Identification and Heterologous Expression of the Kendomycin B Biosynthetic Gene Cluster from Verrucosispora sp. SCSIO 07399

Genomic insights into an endophytic Streptomyces sp. VITGV156 for antimicrobial compounds

Endophytic Streptomyces sp. are recognized as a potential resource for valuable natural products but are less explored. This study focused on exploring endophytic Streptomyces species residing within tomato plants (Solanum lycopersicum) harboring genes for the production of a novel class of antibiotics. Our research involved the isolation and characterization of Streptomyces sp. VITGV156, a newly identified endophytic Streptomyces species that produces antimicrobial products. VITGV156 harbors a genome of 8.18 mb and codes 6,512 proteins, of which 4,993 are of known function (76.67%) and 1,519 are of unknown function (23.32%). By employing genomic analysis, we elucidate the genome landscape of this microbial strain and shed light on various BGCs responsible for producing polyketide antimicrobial compounds, with particular emphasis on the antibiotic kendomycin. We extended our study by evaluating the antibacterial properties of kendomycin. Overall, this study provides valuable insights into the genome of endophytic Streptomyces species, particularly Streptomyces sp. VITGV156, which are prolific producers of antimicrobial agents. These findings hold promise for further research and exploitation of pharmaceutical compounds, offering opportunities for the development of novel antimicrobial drugs.

MGCEP 1.0: A Genetic-Engineered Marine-Derived Chassis Cell for a Scaled Heterologous Expression Platform of Microbial Bioactive Metabolites

Marine microorganisms produce a variety of bioactive secondary metabolites, which represent a significant source of novel antibiotics. Heterologous expression is a valuable tool for discovering marine microbial secondary metabolites; however, marine-derived chassis cell is very scarce. Here, we build an efficient plug-and-play marine-derived gene clusters expression platform 1.0 (MGCEP 1.0) by the systematic engineering of the deep-sea-derived Streptomyces atratus SCSIO ZH16. For a proof of concept, four families of microbial bioactive metabolite biosynthetic gene clusters (BGCs), including alkaloids, aminonucleosides, nonribosomal peptides, and polyketides, were efficiently expressed in this platform. Moreover, 19 compounds, including two new angucycline antibiotics, were produced in MGCEP 1.0. Dynamic patterns of global biosynthetic gene expression in MGCEP 1.0 with or without a heterologous gene cluster were revealed at the transcriptome level. The platform MGCEP 1.0 provides new possibilities for expressing microbial secondary metabolites, especially of marine origin.

Recent Advances in the Heterologous Expression of Biosynthetic Gene Clusters for Marine Natural Products

Marine natural products (MNPs) are an important source of biologically active metabolites, particularly for therapeutic agent development after terrestrial plants and nonmarine microorganisms. Sequencing technologies have revealed that the number of biosynthetic gene clusters (BGCs) in marine microorganisms and the marine environment is much higher than expected. Unfortunately, the majority of them are silent or only weakly expressed under traditional laboratory culture conditions. Furthermore, the large proportion of marine microorganisms are either uncultivable or cannot be genetically manipulated. Efficient heterologous expression systems can activate cryptic BGCs and increase target compound yield, allowing researchers to explore more unknown MNPs. When developing heterologous expression of MNPs, it is critical to consider heterologous host selection as well as genetic manipulations for BGCs. In this review, we summarize current progress on the heterologous expression of MNPs as a reference for future research.