Generation and study of the strains of streptomycetes-heterologous hosts for the production of moenomycin

Abstract

Moenomycins (Mm) are family of phosphoglycolipid natural products that is considered a blueprint to develop new class of antibiotics. The natural Mm producer, Streptomyces ghanaensis (ATCC14672), produces very low amounts of moenomycin, fueling the investigations on genetic approaches to improve its titers. Heterologous expression of moenomycin biosynthesis gene cluster (moe) would be one of the ways to reach this goal. Here we report the generation of a number of novel heterologous streptomycete hosts producing nosokomycin A2 (one of the members of Mm family), and determine their potential for the antibiotic production. The rpoB point mutation in the model strain of Streptomyces genetics, S. coelicolor (strain M1152) significantly improved nosokomycin A2 production compared to parental strains (M145 and M512), while double rpoBrpsL mutation in the same species (strain M1154) decreased it. Our results point to the previously unanticipated epistatic interactions between mutations that individually are known to be highly beneficial for antibiotic production. We also showed here for the first time that facultative chemolitotrophic streptomycete S. thermospinosisporus and chloramphenicol producer S. venezuelae can be used as the hosts for moe genes.

Properties of Streptomyces albus J1074 mutant deficient in tRNALeu UAA gene bldA

“…Moenomycin production was analyzed in S. albus strains carrying cosmid moeno38-6. The latter leads to accumulation of two moenomycins in S. albus -nosokomycin A2 and its precursor lacking terminal galacturonic residue Lopatniuk et al 2014). Strains were grown in SG1.…”

“…Next we compared the ability of SAM2 and OK3 to heterologously produce antibiotics whose biosynthesis depends on TTA codon-containing genes. These were moenomycin and aranciamycin biosynthesis gene clusters, carried on cosmids moeno38-6 (Lopatniuk et al 2014) and pOJ436ara (Luzhetskyy et al 2007), respectively. As can be judged from bioactivity and TLC-based assays, moeno38-6 + and pOJ436ara + transconjugants of the parental strain abundantly produced respective antibiotics, while OK3 strain did not ( Fig.…”

“…Fast, highly dispersed growth and genetic amenability make J1074 a strain of first choice for expression of heterologous gene clusters from actinobacteria (Baltz 2010). Previous studies (Lopatniuk et al 2014;Iqbal et al 2016) portray J1074 as an optimal starting point to develop efficient platform for heterologous expression (metagenomic) purposes. It is expected that such a platform would greatly increase our ability to discover bioactive natural products encrypted in environmental DNA and silent gene clusters of actinobacteria.…”

Enzyme-constrained models and omics analysis of Streptomyces coelicolor reveal metabolic changes that enhance heterologous production

“…It is intriguing that the M1146 mutant strain in contrast has an increased growth rate compared to M145 (Coze et al, 2013a), as the only difference between these two strains is the rpoB single point mutation, which has been shown to enhance antibiotic production without growth impairment in S. lividans (Hu et al, 2002). However, epistatic interactions involving rpoB has caused unexpected results in S. coelicolor previously (Lopatniuk et al, 2014), and different cultivation conditions when independently comparing strains may contribute to obtaining contradictory results.…”

Genetic Engineering of Streptomyces ghanaensis ATCC14672 for Improved Production of Moenomycins

“…This forces the studies aimed to construct strains with higher Mm production titers and better growth characteristics. To achieve this, several heterologous hosts were successfully utilized to express the Mm biosynthetic gene cluster (moe cluster); however, the level of Mm biosynthesis was still lower than in the wild type [16,17]. Several studies have been undertaken to explore the regulation of Mm biosynthesis.…”