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Pseudomonas putida

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


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TL;DR: In vitro and in situ assays demonstrated that 2,4-DCP was toxic to fungal propagules at concentrations below those detected in the soil and did not appear to depress the numbers of total heterotrophic, sporeforming, or chitin-utilizing bacteria.
Abstract: A genetically engineered microorganism, Pseudomonas putida PPO301(pRO103), and the plasmidless parent strain, PPO301, were added at approximately 107 CFU/g of soil amended with 500 ppm of 2,4-dichlorophenoxyacetate (2,4-D) (500 μg/g). The degradation of 2,4-D and the accumulation of a single metabolite, identified by gas chromatography-mass spectrophotometry as 2,4-dichlorophenol (2,4-DCP), occurred only in soil inoculated with PPO301(pRO103), wherein 2,4-DCP accumulated to >70 ppm for 5 weeks and the concentration of 2,4-D was reduced to 400-fold decline in the numbers of fungal propagules and a marked reduction in the rate of CO2 evolution, whereas 2,4-D did not depress either fungal propagules or respiration of the soil microbiota. 2,4-DCP did not appear to depress the numbers of total heterotrophic, sporeforming, or chitin-utilizing bacteria. In vitro and in situ assays conducted with 2,4-DCP and fungal isolates from the soil demonstrated that 2,4-DCP was toxic to fungal propagules at concentrations below those detected in the soil.

85 citations

Journal ArticleDOI
TL;DR: The semicontinuous and continuous degradation of phenol by Pseudomonas putida P8 which was immobilized on activated carbon was investigated and the bacteria grew, especially in the caverns and the entrances of the macropores, whereby the phenol adsorption by theactivated carbon was decreased.
Abstract: The semicontinuous and continuous degradation of phenol by Pseudomonas putida P8 which was immobilized on activated carbon was investigated. The amount of bacteria immobilized on the activated carbon surface dependend on the cell concentration in the suspension and on the type of activated carbon. In a continuous process running for four weeks the biomass, which accumulated in the activated carbon fixed bed, was removed periodically. The average phenol degradation rate in this process was 360 mg/1 h. The degradation activity of the bacteria for phenol, measured by the activity of the catechol-2,3-dioxygenase, was stimulated by the activated carbon. During the fermentation processes the carbon particles were covered with a biofilm. The bacteria grew, especially in the caverns and the entrances of the macropores, whereby the phenol adsorption by the activated carbon was decreased.

85 citations

Journal ArticleDOI
TL;DR: Several types of biodegradation experiments with benzene, toluene, or p-xylene show accumulation of intermediates by Pseudomonas putida F1, which is linked to biomass synthesis and catechol and 3,6-dimethylcatechol, respectively.
Abstract: Several types of biodegradation experiments with benzene, toluene, or p-xylene show accumulation of intermediates by Pseudomonas putida F1. Under aerobic conditions, the major intermediates identified for benzene, toluene, and p-xylene are catechol, 3-methylcatechol, and 3,6-dimethylcatechol, respectively. Oxidations of catechol and 3-methylcatechol are linked to biomass synthesis. When oxygen is limited in the system, phenol (from benzene) and m-cresol and o-cresol (from toluene) accumulate.

85 citations

Journal ArticleDOI
TL;DR: It is proposed that in P. putida methionine is converted to methanethiol and then oxidized to methanesulfonate, which allows P. aeruginosa to grow rapidly with methionines as the sole sulfur source and the reverse transsulfuration pathway between homocysteine and cysteine, with cystathionine as the intermediate, allows it to do so.
Abstract: Cysteine and methionine biosynthesis was studied in Pseudomonas putida S-313 and Pseudomonas aeruginosa PAO1. Both these organisms used direct sulfhydrylation of O -succinylhomoserine for the synthesis of methionine but also contained substantial levels of O -acetylserine sulfhydrylase (cysteine synthase) activity. The enzymes of the transsulfuration pathway (cystathionine γ-synthase and cystathionine β-lyase) were expressed at low levels in both pseudomonads but were strongly upregulated during growth with cysteine as the sole sulfur source. In P. aeruginosa , the reverse transsulfuration pathway between homocysteine and cysteine, with cystathionine as the intermediate, allows P. aeruginosa to grow rapidly with methionine as the sole sulfur source. P. putida S-313 also grew well with methionine as the sulfur source, but no cystathionine γ-lyase, the key enzyme of the reverse transsulfuration pathway, was found in this species. In the absence of the reverse transsulfuration pathway, P. putida desulfurized methionine by the conversion of methionine to methanethiol, catalyzed by methionine γ-lyase, which was upregulated under these conditions. A transposon mutant of P. putida that was defective in the alkanesulfonatase locus ( ssuD ) was unable to grow with either methanesulfonate or methionine as the sulfur source. We therefore propose that in P. putida methionine is converted to methanethiol and then oxidized to methanesulfonate. The sulfonate is then desulfonated by alkanesulfonatase to release sulfite for reassimilation into cysteine.

85 citations

Journal ArticleDOI
TL;DR: These origins comprise a second class of bacterial origins distinct from enteric-type origins: both origins function in both Pseudomonas species, and neither functions in Escherichia coli; enteric origins do not function in either pseudomonad.
Abstract: The bacterial origins of DNA replication have been isolated from Pseudomonas aeruginosa and Pseudomonas putida. These origins comprise a second class of bacterial origins distinct from enteric-type origins: both origins function in both Pseudomonas species, and neither functions in Escherichia coli; enteric origins do not function in either pseudomonad. Both cloned sequences hybridize to chromosomal fragments that show properties expected of replication origins. These origin plasmids are highly unstable, are present at low copy number, and show mutual incompatibility properties. DNA sequence analysis shows that both origins contain several 9-base-pair (bp) E. coli DnaA protein binding sites; four of these are conserved in position and orientation, two of which resemble the R1 and R4 sites of the E. coli origin. Conserved 13-bp direct repeats adjacent to the analogous R1 site are also found. No GATC sites are in the P. aeruginosa origin and only four are in the P. putida origin; no other 4-bp sequence is present in high abundance. Both origins are found between sequences similar to the E. coli and Bacillus subtilis dnaA, dnaN, rpmH, and rnpA genes, a gene organization identical to that for B. subtilis and unlike that of E. coli. A second autonomously replicating sequence was obtained from P. aeruginosa that has some properties of bacterial origins.

85 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023184
2022345
2021182
2020246
2019226
2018206