English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Natural polyketides play important roles in clinical treatment, agriculture, and animal husbandry. Compared to natural hosts, heterologous chassis (especially Actinomycetes) have many advantages in production of polyketide compounds. As a widely studied model Actinomycete,  Saccharopolyspora erythraea  is an excellent host to produce valuable heterologous polyketide compounds. However, many host factors affect the expression efficiency of heterologous genes, and it is necessary to modify the host to adapt heterologous production. In this study, the CRISPR-Cas9 system was used to knock out the erythromycin biosynthesis gene cluster of Ab (erythromycin high producing stain). A fragment of 49491 bp in genome (from SACE_0715 to SACE_0733) was deleted, generating the recombinant strain AbΔ ery  in which erythromycin synthesis was blocked and synthetic substrates methylmalonyl-CoA and propionyl-CoA accumulated enormously. Based on AbΔ ery  as heterologous host, three genes, AsCHS, RgTAL, and Sc4CL, driven by strong promoters Pj23119, PermE, and PkasO, respectively, were introduced to produce novel polyketide by  L -tyrosine and methylmalonyl-CoA. The product ( E )-4-hydroxy-6-(4-hydroxystyryl)-3,5-dimethyl-2H-pyrone was identified in fermentation by LC-MS. High performance liquid chromatography analysis showed that knocking out  ery  BGC resulted in an increase of methylmalonyl-CoA by 142% and propionyl-CoA by 57.9% in AbΔ ery  compared to WT, and the yield of heterologous product in AbΔ ery :AsCHS-RgTAL-Sc4CL was higher than WT:AsCHS-RgTAL-Sc4CL. In summary, this study showed that AbΔ ery  could potentially serve as a precious heterologous host to boost the synthesis of other valuable polyketone compounds using methylmalonyl-CoA and propionyl-CoA in the future.

Reconstruction of Secondary Metabolic Pathway to Synthesize Novel Metabolite in Saccharopolyspora erythraea