Heterologous Expression of Spinosyn Biosynthetic Gene Cluster in <b><i>Streptomyces</i></b> Species Is Dependent on the Expression of Rhamnose Biosynthesis Genes

Abstract

Spinosyns are a group of macrolide insecticides produced by Saccharopolyspora spinosa. Although S. spinosa can be used for industrial-scale production of spinosyns, this might suffer from several limitations, mainly related to its long growth cycle, low fermentation biomass, and inefficient utilization of starch. It is crucial to generate a robust strain for further spinosyn production and the development of spinosyn derivatives. A BAC vector, containing the whole biosynthetic gene cluster for spinosyn (74 kb) and the elements required for conjugal transfer and site-specific integration, was introduced into different Streptomyces hosts in order to obtain heterologous spinosyn-producing strains. The exconjugants of different Streptomyces strains did not show spinosyn production unless the rhamnose biosynthesis genes from S. spinosa genomic DNA were present and expressed under the control of a strong constitutive ermE*p promoter. Using this heterologous expression system resulted in yields of 1 μg/mL and 1.5 μg/mL spinosyns in Streptomyces coelicolor and Streptomyces lividans, respectively. This report demonstrates spinosyn production in 2 Streptomyces strains and stresses the essential role of rhamnose in this process. This work also provides a potential alternative route for producing spinosyn analogs by means of genetic manipulation in the heterologous hosts.

Engineering the Erythromycin-Producing Strain Saccharopolyspora erythraea HOE107 for the Heterologous Production of Polyketide Antibiotics

“…erythraea ATCC 40137 (Huang et al, 2016); through substantial genetic engineering and mutagenesis, this heterologous expression system allowed spinosad production to reached a titer of 800 mg/L in the resulting Sac. erythraea strain, which is hundreds of times higher than those in Streptomyces hosts, including S. albus, S. coelicolor, and S. lividans (Huang et al, 2016;Tan et al, 2017;Zhao et al, 2017). These studies confirmed the suitability of Saccharopolyspora spp.…”

Effect of the TetR family transcriptional regulator Sp1418 on the global metabolic network of Saccharopolyspora pogona

“…The structure and biosynthesis of spinosyn analogues have been clearly described [4,33], and studies on the transformation of its gene clusters and the improvement of heterologous expression have been studied [7,34,35]; however, the metabolic situation in vivo is complex, and any slight metabolic disturbance will lead to complex changes, which may produce unintended consequences [11]. Therefore, the analysis of the genome characteristics of S. pogona and related regulatory proteins may help to understand their gene expression preferences.…”

“…Chaoyi Song et al constructed a spinosyn artificial gene cluster grouped into 7 operons, each with a strong constitutive promoter, and compared with the original gene cluster, the artificial gene cluster resulted in a 328-fold enhanced spinosyn production in Streptomyces albus J1074 [6]. Analogously, Tan et al overexpressed three rate-limiting steps of the heterologous production of spinosyn, and the production of spinosyn was increased gradually and finally reached 1.46 mg/L, which was approximately 1000-fold higher than the level of spinosyn produced by the wild-type strain S. albus J1074 [7]. However, probably due to the complex genetic background and the native advantages of natural hosts, the heterologous production of spinosyn analogues usually falls short of expectations.…”

Strategies for Enhancing the Yield of the Potent Insecticide Spinosad in Actinomycetes

“…The spinosyn biosynthetic pathway has been introduced into S. lividans TK24 and S. coelicolor M145 and M1154 . However, heterologous biosynthesis of target compounds is just the starting point as the production of NPs is very low.…”