title: Plasmolysis induced by toluene in a cyoB mutant of Pseudomonas putida.
abstract: The cyoABCDE gene cluster of Pseudomonas putida DOT-T1E encodes a terminal cytochrome oxidase. A 500-bp 'cyoB' DNA fragment was cloned in pCHESI Omega Km and used to generate a cyoB knock-out mutant in vivo. The mutant strain was not limited in the generation of proton-motif force, although when grown on minimal medium with glucose or citrate, the CyoB mutant exhibited a slight increase in duplication time with respect to the wild-type strain. This effect was even more pronounced when toluene was supplied in the gas phase. In consonance with the negative effect of toluene on the growth was the finding that the CyoB mutant was hypersensitive to sudden 0.3% (v/v) toluene shocks, in contrast with the wild-type strain. This effect was particularly exacerbated in cells that reached the stationary phase. The increased sensitivity to solvents of the CyoB mutant did not appear to be related to the inability of the cells to strengthen the membrane package or to induce the efflux pumps in response to the solvent, but rather to solvent-induced plasmolysis that may be triggered by wrinkles in the cytoplasmic membrane at the poles of the mutant cells, and invagination of the outer membranes, which eventually lead to cell death.
authors.affiliation: Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Plant Biochemistry and Molecular and Cellular Biology, E-18008 Granada, Spain.
authors.forename: Estrella
authors.initials: E
authors.lastname: Duque
authors.forename: Vanina
authors.initials: V
authors.lastname: García
authors.forename: Jesús
authors.initials: J
authors.lastname: de la Torre
authors.forename: Patricia
authors.initials: P
authors.lastname: Godoy
authors.forename: Patricia
authors.initials: P
authors.lastname: Bernal
authors.forename: Juan-Luis
authors.initials: JL
authors.lastname: Ramos
mesh_terms: D015139:Blotting, Southern; D002455:Cell Division / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D017931:DNA Primers; D003576:Electron Transport Complex IV / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D016254:Mutagenesis, Insertional; D009154:Mutation / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D016958:Pseudomonas putida / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D014050:Toluene / Q000633:toxicity*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D017931:DNA Primers; D005227:Fatty Acids; D014050:Toluene; D003576:Electron Transport Complex IV; D001616:beta-Galactosidase