title: The impact of succinate trace on pWW0 and ortho-cleavage pathway transcription in Pseudomonas putida mt-2 during toluene biodegradation.
abstract: Toluene is a pollutant catabolised through the interconnected pWW0 (TOL) and ortho-cleavage pathways of Pseudomonas putida mt-2, while upon succinate and toluene mixtures introduction in batch cultures grown on M9 medium, succinate was previously reported as non-repressing. The effect of a 40 times lower succinate concentration, as compared to literature values, was explored through systematic real-time qPCR monitoring of transcriptional kinetics of the key TOL Pu, Pm and ortho-cleavage PbenR, PbenA promoters in mixed-substrate experiments. Even succinate trace inhibited transcription leading to bi-modal promoters expression. Potential carbon catabolite repression mechanisms and novel expression patterns of promoters were unfolded. Lag phase was shortened and biomass growth levels increased compared to sole toluene biodegradation suggesting enhanced pollutant removal efficiency. The study stressed the noticeable effect of a preferred compound's left-over on the main route of a bioprocess, revealing the beneficiary supply of low preferred substrates concentrations to design optimal bioremediation strategies.
authors.affiliation: Department of Chemical Engineering, South Kensington Campus, Imperial College London, SW7 2AZ London, UK.
authors.forename: Argyro
authors.initials: A
authors.lastname: Tsipa
authors.affiliation: Department of Environmental Science and Technology, Cyprus University of Technology, 30 Archbishop Kuprianou Str., 3036 Limassol, Cyprus.
authors.forename: Michalis
authors.initials: M
authors.lastname: Koutinas
authors.affiliation: Department of Chemical Engineering, South Kensington Campus, Imperial College London, SW7 2AZ London, UK.
authors.forename: Spyros I
authors.initials: SI
authors.lastname: Vernardis
authors.affiliation: Department of Chemical Engineering, South Kensington Campus, Imperial College London, SW7 2AZ London, UK. Electronic address: a.mantalaris@imperial.ac.uk.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Mantalaris
mesh_terms: D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental; D019149:Bioreactors; D004785:Environmental Pollutants / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007700:Kinetics; D053858:Metabolic Networks and Pathways; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism*; D014050:Toluene / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004785:Environmental Pollutants; D013386:Succinates; D014050:Toluene
keywords: Ortho-cleavage pathway; Pseudomonas putida mt-2; Succinate trace; TOL plasmid; Toluene