with carbon from both carbon sources, whereas in antibiotic-producing strain, the carbon of l-glutamate seems to be draining out through excreting synthesized antibiotic. The C-13-isotope-labeling experiments revealed the bidirectionality in the glycolytic pathway and reversibility in the non-oxidative part of PPP even with continuous uptake of d-glucose. The change in the primary metabolites due to the insertion of BGC disclosed a clear linkage between the primary and secondary metabolites.

Automated summary

Microbial superhost strains serve as an ideal platform for the efficient expression of biosynthetic gene clusters (BGCs) of bioactive molecules. In this study, a comparative analysis was carried out between the superhost strain Streptomyces coelicolor M1152 and its derivative strain S. coelicolor M1581 expressing the chloramphenicol BGC. The study revealed differences in growth rates, metabolism, and metabolite pathways between the two strains.