Development of a cyanobacterial heterologous polyketide production platform

Abstract

The development of new heterologous hosts for polyketides production represents an excellent opportunity to expand the genomic, physiological, and biochemical backgrounds that better fit the sustainable production of these valuable molecules. Cyanobacteria are particularly attractive for the production of natural compounds because they have minimal nutritional demands and several strains have well established genetic tools. Using the model strain Synechococcus elongatus, a generic platform was developed for the heterologous production of polyketide synthase (PKS)-derived compounds. The versatility of this system is based on interchangeable modules harboring promiscuous enzymes for PKS activation and the production of PKS extender units, as well as inducible circuits for a regulated expression of the PKS biosynthetic gene cluster. To assess the capability of this platform, we expressed the mycobacterial PKS-based mycocerosic biosynthetic pathway to produce multimethyl-branched esters (MBE). This work is a foundational step forward for the production of high value polyketides in a photosynthetic microorganism.

Leveraging synthetic biology for producing bioactive polyketides and non-ribosomal peptides in bacterial heterologous hosts

“…165 Roulet et al have developed genetic tools specifically for polyketide production in S. elongatus PCC 7942 and applied them to the heterologous production of multimethyl-branched esters. 95 Two exceptional studies, described below, demonstrate the capabilities of PCC 7120 and PCC 6803 for producing two bioactive non-ribosomal peptides, lyngbyatoxin A and shinorine, respectively. Lyngbyatoxin A is a cytotoxin and acts as a tumor promoter in mammalian cells by activating protein kinase C, an enzyme that regulates cell proliferation and differentiation.…”

“…94 Even though there are few examples of cyanobacteria being used as a heterologous host for BGCs, genetic tools have been developed for the heterologous production of natural products in these species. [95][96][97][98] Lastly, CRISPR-based genome editing methods are available for all of the heterologous hosts discussed in this review. 60,61,[99][100][101][102][103][104] Common substrates for PKSs and NRPSs include primary metabolites, such as acetyl-CoA, malonyl-CoA, and proteinogenic amino acids.…”

Genetic, Genomics, and Responses to Stresses in Cyanobacteria: Biotechnological Implications

“…In Synechococcus PCC 7942 (Table 2), the most frequently employed chromosomal neutral sites are NSI (GenBank accession n • U30252), NSII (GenBank accession U44761) [253]), and NSIII (GenBank accession ABB56771.1) [254,255]. Photoproduction of isobutyraldehyde [360] Photoproduction of 1-butanol [361,362] Analysis of carboxysomes [363,364] Photoproduction of isopropanol [364] Photoproduction of isobutanol [365] Photoproduction of 3-hydroxypropionic acid [366] Photoproduction of 1,3-propanediol [367] Photoproduction of amorphadiene and squalene [368] Photoproduction of limonene [369] Photoproduction of acetone [370] Photoproduction of isoprene [371] Analysis of gene-expression control systems [372] Photoproduction of 2,3-butanediol [373] Photoproduction of farnesene [374,375] Photoproduction of lactate [376] NSI and NSIII Photoproduction of biomass and sucrose export [377] Photoproduction of a synthetic CO 2 -fixing photorespiratory bypass [378] Photoproduction of 2,3 butanediol [379] Photoproduction of amorphadiene or squalene [380] NSI, NSII, and NSIII Overproduction of transporters to facilitate sugar export [254] Promoter analysis [381] Photoproduction of polyketides [382] Analysis of the influence of pilus biogenesis on the natural transformation [229] psbA1 Photoproduction of ethylene [383] glgc Photoproduction of isobutanol [366]…”

Technical Advances to Accelerate Modular Type I Polyketide Synthase Engineering towards a Retro-biosynthetic Platform

“…Another growth property of interest includes the carbon and energy sources used by the heterologous host. Heterologous hosts such as Pseudomonas putida which consume a wide variety of lignin compounds as a carbon source [31] or the cyanobacterium Synechococcus elongatus, which can use light as an energy source and CO2 as a carbon source [32] have been adapted for the production of PKSs ( Table 1).…”