Metabolic engineering of E. coli for pyocyanin production

Author(s)

da Silva, Adilson Jose ^{[1, 2]} ; Cunha, Josivan de Souza ^[1] ; Hreha, Teri ^[3] ; Micocci, Kelli Cristina ^[4] ; Selistre-de-Araujo, Heloisa Sobreiro ^[5] ; Barquera, Blanca ^{[3, 2]} ; Koffas, Mattheos A. G. ^{[3, 6, 2]}

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem Engn, BR-13565905 Sao Carlos, SP - Brazil

^[2] Rensselaer Polytech Inst, Ctr Biotechnol & Interdisciplinary Studies, Troy, NY - USA

^[3] Rensselaer Polytech Inst, Dept Biol Sci, Troy, NY 12180 - USA

^[4] Sao Paulo State Univ, Ctr Study Social Insects, BR-13506900 Rio Claro, SP - Brazil

^[5] Univ Fed Sao Carlos, Dept Physiol Sci, BR-13565905 Sao Carlos, SP - Brazil

^[6] Rensselaer Polytech Inst, Dept Chem & Biol Engn, Troy, NY 12180 - USA

• Document type: Journal article
• Source: METABOLIC ENGINEERING; v. 64, p. 15-25, MAR 2021.
• Web of Science Citations: 0

Abstract

Pyocyanin is a secondary metabolite from Pseudomonas aeruginosa that belongs to the class of phenazines, which are aromatic nitrogenous compounds with numerous biological functions. Besides its antifungal and antimicrobial activities, pyocyanin is a remarkable redox-active molecule with potential applications ranging from the pharma industry to the development of microbial fuel cells. Nevertheless, pyocyanin production has been restricted to P. aeruginosa strains, limiting its practical applicability. In this study, the pyocyanin biosynthetic pathway was engineered for the first time for high level production of this compound in a heterologous host. Escherichia coli cells harboring the nine-gene pathway divided into two plasmids were able to produce and secrete pyocyanin at higher levels than some Pseudomonas aeruginosa strains. The influence of culture and induction parameters were evaluated, and the optimized conditions led to an increase of 3.5-fold on pyocyanin accumulation. Pathway balancing was achieved by testing a set of plasmids with different copy numbers to optimize the expression levels of pyocyanin biosynthetic genes, resulting in a fourfold difference in product titer among the engineered strains. Further improvements were achieved by co-expression of Vitreoscilla hemoglobin Vhb, which relieved oxygen limitations and led to a final titer of 18.8 mg/L pyocyanin. These results show promise to use E. coli for phenazines production, and the engineered strain developed here has the potential to be used in electro-fermentation systems where pyocyanin plays a role as electron-shuttle. (AU)

• FAPESP's process: 19/11437-7 - Integrin molecular mechanisms of action during tumor progression and metastasis development: an intercellular approach
• Grantee: Heloisa Sobreiro Selistre de Araújo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/09695-2 - Elucidation of the biosynthetic pathway of korormicin in Pseudoalteromonas JO10 and heterologous production in E. coli
• Grantee: Adilson José da Silva
• Support Opportunities: Scholarships abroad - Research