scholarly journals Non-invasivein situmonitoring and quantification of TOL plasmid segregational loss withinPseudomonas putidabiofilms

2013 ◽  
Vol 110 (11) ◽  
pp. 2949-2958 ◽  
Author(s):  
Hongyan Ma ◽  
Kristy N. Katzenmeyer ◽  
James D. Bryers
Keyword(s):  
Tol Plasmid

scholarly journals Conjugal TOL Transfer from Pseudomonas putida to Pseudomonas aeruginosa: Effects of Restriction Proficiency, Toxicant Exposure, Cell Density Ratios, and Conjugation Detection Method on Observed Transfer Efficiencies

2005 ◽  
Vol 71 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Catalina Arango Pinedo ◽  
Barth F. Smets
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pseudomonas Putida ◽  
Strong Dependence ◽  
Plasmid Transfer ◽  
Mass Action ◽  
Tol Plasmid ◽  
Toxicant Exposure ◽  
Transfer Frequency ◽  
Cell Densities

ABSTRACT The effects of restriction proficiency and premating exposure to toxicants on conjugal transfer of the TOL plasmid between Pseudomonas spp. was investigated by examinations of filter matings. A Pseudomonas putida KT2442-derived strain carrying a gfp-tagged variant of the TOL plasmid was used as a donor, and both restriction-deficient (PAO1162N) and -proficient (PAO2002N) Pseudomonas aeruginosa strains were used as recipients. The in situ enumeration of conjugation events allowed us to obtain frequency estimates that were unbiased by transconjugant growth or plasmid retransfer. We observed a strong dependence of the plasmid transfer frequency on the initial donor-to-recipient ratio of surface matings, which invalidated the use of mass action-based plasmid transfer kinetic estimators. Careful control of the initial parental cell densities permitted evaluations of the true effects of restriction proficiency and toxicant exposure on TOL transfer. At standard donor-to-recipient ratios (10−3 for PAO1162N and 2 � 101 for PAO2002N) and total cell densities (105 cells/mm2 for PAO1162N and 106 cells/mm2 for PAO2002N), plasmid transfer frequencies without toxicant exposure were approximately 10−7 (events/mm2)−1 for PAO1162N and 10−11 (events/mm2)−1 for PAO2002N based on in situ observations of conjugation events. The enumeration of transconjugants via selective plating yielded transfer frequencies that were up to 1 order of magnitude lower. Premating exposure to sodium dodecyl sulfate (1 to 10 mM) significantly increased the transfer frequency for the restriction-proficient strain PAO2002N (P < 0.05) but not for the restriction-deficient strain PAO1162N. On the other hand, premating exposure to ethanol, toluene, or phenol had no positive effect on the plasmid transfer frequency. Clearly, restriction proficiency provides a strong barrier to interspecific transfer of the TOL plasmid, and this barrier was only marginally attenuated by recipient exposure to toxicants within the ranges examined.

scholarly journals Functional Domains of the TOL Plasmid Transcription Factor XylS

2000 ◽  
Vol 182 (4) ◽  
pp. 1118-1126 ◽  
Author(s):  
Niilo Kaldalu ◽  
Urve Toots ◽  
Victor de Lorenzo ◽  
Mart Ustav
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Dependent Manner ◽  
Tol Plasmid ◽  
Terminal Fragment ◽  
Central Regions ◽  
Basic Features ◽  
Regulatory Functions

ABSTRACT The alkylbenzoate degradation genes of Pseudomonas putida TOL plasmid are positively regulated by XylS, an AraC family protein, in a benzoate-dependent manner. In this study, we used deletion mutants and hybrid proteins to identify which parts of XylS are responsible for the DNA binding, transcriptional activation, and benzoate inducibility. We found that a 112-residue C-terminal fragment of XylS binds specifically to the Pm operator in vitro, protects this sequence from DNase I digestion identically to the wild-type (wt) protein, and activates the Pm promoter in vivo. When overexpressed, that C-terminal fragment could activate transcription as efficiently as wt XylS. All the truncations, which incorporated these 112 C-terminal residues, were able to activate transcription at least to some extent when overproduced. Intactness of the 210-residue N-terminal portion was found to be necessary for benzoate responsiveness of XylS. Deletions in the N-terminal and central regions seriously reduced the activity of XylS and caused the loss of effector control, whereas insertions into the putative interdomain region did not change the basic features of the XylS protein. Our results confirm that XylS consists of two parts which probably interact with each other. The C-terminal domain carries DNA-binding and transcriptional activation abilities, while the N-terminal region carries effector-binding and regulatory functions.

Excision of the 40kb segment of the TOL plasmid from Pseudomonas putida mt-2 involves direct repeats

1981 ◽  
Vol 184 (1) ◽  
pp. 97-101 ◽  
Author(s):  
Pierre Meulien ◽  
Robert G. Downing ◽  
Paul Broda
Keyword(s):  
Pseudomonas Putida ◽  
Direct Repeats ◽  
Tol Plasmid

scholarly journals Identification of chromosomally integrated TOL DNA in cured derivatives of Pseudomonas putida PAW1

1982 ◽  
Vol 152 (2) ◽  
pp. 911-914
Author(s):  
P Meulien ◽  
P Broda
Keyword(s):  
Pseudomonas Putida ◽  
Parental Strain ◽  
Chromosomal Dna ◽  
Tol Plasmid ◽  
Derivatives Of

Some plasmid-free Tol- strains derived from Pseudomonas putida PAW1 (which carries the TOL plasmid pWW0) have a segment of TOL DNA located chromosomally. Of three independently isolated strains, PAW86 had an integrated TOL segment of 16 kilobases and PAW85 had two copies of this segment in different chromosomal locations, whereas the chromosomal DNA of PAW82 showed no homology with the TOL plasmid. In cultures of the parental strain, it appears that a 56-kilobase TOL DNA segment is located chromosomally in some cells.

scholarly journals Overproduction of the xylS gene product and activation of the xylDLEGF operon on the TOL plasmid.

1987 ◽  
Vol 169 (8) ◽  
pp. 3587-3592 ◽  
Author(s):  
S Inouye ◽  
A Nakazawa ◽  
T Nakazawa
Keyword(s):  
Gene Product ◽  
Tol Plasmid
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