title: Production of aromatics in Saccharomyces cerevisiae--a feasibility study.
abstract: Aromatics are amongst the most important bulk feedstocks for the chemical industry, however, no viable bioprocess exists today and production is still dependent on petro-chemistry. In this article the production of aromatic precursors such as p-hydroxybenzoic acid (PHBA) and p-amino benzoic acid (PABA) in Saccharomyces cerevisiae was evaluated using metabolic network analysis. Theoretical mass yields for PHBA and for PABA obtained by metabolic network analysis were 0.58 and 0.53 g g(glucose)⁻¹, respectively. A major setback for microbial production of aromatics is the high toxicity of the products. Therefore, PHBA and PABA toxicity was evaluated in S. cerevisiae. Minimal inhibitory concentrations of 38.3 g L⁻¹ for PHBA and 0.62 g L⁻¹ for PABA were observed. However, PABA toxicity could be alleviated in adaptation experiments. Finally, metabolic engineering was used to create proof of principle first generation strains of S. cerevisiae. Overall accumulation of 650 μM PHBA and 250 μM PABA could be achieved.
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology-AIBN, University of Queensland, Brisbane, Queensland, Australia. j.kromer@uq.edu.au
authors.forename: Jens O
authors.initials: JO
authors.lastname: Krömer
authors.forename: Dariela
authors.initials: D
authors.lastname: Nunez-Bernal
authors.forename: Nils J H
authors.initials: NJ
authors.lastname: Averesch
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hampe
authors.forename: Javier
authors.initials: J
authors.lastname: Varela
authors.forename: Cristian
authors.initials: C
authors.lastname: Varela
mesh_terms: D010129:4-Aminobenzoic Acid / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D005240:Feasibility Studies; D005285:Fermentation; D053858:Metabolic Networks and Pathways; D008826:Microbial Sensitivity Tests; D010226:Parabens / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D010226:Parabens; C038193:4-hydroxybenzoic acid; D010129:4-Aminobenzoic Acid