scholarly journals Simultaneous Degradation of Atrazine and Phenol by Pseudomonas sp. Strain ADP: Effects of Toxicity and Adaptation

2004 ◽  
Vol 70 (4) ◽  
pp. 1907-1912 ◽  
Author(s):  
Grit Neumann ◽  
Riho Teras ◽  
Liis Monson ◽  
Maia Kivisaar ◽  
Frieder Schauer ◽  
...  
Keyword(s):  
Growth Rate ◽  
Degradation Rate ◽  
Cyanuric Acid ◽  
Phenol Degradation ◽  
Degradation Pathway ◽  
Adaptive Responses ◽  
N Source ◽  
Catabolic Genes ◽  
Simultaneous Degradation ◽  
Atrazine Degradation

ABSTRACT The strain Pseudomonas sp. strain ADP is able to degrade atrazine as a sole nitrogen source and therefore needs a single source for both carbon and energy for growth. In addition to the typical C source for Pseudomonas, Na2-succinate, the strain can also grow with phenol as a carbon source. Phenol is oxidized to catechol by a multicomponent phenol hydroxylase. Catechol is degraded via the ortho pathway using catechol 1,2-dioxygenase. It was possible to stimulate the strain in order to degrade very high concentrations of phenol (1,000 mg/liter) and atrazine (150 mg/liter) simultaneously. With cyanuric acid, the major intermediate of atrazine degradation, as an N source, both the growth rate and the phenol degradation rate were similar to those measured with ammonia as an N source. With atrazine as an N source, the growth rate and the phenol degradation rate were reduced to ∼35% of those obtained for cyanuric acid. This presents clear evidence that although the first three enzymes of the atrazine degradation pathway are constitutively present, either these enzymes or the uptake of atrazine is the bottleneck that diminishes the growth rate of Pseudomonas sp. strain ADP with atrazine as an N source. Whereas atrazine and cyanuric acid showed no significant toxic effect on the cells, phenol reduces growth and activates or induces typical membrane-adaptive responses known for the genus Pseudomonas. Therefore Pseudomonas sp. strain ADP is an ideal bacterium for the investigation of the regulatory interactions among several catabolic genes and stress response mechanisms during the simultaneous degradation of toxic phenolic compounds and a xenobiotic N source such as atrazine.

scholarly journals Insights into functional and evolutionary analysis of carbaryl metabolic pathway from Pseudomonas sp. strain C5pp

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Vikas D. Trivedi ◽  
Pramod Kumar Jangir ◽  
Rakesh Sharma ◽  
Prashant S. Phale
Keyword(s):  
Draft Genome ◽  
Degradation Pathway ◽  
Evolutionary Analysis ◽  
Extradiol Dioxygenase ◽  
Transfer Event ◽  
New Family ◽  
New Genes ◽  
Catabolic Genes ◽  
Soil Isolate ◽  
Genes Encoding

Abstract Carbaryl (1-naphthyl N-methylcarbamate) is a most widely used carbamate pesticide in the agriculture field. Soil isolate, Pseudomonas sp. strain C5pp mineralizes carbaryl via 1-naphthol, salicylate and gentisate, however the genetic organization and evolutionary events of acquisition and assembly of pathway have not yet been studied. The draft genome analysis of strain C5pp reveals that the carbaryl catabolic genes are organized into three putative operons, ‘upper’, ‘middle’ and ‘lower’. The sequence and functional analysis led to identification of new genes encoding: i) hitherto unidentified 1-naphthol 2-hydroxylase, sharing a common ancestry with 2,4-dichlorophenol monooxygenase; ii) carbaryl hydrolase, a member of a new family of esterase; and iii) 1,2-dihydroxy naphthalene dioxygenase, uncharacterized type-II extradiol dioxygenase. The ‘upper’ pathway genes were present as a part of a integron while the ‘middle’ and ‘lower’ pathway genes were present as two distinct class-I composite transposons. These findings suggest the role of horizontal gene transfer event(s) in the acquisition and evolution of the carbaryl degradation pathway in strain C5pp. The study presents an example of assembly of degradation pathway for carbaryl.

scholarly journals Plasmid Localization and Organization of Melamine Degradation Genes in Rhodococcus sp. Strain Mel

2011 ◽  
Vol 78 (5) ◽  
pp. 1397-1403 ◽  
Author(s):  
Anthony G. Dodge ◽  
Lawrence P. Wackett ◽  
Michael J. Sadowsky
Keyword(s):  
454 Pyrosequencing ◽  
Minimal Medium ◽  
Doubling Time ◽  
Cyanuric Acid ◽  
Acid Hydrolase ◽  
Content Type ◽  
N Source ◽  
Genes Encoding ◽  
Rhodococcus Sp ◽  
Roche 454

ABSTRACTRhodococcussp. strain Mel was isolated from soil by enrichment and grew in minimal medium with melamine as the sole N source with a doubling time of 3.5 h. Stoichiometry studies showed that all six nitrogen atoms of melamine were assimilated. The genome was sequenced by Roche 454 pyrosequencing to 13× coverage, and a 22.3-kb DNA region was found to contain a homolog to the melamine deaminase genetrzA. Mutagenesis studies showed that the cyanuric acid hydrolase and biuret hydrolase genes were clustered together on a different 17.9-kb contig. Curing and gene transfer studies indicated that 4 of 6 genes required for the complete degradation of melamine were located on an ∼265-kb self-transmissible linear plasmid (pMel2), but this plasmid was not required for ammeline deamination. TheRhodococcussp. strain Mel melamine metabolic pathway genes were located in at least three noncontiguous regions of the genome, and the plasmid-borne genes encoding enzymes for melamine metabolism were likely recently acquired.

Elucidating the Bio Degradation Pathway and Catabolic Genes of B Enzophenone-3, a Xenobiotic, in Rhodococcus Sp. S2-17

2021 ◽  
Author(s):  
Ju Hye Baek ◽  
Kyung Hyun Kim ◽  
Yunhee Lee ◽  
Sang Eun Jeong ◽  
Hyun Mi Jin ◽  
...  
Keyword(s):  
Degradation Pathway ◽  
Catabolic Genes

scholarly journals Novel Pathway for the Degradation of 2-Chloro-4-Nitrobenzoic Acid by Acinetobacter sp. Strain RKJ12

2011 ◽  
Vol 77 (18) ◽  
pp. 6606-6613 ◽  
Author(s):  
Dhan Prakash ◽  
Ravi Kumar ◽  
R. K. Jain ◽  
B. N. Tiwary
Keyword(s):  
Salicylic Acid ◽  
Tricarboxylic Acid Cycle ◽  
Sole Source ◽  
Degradation Pathway ◽  
Ring Cleavage ◽  
Muconic Acid ◽  
Content Type ◽  
Nitrobenzoic Acid ◽  
Catabolic Genes ◽  
Catechol 1,2 Dioxygenase

ABSTRACTThe organismAcinetobactersp. RKJ12 is capable of utilizing 2-chloro-4-nitrobenzoic acid (2C4NBA) as a sole source of carbon, nitrogen, and energy. In the degradation of 2C4NBA by strain RKJ12, various metabolites were isolated and identified by a combination of chromatographic, spectroscopic, and enzymatic activities, revealing a novel assimilation pathway involving both oxidative and reductive catabolic mechanisms. The metabolism of 2C4NBA was initiated by oxidativeorthodehalogenation, leading to the formation of 2-hydroxy-4-nitrobenzoic acid (2H4NBA), which subsequently was metabolized into 2,4-dihydroxybenzoic acid (2,4-DHBA) by a mono-oxygenase with the concomitant release of chloride and nitrite ions. Stoichiometric analysis indicated the consumption of 1 mol O2per conversion of 2C4NBA to 2,4-DHBA, ruling out the possibility of two oxidative reactions. Experiments with labeled H218O and18O2indicated the involvement of mono-oxygenase-catalyzed initial hydrolytic dechlorination and oxidative denitration mechanisms. The further degradation of 2,4-DHBA then proceeds via reductive dehydroxylation involving the formation of salicylic acid. In the lower pathway, the organism transformed salicylic acid into catechol, which was mineralized by theorthoring cleavage catechol-1,2-dioxygenase tocis, cis-muconic acid, ultimately forming tricarboxylic acid cycle intermediates. Furthermore, the studies carried out on a 2C4NBA−derivative and a 2C4NBA+transconjugant demonstrated that the catabolic genes for the 2C4NBA degradation pathway possibly reside on the ∼55-kb transmissible plasmid present in RKJ12.

scholarly journals Nitrogen Control of Atrazine Utilization in Pseudomonas sp. Strain ADP

2003 ◽  
Vol 69 (12) ◽  
pp. 6987-6993 ◽  
Author(s):  
Vicente García-González ◽  
Fernando Govantes ◽  
Liz J. Shaw ◽  
Richard G. Burns ◽  
Eduardo Santero
Keyword(s):  
Wild Type Strain ◽  
Nitrogen Sources ◽  
Degradation Pathway ◽  
Strong Impact ◽  
Soil Microcosms ◽  
Degradation Rates ◽  
Herbicide Atrazine ◽  
Mutant Derivative ◽  
Nitrogen Repression ◽  
Atrazine Degradation

ABSTRACT Pseudomonas sp. strain ADP uses the herbicide atrazine as the sole nitrogen source. We have devised a simple atrazine degradation assay to determine the effect of other nitrogen sources on the atrazine degradation pathway. The atrazine degradation rate was greatly decreased in cells grown on nitrogen sources that support rapid growth of Pseudomonas sp. strain ADP compared to cells cultivated on growth-limiting nitrogen sources. The presence of atrazine in addition to the nitrogen sources did not stimulate degradation. High degradation rates obtained in the presence of ammonium plus the glutamine synthetase inhibitor MSX and also with an Nas− mutant derivative grown on nitrate suggest that nitrogen regulation operates by sensing intracellular levels of some key nitrogen-containing metabolite. Nitrate amendment in soil microcosms resulted in decreased atrazine mineralization by the wild-type strain but not by the Nas− mutant. This suggests that, although nitrogen repression of the atrazine catabolic pathway may have a strong impact on atrazine biodegradation in nitrogen-fertilized soils, the use of selected mutant variants may contribute to overcoming this limitation.

scholarly journals Maintenance Role of a Glutathionyl-Hydroquinone Lyase (PcpF) in Pentachlorophenol Degradation by Sphingobium chlorophenolicum ATCC 39723

2008 ◽  
Vol 190 (23) ◽  
pp. 7595-7600 ◽  
Author(s):  
Yan Huang ◽  
Randy Xun ◽  
Guanjun Chen ◽  
Luying Xun
Keyword(s):  
Degradation Rate ◽  
Tricarboxylic Acid Cycle ◽  
Degradation Pathway ◽  
Tricarboxylic Acid ◽  
Metabolic Intermediate ◽  
Reductive Dehalogenase ◽  
Cell Extracts ◽  
Toxic Pollutant ◽  
Sphingobium Chlorophenolicum

ABSTRACT Pentachlorophenol (PCP) is a toxic pollutant. Its biodegradation has been extensively studied in Sphingobium chlorophenolicum ATCC 39723. All enzymes required to convert PCP to a common metabolic intermediate before entering the tricarboxylic acid cycle have been characterized. One of the enzymes is tetrachloro-p-hydroquinone (TeCH) reductive dehalogenase (PcpC), which is a glutathione (GSH) S-transferase (GST). PcpC catalyzes the GSH-dependent conversion of TeCH to trichloro-p-hydroquinone (TriCH) and then to dichloro-p-hydroquinone (DiCH) in the PCP degradation pathway. PcpC is susceptible to oxidative damage, and the damaged PcpC produces glutathionyl (GS) conjugates, GS-TriCH and GS-DiCH, which cannot be further metabolized by PcpC. The fate and effect of GS-hydroquinone conjugates were unknown. A putative GST gene (pcpF) is located next to pcpC on the bacterial chromosome. The pcpF gene was cloned, and the recombinant PcpF was purified. The purified PcpF was able to convert GS-TriCH and GS-DiCH conjugates to TriCH and DiCH, respectively. The GS-hydroquinone lyase reactions catalyzed by PcpF are rather unusual for a GST. The disruption of pcpF in S. chlorophenolicum made the mutant lose the GS-hydroquinone lyase activities in the cell extracts. The mutant became more sensitive to PCP toxicity and had a significantly decreased PCP degradation rate, likely due to the accumulation of the GS-hydroquinone conjugates inside the cell. Thus, PcpF played a maintenance role in PCP degradation and converted the GS-hydroquinone conjugates back to the intermediates of the PCP degradation pathway.

Degradation of Phenol by Fe3+ Doped Nano-TiO2 Photocatalyst

2013 ◽  
Vol 859 ◽  
pp. 361-364 ◽  
Author(s):  
Jing Wang ◽  
Du Shu Huang ◽  
Wei Liu ◽  
Qing Shan Pan ◽  
Yong Min
Keyword(s):  
Degradation Rate ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Nano Tio2 ◽  
Phenol Solution ◽  
Sol Gel Process ◽  
Two Peaks ◽  
Degradation Properties ◽  
Better Than

Degradation properties of phenol using nano-TiO2 as photocatalyst in aqueous solution were investigated. The effect of annealing temperature and ionic modification on the degradation was studied. The results showed that, 500 °C annealed TiO2 was better than 700 °C annealed. Photocatalyst nano-TiO2 material doped with Fe3+ was prepared quickly by sol-gel process and was used as photocatalyst to degrade phenol solution of 100mg/L under UV irradiation for 3 hours. UV spectrophotometer testing was made and found that two peaks at 210 nm and 270 nm were significantly become low, indicating that the phenol has been degraded. The phenol degradation rate was 94.18%.

Ultrasonic Irradiation Of The Removal Of Linear Alkylbenzene Sulphonates (LAS) From Wastewater

2012 ◽  
Author(s):  
Mohd Ariffin Abu Hassan ◽  
Dionissios Mantzavinos ◽  
Ian S. Metcalfe
Keyword(s):  
Ultrasonic Irradiation ◽  
Surfactant Concentration ◽  
Degradation Rate ◽  
Degradation Mechanism ◽  
Low Frequency ◽  
Degradation Pathway ◽  
H2o2 Production ◽  
Oh Radicals ◽  
Linear Alkylbenzene ◽  
Batch Time

Kesan frekuensi rendah (20 kHz) penyinaran ultrasonik untuk penyingkiran Linear Alkylbenzene Sulphonates (LAS) daripada larutan berair telah dikaji. Penyinaran ultrasonik terhadap tiga kepekatan berbeza LAS iaitu 500 μgmol/l, 750 μgmol/l and 1000 μgmol/l telah dijalankan. Kesemua eksperimen telah dijalankan pada suhu 30°C, pada frekuensi 20 kHz, kuasa pada 125 W dan masa eksperimen selama 120 minit tanpa pengawalan terhadap pH. Hasil kajian mendapati OH· radikal mendominasi proses pengdegradasian LAS. Kadar degradasi awal bertambah dengan bertambahnya kepekatan LAS di dalam skop kajian. Penghasilan H2O2 didapati rendah dengan proses penyinaran ultrasonik terhadap LAS pada kepekatan LAS yang tinggi. Keputusan penyinaran ultrasonik terhadap LAS dengan kehadiran Br¯ sebagai pemakan radikal membuktikan bahawa OH· radikal mendominasi pengdegradasian LAS. Kata kunci: Surfaktan, ultrasonik, sisa air, jumlah karbon organik (TOC) The effect of low frequency (20 kHz) ultrasonic irradiation on the removal of sodium Linear Alkylbenzene Sulphonates (LAS) from aqueous solutions has been investigated. Sonication of three different initial concentrations of LAS, 500 μgmol/l, 750 μgmol/l and 1000 μgmol/l, were performed. All experiments used a temperature of 30°C, frequency of 20 kHz, power of 125 W, a batch time of 120 min and the pH was left uncontrolled. It was found that the main degradation of LAS at micromolar concentrations proceeded via a reaction with OH· radicals. The initial degradation rate increased with an increase in the surfactant concentration over the whole concentration range studied. The sonolysis of LAS showed a strong inhibition of H2O2 production at a higher concentration. Sonication of LAS in the presence of Br¯ suggested that OH· radicals induced degradation pathway was the dominating sonochemical degradation mechanism. Key words: Surfactants, ultrasonic, wastewater, total organic carbon (TOC)

The atzB gene of Pseudomonas sp. strain ADP encodes the second enzyme of a novel atrazine degradation pathway.

1997 ◽  
Vol 63 (3) ◽  
pp. 916-923 ◽  
Author(s):  
K L Boundy-Mills ◽  
M L de Souza ◽  
R T Mandelbaum ◽  
L P Wackett ◽  
M J Sadowsky
Keyword(s):  
Degradation Pathway ◽  
Pseudomonas Sp ◽  
Atrazine Degradation

Phenol Degradation Characteristics and Immobilization of Acinetobacte Strain HY1

2012 ◽  
Vol 549 ◽  
pp. 172-176 ◽  
Author(s):  
Jian Bo Jia ◽  
Yong Yang ◽  
Hu Peng Yu
Keyword(s):  
Degradation Rate ◽  
Phenol Degradation ◽  
Phenol Concentration ◽  
Liquid Volume ◽  
Phenol Solution ◽  
Immobilized Bacteria ◽  
Culture Time

The phenol degradation characteristics and immobilization of an Acinetobacte strain HY1 were carried out. The effects of phenol concentration, temperature, pH and NaCl dosage on the growth of HY1 and phenol degradation rate were investigated. The results showed that When the bacteria was cultured in 0.5 g/L phenol solution at 35 °C and pH 7.5 with shaking speed 120 r/min, liquid volume in flask 50 mL and inoculation amount 20 % for 6 h, the degradation rate of phenol was over 95 %. Compared with free bacteria, immobilized bacteria had a higher phenol degradation rate after a long culture time.

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