title: A Pseudomonas putida double mutant deficient in butanol assimilation: a promising step for engineering a biological biofuel production platform.
abstract: Biological production in heterologous hosts is of interest for the production of the C4 alcohol (butanol) and other chemicals. However, some hurdles need to be overcome in order to achieve an economically viable process; these include avoiding the consumption of butanol and maintaining tolerance to this solvent during production. Pseudomonas putida is a potential host for solvent production; in order to further adapt P. putida to this role, we generated mini-Tn5 mutant libraries in strain BIRD-1 that do not consume butanol. We analyzed the insertion site of the mini-Tn5 in a mutant that was deficient in assimilation of butanol using arbitrary PCR followed by Sanger sequencing and found that the transposon was inserted in the malate synthase B gene. Here, we show that in a second round of mutagenesis a double mutant unable to take up butanol had an insertion in a gene coding for a multisensor hybrid histidine kinase. The genetic context of the histidine kinase sensor revealed the presence of a set of genes potentially involved in butanol assimilation; qRT-PCR analysis showed induction of this set of genes in the wild type and the malate synthase mutant but not in the double mutant.
authors.affiliation: Abengoa Research, Abengoa, C/ Energía Solar 1, Palmas Altas, Sevilla, 41014, Spain sol.cuenca@abengoa.com.
authors.forename: María Del Sol
authors.initials: Mdel S
authors.lastname: Cuenca
authors.affiliation: Abengoa Research, Abengoa, C/ Energía Solar 1, Palmas Altas, Sevilla, 41014, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Molina-Santiago
authors.affiliation: Abengoa Research, Abengoa, C/ Energía Solar 1, Palmas Altas, Sevilla, 41014, Spain.
authors.forename: María R
authors.initials: MR
authors.lastname: Gómez-García
authors.affiliation: Abengoa Research, Abengoa, C/ Energía Solar 1, Palmas Altas, Sevilla, 41014, Spain.
authors.forename: Juan L
authors.initials: JL
authors.lastname: Ramos
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D000440:Butanols / Q000378:metabolism*; D004251:DNA Transposable Elements / Q000235:genetics; D005818:Genetic Engineering / Q000379:methods*; D000071677:Histidine Kinase; D008292:Malate Synthase / Q000235:genetics; D016254:Mutagenesis, Insertional; D011494:Protein Kinases / Q000235:genetics; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism*
chemical_list: D056804:Biofuels; D000440:Butanols; D004251:DNA Transposable Elements; D008292:Malate Synthase; D011494:Protein Kinases; D000071677:Histidine Kinase
keywords: Pseudomonas putida; butanol assimilation; histidine kinase; malate synthase B; mutant library