Genetic approaches to generate hyper-producing strains of goadsporin: the relationships between productivity and gene duplication in secondary metabolite biosynthesis

Abstract

Improving the productivity of secondary metabolites is highly beneficial for the utilization of natural products. Here, we found that gene duplication of the goadsporin biosynthetic gene locus resulted in hyper-production. Goadsporin is a linear azole containing peptide that is biosynthesized via a ribosome-mediated pathway in Streptomyces sp. TP-A0584. Recombinant strains containing duplicated or triplicated goadsporin biosynthetic gene clusters produced 1.46- and 2.25-fold more goadsporin than the wild-type strain. In a surrogate host, Streptomyces lividans, chromosomal integration of one or two copies of the gene cluster led to 342.7 and 593.5 mg/L of goadsporin production. Expression of godI, a self-resistance gene, and of godR, a pathway-specific transcriptional regulator, under a constitutive promoter gave 0.79- and 2.12-fold higher goadsporin production than the wild-type strain. Our experiments indicated that a proportional relationship exists between goadsporin production per culture volume and the copy number of the biosynthetic gene cluster.

Graphical Abstract

Proportional relationship exists between Streptomyces antibiotic production and the copy number of the biosynthetic gene cluster.

Key words:

• antibiotic biosynthesis
• gene dosage
• heterologous expression
• Streptomyces
• secondary metabolism

Funding

This work was supported in part by grants-in-aid from the New Energy and Industrial Technology Development Organization (NEDO) of Japan (to H. O.), Institution of Fermentation, Osaka (to S. A., T. O., and H. O.), and a JSPS KAKENHI (grant number 25108707 to H. O.).