Pseudomonas putida

About: Pseudomonas putida is a research topic. Over the lifetime, 6854 publications have been published within this topic receiving 230572 citations.

Genetic Basis of the Biodegradation of Salicylate in Pseudomonas

Abstract: The genetic basis of the biodegradation of salicylate in Pseudomonas putida R1 has been studied This strain utilizes the meta pathway for oxidizing salicylate through formation of catechol and 2-hydroxymuconic semialdehyde The enzymes of the meta pathway are induced by salicylate but not by catechol, and the genes specifying these enzymes are clustered The gene cluster can be eliminated from some salicylate-positive cells by treatment with mitomycin C and appears to exist inside the cell as an extrachromosomal element This extrachromosomal gene cluster, termed the SAL plasmid, can be transferred by conjugation from P putida R1 to a variety of other Pseudomonas species

Pseudomonas 2.0: genetic upgrading of P. putida KT2440 as an enhanced host for heterologous gene expression

Abstract: Because of its adaptability to sites polluted with toxic chemicals, the model soil bacterium Pseudomonas putida is naturally endowed with a number of metabolic and stress-endurance qualities which have considerable value for hosting energy-demanding and redox reactions thereof. The growing body of knowledge on P. putida strain KT2440 has been exploited for the rational design of a derivative strain in which the genome has been heavily edited in order to construct a robust microbial cell factory. Eleven non-adjacent genomic deletions, which span 300 genes (i.e., 4.3% of the entire P. putida KT2440 genome), were eliminated; thereby enhancing desirable traits and eliminating attributes which are detrimental in an expression host. Since ATP and NAD(P)H availability – as well as genetic instability, are generally considered to be major bottlenecks for the performance of platform strains, a suite of functions that drain high-energy phosphate from the cells and/or consume NAD(P)H were targeted in particular, the whole flagellar machinery. Four prophages, two transposons, and three components of DNA restriction-modification systems were eliminated as well. The resulting strain (P. putida EM383) displayed growth properties (i.e., lag times, biomass yield, and specific growth rates) clearly superior to the precursor wild-type strain KT2440. Furthermore, it tolerated endogenous oxidative stress, acquired and replicated exogenous DNA, and survived better in stationary phase. The performance of a bi-cistronic GFP-LuxCDABE reporter system as a proxy of combined metabolic vitality, revealed that the deletions in P. putida strain EM383 brought about an increase of >50% in the overall physiological vigour. The rationally modified P. putida strain allowed for the better functional expression of implanted genes by directly improving the metabolic currency that sustains the gene expression flow, instead of resorting to the classical genetic approaches (e.g., increasing the promoter strength in the DNA constructs of interest).

Cis/trans isomerization of fatty acids as a defence mechanism of Pseudomonas putida strains to toxic concentrations of toluene

Abstract: Defence mechanisms of three Pseudomonas putida strains growing in the presence of toluene up to 50%

Anaerobic growth and cyanide synthesis of Pseudomonas aeruginosa depend on anr, a regulatory gene homologous with fnr of Escherichia coli.

Abstract: Summary Anaerobic growth of Pseudomonas aeruginosa on nitrate or arginine requires the anr gene, which codes for a positive control element (ANR) capable of functionally complementing an fnr mutation in Escherichia coli. The anr gene was sequenced; it showed 51% identity with the fnr gene at the amino acid sequence level. Four cysteine residues known to be essential in the FNR protein are conserved in ANR. The anr gene product (deduced Mr 27129) was visualized by the maxicell method and migrated like a 32kDa protein in gel electrophoresis under denaturing conditions. An anr mutant of P. aeruginosa constructed by gene replacement was defective in nitrate respiration, arginine deiminase activity, and hydrogen cyanide biosynthesis, underscoring the diverse metabolic functions of ANR during oxygen limitation. Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas syringae, and Pseudomonas mendocina all had a functional analogue of ANR, indicating that similar anaerobic control mechanisms exist in these bacteria.