A New Pseudomonas aeruginosa Isolate Enhances Its Unusual 1,3-Propanediol Generation from Glycerol in Bioelectrochemical System

Author(s)

Narcizo, Julia Pereira ; Mancilio, Lucca Bonjy Kikuti ; Pedrino, Matheus ; Guazzaroni, Maria-Eugenia ; de Andrade, Adalgisa Rodrigues ; Reginatto, Valeria

• Document type: Journal article
• Source: CATALYSTS; v. 13, n. 7, p. 13-pg., 2023-07-01.

Abstract

The ability of some bacteria to perform Extracellular Electron Transfer (EET) has been explored in bioelectrochemical systems (BES) to obtain energy or chemicals from pure substances or residual substrates. Here, a new pyoverdine-producing Pseudomonas aeruginosa strain was isolated from an MFC biofilm oxidizing glycerol, a by-product of biodiesel production. Strain EL14 was investigated to assess its electrogenic ability and products. In an open circuit system (fermentation system), EL14 was able to consume glycerol and produce 1,3-propanediol, an unusual product from glycerol oxidation in P. aeruginosa. The microbial fuel cell (MFC) EL14 reached a current density of 82.4 mA m(-2) during the first feeding cycle, then dropped sharply as the biofilm fell off. Cyclic voltammetry suggests that electron transfer to the anode occurs indirectly, i.e., through a redox substance, with redox peak at 0.22 V (vs Ag/AgCl), and directly probably by membrane redox proteins, with redox peak at 0.05 V (vs Ag/AgCl). EL14 produced added-value bioproducts, acetic and butyric acids, as well as 1,3 propanediol, in both fermentative and anodic conditions. However, the yield of 1,3-PDO from glycerol was enhanced from 0.57 to 0.89 (mol of 1,3-PDO mol(-1) of glycerol) under MFC conditions compared to fermentation. This result was unexpected, since successful 1,3-PDO production is not usually associated with P. aeruginosa glycerol metabolism. By comparing EL14 genomic sequences related to the 1,3-PDO biosynthesis with P. aeruginosa reference strains, we observed that strain EL14 has three copies of the dhaT gene (1,3-propanediol dehydrogenase a different arrangement compared to other Pseudomonas isolates). Thus, this work functionally characterizes a bacterium never before associated with 1,3-PDO biosynthesis, indicating its potential for converting a by-product of the biodiesel industry into an emerging chemical product. (AU)

• FAPESP's process: 21/07294-6 - Contribution of Pseudomonas aeruginosa strains to bioelectrochemicals systems for obtaining energy and products from glycerol
• Grantee: Ana Clara Bonizol Zani
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 21/01655-7 - Resistome, plasmidome and virulome of Enterobacterales isolated from the environment carrying mcr-like genes
• Grantee: Eliana Guedes Stehling
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/09375-3 - Development of new microbial platforms tolerant to lignocellulosic biomass hydrolysates
• Grantee: Matheus Pedrino Gonçalves
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 22/04024-0 - Cofermentation of organic and inorganic residues in biological and bioelectrochemical systems for obtaining bioproducts and electricity
• Grantee: Valeria Reginatto Spiller
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 21/01748-5 - Discovery and development of new non-model bacterial chassis for biotechnological applications
• Grantee: María Eugenia Guazzaroni
• Support Opportunities: Research Projects - Thematic Grants