title: Catechol biosynthesis from glucose in Escherichia coli anthranilate-overproducer strains by heterologous expression of anthranilate 1,2-dioxygenase from Pseudomonas aeruginosa PAO1.
abstract: BACKGROUND
  The aromatic compound catechol is used as a precursor of chemical products having multiple applications. This compound is currently manufactured by chemical synthesis from petroleum-derived raw materials. The capacity to produce catechol is naturally present in several microbial species. This knowledge has been applied to the generation of recombinant Escherichia coli strains that can produce catechol from simple carbon sources.
  
  
  RESULTS
  Several strains derived from E. coli W3110 trpD9923, a mutant that overproduces anthranilate, were modified by transforming them with an expression plasmid carrying genes encoding anthranilate 1,2-dioxygenase from Pseudomonas aeruginosa PAO1. The additional expression of genes encoding a feedback inhibition resistant version of 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase and transketolase from E. coli, was also evaluated. Generated strains were characterized in complex or minimal medium in shake-flask and fed-batch bioreactor cultures and incubation temperatures ranging from 37 to 28°C. These experiments enabled the identification of culture conditions for the production of 4.47 g/L of catechol with strain W3110 trpD9923, expressing 1,2-dioxygenase, DAHP synthase and transketolase. When considering the amount of glucose consumed, a yield of 16% was calculated, corresponding to 42% of the theoretical maximum as determined by elementary node flux analysis.
  
  
  CONCLUSIONS
  This work demonstrates the feasibility of applying metabolic engineering for generating E. coli strains for the production of catechol from glucose via anthranilate. These results are a starting point to further optimize environmentally-compatible production capacity for catechol and derived compounds.
authors.affiliation: Laboratorio de Biología Integrativa de Plantas y Microorganismos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Av. Preparatoria s/n, Col., Agronómica, CP 98066, Zacatecas, Mexico. balderas.victor@gmail.com.
authors.forename: Víctor E
authors.initials: VE
authors.lastname: Balderas-Hernández
authors.affiliation: Departamento de Tecnología Ambiental, Universidad Politécnica del Estado de Morelos, Jiutepec, Morelos, Mexico. ltrevino@upemor.edu.mx.
authors.forename: Luis G
authors.initials: LG
authors.lastname: Treviño-Quintanilla
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca, Morelos, CP 62271, Mexico. ginah@ibt.unam.mx.
authors.forename: Georgina
authors.initials: G
authors.lastname: Hernández-Chávez
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca, Morelos, CP 62271, Mexico. alfredo@ibt.unam.mx.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Martinez
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca, Morelos, CP 62271, Mexico. bolivar@ibt.unam.mx.
authors.forename: Francisco
authors.initials: F
authors.lastname: Bolívar
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo, Postal 510-3, Cuernavaca, Morelos, CP 62271, Mexico. gosset@ibt.unam.mx.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Gosset
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D002396:Catechols / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics*; D062367:ortho-Aminobenzoates / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002396:Catechols; D062367:ortho-Aminobenzoates; C031385:anthranilic acid; D006899:Mixed Function Oxygenases; C023440:anthranilate 2,3-dioxygenase(deaminating); D005947:Glucose; C034221:catechol