Heterologous expression of the biosynthetic gene clusters of coumermycin A₁, clorobiocin and caprazamycins in genetically modified Streptomyces coelicolor strains

Abstract

The biosynthetic gene clusters of the aminocoumarin antibiotics clorobiocin and coumermycin A(1) and of the liponucleoside antibiotic caprazamycin were stably integrated into the genomes of different host strains derived from Streptomyces coelicolor A3(2). For the heterologous expression of clorobiocin derivatives in a chemically defined medium, inclusion of 0.6% of the siloxylated ethylene oxide/propylene oxide copolymer Q2-5247 into the growth medium proved to result in a 4.8-fold increase of productivity. Presumably, this copolymer acts as an oxygen carrier. The additional inclusion of cobalt chloride (0.2-2 mg l(-1)) dramatically increased the percentage of the desired compound clorobiocin within the total produced clorobiocin derivatives. This is very likely due to a stimulation of a cobalamin-dependent methylation reaction catalyzed by the enzyme CloN6 of clorobiocin biosynthesis. All three investigated host strains (S. coelicolor M512, M1146 and M1154) gave similar production rates of total clorobiocin derivatives (on average, 158 mg l(-1) in the presence of 0.6% Q2-5247 and 0.2 mg l(-1) CoCl(2)). In contrast, heterologous production of caprazamycin derivatives was optimal in strain M1154 (amounts of 152 mg l(-1) on average).

Taxonomy, Physiology, and Natural Products of Actinobacteria

“…This is particularly important for heterologous expression of biosynthetic gene clusters that are being uncovered at a high rate in actinomycetes in the era of genome sequencing. In particular, the combination of synthetic biology approaches with expression in optimized heterologous Streptomyces production platforms is a promising development (403)(404)(405)(406)(407)(408).…”

Identification of a Napsamycin Biosynthesis Gene Cluster by Genome Mining

“…[48] We recently showed that S. coelicolor M1154 represents an excellent host strain for the heterologous production of liponucleoside antibiotics. [49] Therefore, the generated cosmid npsXT01 was introduced into S. coelicolor M1154 by triparental intergeneric conjugation, and three kanamycin resistance clones were selected. Extracts of cultures from the napsamycin producer strain Streptomyces sp.…”

Synthetic Biology Triggers New Era of Antibiotics Development

“…This minimized strain was successfully used for heterologous production of different classes of NPs with signi fi cant titers, e.g., aminoglycosides, nonribosomal peptides, polyketides and terpenes (Komatsu et al 2010 ) . Other related researches in S. coelicolor and E. coli further con fi rmed the superiority of genome minimized strains for various valuable compounds production (Flinspach et al 2010 ;Mizoguchi et al 2007 ) . Further improvements will be focused on the construction of biotechnologically synthetic platform cell with a minimized genome and ef fi cient regulatory structure, which can be easily customized for various pre-de fi ned tasks from producing therapeutics to decontaminating waste streams (Foley and Shuler 2010 ) .…”