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

Abstract

Bacteria of the genus Saccharopolyspora produce important polyketide antibiotics, including erythromycin A (Sac. erythraea) and spinosad (Sac. spinosa). We herein report the development of an industrial erythromycin-producing strain, Sac. erythraea HOE107, into a host for the heterologous expression of polyketide biosynthetic gene clusters (BGCs) from other Saccharopolyspora species and related actinomycetes. To facilitate the integration of natural product BGCs and auxiliary genes beneficial for the production of natural products, the erythromycin polyketide synthase (ery) genes were replaced with two bacterial attB genomic integration sites associated with bacteriophages ϕC31 and ϕBT1. We also established a highly efficient conjugation protocol for the introduction of large bacterial artificial chromosome (BAC) clones into Sac. erythraea strains. Based on this optimized protocol, an arrayed BAC library was effectively transferred into Sac. erythraea. The large spinosad gene cluster from Sac. spinosa and the actinorhodin gene cluster from Streptomyces coelicolor were successfully expressed in the ery deletion mutant. Deletion of the endogenous giant polyketide synthase genes pkeA1-pkeA4, the product of which is not known, and the flaviolin gene cluster (rpp) from the bacterium increased the heterologous production of spinosad and actinorhodin. Furthermore, integration of pJTU6728 carrying additional beneficial genes dramatically improved the yield of actinorhodin in the engineered Sac. erythraea strains. Our study demonstrated that the engineered Sac. erythraea strains SLQ185, LJ161, and LJ162 are good hosts for the expression of heterologous antibiotics and should aid in expression-based genome-mining approaches for the discovery of new and cryptic antibiotics from Streptomyces and rare actinomycetes.

Increasing the heterologous production of spinosad in Streptomyces albus J1074 by regulating biosynthesis of its polyketide skeleton

“…The original BGC of spinosad was heterologously expressed in Sa. erythraea, Streptomyces coelicolor, and S. lividans to obtain the spinosad titer of 1–3 mg/L [ 26 , 27 ]. Metabolic engineering has also be attempted in addition to the replacement of the chassis.…”

Volatile communication in Actinobacteria: a language for secondary metabolism regulation

“…In this work, fifteen Actinobacteria strains, among which there are 11 Streptomyces spp., have been co-cultivated in two different media and a large number of differences have been observed as a consequence of the effect of VCs from the companion organism: differences in sporulation, activation of silenced pathways, increased production of compounds, etc. Although not all of these Actinobacteria were isolated from the same niche, they are phylogenetically related and all of them present enormous metabolic potential [ 18 , 19 , 73 – 76 ]. However, the results have not shown any new unknown compounds.…”

Streptomyces BAC Cloning of a Large-Sized Biosynthetic Gene Cluster of NPP B1, a Potential SARS-CoV-2 RdRp Inhibitor

“…These results imply that there should be some unknown regulator(s) likely present only in Pseudonocardia species, which may play a critical regulatory role in NPP biosynthesis. Further research needs to be pursued to identify in more detail the relationship between global regulatory network and NPP-BAC clone expression in a rare actinomycetes like P. autotrophica [ 27 , 28 ]. In addition, more comparative and systematic studies should be conducted to find out why NPP B1 production was not observed when pNPPB1s or pNPPB1s+pNPPREG was expressed in heterologous hosts such as S. coelicolor and S. lividans (data not shown).…”