Expression of the
            <i>Pseudomonas putida</i>
            OCT Plasmid Alkane Degradation Pathway Is Modulated by Two Different Global Control Signals: Evidence from Continuous Cultures

Dinamarca, M. Alejandro; Aranda-Olmedo, Isabel; Puyet, Antonio; Rojo, Fernando

doi:10.1128/jb.185.16.4772-4778.2003

Cited by 62 publications

(82 citation statements)

References 33 publications

(41 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Several reports of bacteria metabolizing different organic contaminants indicate that the mechanism(s) of carbon catabolite repression of biodegradative operons is different from the cyclic AMP-dependent mechanism, which is well characterized for enteric bacteria (2,9,11,15,33,38). In addition, more than one global regulatory system may regulate expression of biodegradative genes within the same bacteria (9,14).…”

mentioning

confidence: 99%

Regulation of Tetralin Biodegradation and Identification of Genes Essential for Expression of thn Operons

et al. 2004

View full text Add to dashboard Cite

The tetralin biodegradation genes of Sphingomonas macrogolitabida strain TFA are clustered in two closely linked and divergent operons. To analyze expression of both operons under different growth conditions, transcriptional and translational gene fusions of the first genes of each operon to lacZ have been constructed in plasmids unable to replicate in Sphingomonas and integrated by recombination into the genome of strain TFA. Expression analysis indicated that the transcription of both genes is induced in similar ways by the presence of tetralin. Gene expression in both operons is also subjected to overimposed catabolic repression. Two additional genes named thnR and thnY have been identified downstream of thnCA3A4 genes. ThnR is similar to LysR-type regulators, and mutational analysis indicated that ThnR is strictly required for expression of the thn operons. Unlike other LysR-type regulators, ThnR does not repress its own synthesis. In fact, ThnR activates its own expression, since thnR is cotranscribed with the thnCA3A4 genes. ThnY is similar to the ferredoxin reductase components of dioxygenase systems and shows the fer2 domain, binding a Cys 4 [2Fe-2S] iron sulfur center, and the FAD-binding domain, common to those reductases. However, it lacks the NADbinding domain. Intriguingly, ThnY has a regulatory role, since it is also strictly required for expression of the thn operons. Given the similarity of ThnY to reductases and the possibility of its being present in the two redox states, it is tempting to speculate that ThnY is a regulatory component connecting expression of the thn operons to the physiological status of the cell.The organic solvent tetralin (1,2,3,4-tetrahydronaphthalene) is a bicyclic molecule composed of an aromatic and an alicyclic moiety, which share two carbon atoms. Tetralin is widely used as a degreasing agent and solvent for fats, resins, and waxes, as a substitute for turpentine in paints, lacquers, and shoe polishes, and also in the petrochemical industry in connection with coal liquefaction (19). A concentration of tetralin higher than 100 M inhibits bacterial growth (44). Its toxicity is partly due to its lipophilic character, which results in its accumulation in the cell membranes, thus leading to changes in their structure and function (46,47). In addition, tetralin also forms toxic hydroperoxides in the cell (17).A few bacterial strains which are able to aerobically grow on tetralin as the only carbon and energy source have been isolated (44). By the identification of accumulated intermediates, several reports suggest that some bacteria, such as Pseudomonas stutzeri AS39 (43), initially hydroxylate and further oxidize the alicyclic ring whereas others, such as Corynebacterium sp. strain C125 (45), initially dioxygenate the aromatic ring, thus indicating that aerobic metabolism of tetralin can be performed in different ways. Metabolism of tetralin has been best characterized in Sphingomonas macrogolitabida strain TFA. Biodegradation of tetralin by the strain TFA involves initial...

show abstract

mentioning

confidence: 99%

Regulation of Tetralin Biodegradation and Identification of Genes Essential for Expression of thn Operons

et al. 2004

View full text Add to dashboard Cite

show abstract

“…One of them relies on the global regulatory protein Crc [218], while the other one apparently receives information from the cytochrome o ubiquinol oxidase (Cyo), a component of the electron transport chain [227,228]. However, in cells grown in a minimal salts medium containing succinate as the carbon source, the role of Crc is minor and the inhibitory effect derives mainly from the Cyo terminal oxidase [218,227].…”

Section: Catabolite Repression Controlmentioning

confidence: 99%

“…However, in cells grown in a minimal salts medium containing succinate as the carbon source, the role of Crc is minor and the inhibitory effect derives mainly from the Cyo terminal oxidase [218,227].…”

Section: Catabolite Repression Controlmentioning

confidence: 99%

“…In the absence of alkanes, AlkS is expressed from promoter PalkS1 and since AlkS acts as a repressor of its own promoter, it allows for low expression levels. In the presence of C 5 -C 10 alkanes, AlkS activates expression of its own gene from PalkS2, in order to achieve AlkS levels that are high enough to activate the expression of the alkBFGHJKL operon from the PalkB promoter [166,216,217,223,224].Pseudomonas putida GPo1 grows optimally on C 5 -C 10 alkanes, but can use C 3 -C 4 and C 11 -C 13 alkanes as well, although growth is much slower and shows a long lag time [154,165] When cells are grown in the LB complete medium, the catabolite repression of the alkane-degradation genes depends on the additive effects of two global regulation systems.One of them relies on the global regulatory protein Crc [218], while the other one apparently receives information from the cytochrome o ubiquinol oxidase (Cyo), a component of the electron transport chain [227,228]. However, in cells grown in a minimal salts medium containing succinate as the carbon source, the role of Crc is minor and the inhibitory effect derives mainly from the Cyo terminal oxidase [218,227].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Monooxygenases involved in the n-alkanes metabolism by Rhodococcus sp. BCP1: molecular characterization and expression of alkB gene

Cappelletti

Fedi

Honda

et al. 2010

Journal of Biotechnology

View full text Add to dashboard Cite

Discussion 107 Summary 113Chapter 5 -Analysis of the alkB gene expression Summary 157Chapter 6 -Proteomic analysis of n-alkanes growth of Rhodococcus sp. BCP1 Chapter 1 -General Introduction PrefaceThe quality of life on Earth is tightly related with the overall quality of the environment [1]. During the last century it was commonly believed that the abundance of land and resources were unlimited and it was rarely acknowledged that the production, use, and disposal of hazardous substances had environmental and health effects [1][2][3]. Owing to this, human activity has deliberately or inadvertently released into waters and soil a variety of toxic compounds as refrigerants, paints, solvents, herbicides and pesticides that can cause considerable environmental pollution and human health problems as a result of their persistence, toxicity, and transformation into hazardous metabolites [4,5]. Very soon, however, it became clear how the carelessness and negligence in handling the industrial wastes and gas emissions had caused dramatic effect on the nature and on human health [1].Nowadays, the concern about the global warming and the climate changing induced the government regulatory agencies to establish procedures for assessing the environmental impact and health hazards of chemicals and for controlling/limiting their utilization.International efforts have been applied to remedy many contaminated sites all over the world, either as a response to the risk of adverse health or environmental effects caused by contamination or to enable the site to be redeveloped for use [5]. In response to public and government concern and because of the intriguing research problems presented, environmental scientists, biologists and chemists have been giving increased attention to identifying and determining the behavior and fate of organic compounds in natural ecosystems [5].Bioremediation procedures offer an economical and effective possibility to degrade or render innocuous toxic pollutants using natural biological activity [1]. By definition, bioremediation implies the use of living organisms, primarily microorganisms, to degrade the Since contaminant compounds are transformed by living organisms through reactions that take place as a part of their metabolic processes, environmental biotechnology focuses on the development of techniques to optimize environmental parameters to allow these metabolic pathways to proceed faster and, therefore, to improve the bio-degradation [1]. As a result, the removal of the contaminated soil can be necessary to let the biodegradation proceed in controlled sites (such as bioreactors). These ex situ approaches provide optimal conditions out one single step of the entire bio-degradation process. Hydrocarbons in the environmentHydrocarbons are energy-rich organic compounds consisting of carbon and hydrogen atoms and they can be saturated (only single C-H bounds) or unsaturated (one ore more double or triple C-H bounds). Alkanes are saturated hydrocarbons with the general formula C n H 2n+2 ; they can b...

show abstract

“…Since many of these catabolic genes can be carried by plasmids, it was unclear whether the number of organisms containing these genes increased, or if the number of genetic elements present in the community increased (50). the genes responsible for alkanes and aromatics biodegradation pathways are usually arranged in clusters (operons) in mobile genetic elements (e.g., plasmids or transposons) (7,8,39). Gene clusters contain catabolic genes (encode enzymes for catabolic pathways), transport genes (responsible for active uptake of the compound) and regulatory genes (adjust expression of the catabolic and transport genes to the presence of the compound to be degraded) (6,7).…”

Section: Specific Amplification Of Hae1 (Hydrophobe/amphiphile Effluxmentioning

confidence: 99%

Adaptative Response ofShewanella PutrefaciensandPseudomonas Aeruginosato Toxic Organic Solvents

Lazaroaie¹

2010

Biotechnology & Biotechnological Equipment

View full text Add to dashboard Cite

Expression of the Pseudomonas putida OCT Plasmid Alkane Degradation Pathway Is Modulated by Two Different Global Control Signals: Evidence from Continuous Cultures

Cited by 62 publications

References 33 publications

Regulation of Tetralin Biodegradation and Identification of Genes Essential for Expression of thn Operons

Regulation of Tetralin Biodegradation and Identification of Genes Essential for Expression of thn Operons

Monooxygenases involved in the n-alkanes metabolism by Rhodococcus sp. BCP1: molecular characterization and expression of alkB gene

Adaptative Response ofShewanella PutrefaciensandPseudomonas Aeruginosato Toxic Organic Solvents

Contact Info

Product

Resources

About