scholarly journals Degradation of Phenol via Meta Cleavage Pathway by Pseudomonas fluorescens PU1

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Md. Mahiudddin ◽  
A. N. M. Fakhruddin ◽  
Abdullah-Al-Mahin
Keyword(s):  
Phenolic Compounds ◽  
Pseudomonas Fluorescens ◽  
Phenol Degradation ◽  
Carbon Sources ◽  
Soil Microflora ◽  
Ring Cleavage ◽  
Cell Extracts ◽  
Polluted Sites ◽  
Important Means ◽  
Biodegradation Efficiency

Degradation of phenolics by members of soil microflora is an important means by which these substances are removed from the environment thus reducing environmental pollution. Biodegradation by microorganisms offers unique opportunities to destroy or render phenolic compounds. A bacterium, PU1, identified as Pseudomonas fluorescens PU1, was investigated for its ability to grow on and degrade phenols as sole carbon sources in aerobic shaking batch culture. The organism degraded up to 1000 ppm of phenol using meta cleavage pathway. The pathways for phenol degradation were proposed by the identification of metabolites and assay of ring cleavage enzymes in cell extracts. Phenol was degraded via catechol with subsequent metaring cleavage. Cell growth increased as the phenol concentrations increased up to 1000 ppm phenol. The biodegradation efficiency, degradation extent, and metabolic pathway of phenol were determined to provide useful clues for further application of this isolate in the engineered bioremediation systems. The paper's results suggest that Pseudomonas fluorescens PU1 strain could be a good candidate for remediation of phenol contaminants from heavily polluted sites.

scholarly journals Ice-nucleating microorganisms. Part II. Effect of carbon sources on the ice-nucleating activity of Pseudomonas fluorescens KUIN-1.

1987 ◽  
Vol 61 (10) ◽  
pp. 1285-1288
Author(s):  
Hitoshi OBATA ◽  
Kiyonori DOBASHI ◽  
Junichi TANISHITA ◽  
Tai TOKUYAMA
Keyword(s):  
Pseudomonas Fluorescens ◽  
Carbon Sources

Production and Properties of Biosurfactants from a Newly Isolated Pseudomonas fluorescens HW-6 Growing on Hexadecane

2006 ◽  
Vol 61 (7-8) ◽  
pp. 553-559 ◽  
Author(s):  
Evgenia Vasileva-Tonkova ◽  
Danka Galabova ◽  
Emilia Stoimenova ◽  
Zdravko Lalchev
Keyword(s):  
Pseudomonas Fluorescens ◽  
Industrial Wastewater ◽  
High Surface ◽  
Emulsifying Properties ◽  
Effective Surface ◽  
Mineral Oils ◽  
Air Water Interface ◽  
Polluted Sites ◽  
High Concentrations ◽  
High Surface Activity

The newly isolated from industrial wastewater Pseudomonas fluorescens strain HW-6 produced glycolipid biosurfactants at high concentrations (1.4-2.0 g l-1) when grown on hexadecane as a sole carbon source. Biosurfactants decreased the surface tension of the air/ water interface by 35 mN m-1 and possessed a low critical micelle concentration value of 20 mg l-1, which indicated high surface activity. They efficiently emulsified aromatic hydrocarbons, kerosene, n-paraffins and mineral oils. Biosurfactant production contributed to a significant increase in cell hydrophobicity correlated with an increased growth of the strain on hexadecane. The results suggested that the newly isolated strain of Ps. fluorescens and produced glycolipid biosurfactants with effective surface and emulsifying properties are very promising and could find application for bioremediation of hydrocarbon-polluted sites.

scholarly journals Accumulation of α-Keto Acids as Essential Components in Cyanide Assimilation by Pseudomonas fluorescens NCIMB 11764

1998 ◽  
Vol 64 (11) ◽  
pp. 4452-4459 ◽  
Author(s):  
Daniel A. Kunz ◽  
Jui-Lin Chen ◽  
Guangliang Pan
Keyword(s):  
Pseudomonas Fluorescens ◽  
Culture Fluid ◽  
Maximal Activity ◽  
Resonance Spectroscopy ◽  
Keto Acid ◽  
Growth Substrate ◽  
Reaction Products ◽  
Cell Extracts ◽  
Keto Acids ◽  
Essential Components

ABSTRACT Pyruvate (Pyr) and α-ketoglutarate (αKg) accumulated when cells of Pseudomonas fluorescens NCIMB 11764 were cultivated on growth-limiting amounts of ammonia or cyanide and were shown to be responsible for the nonenzymatic removal of cyanide from culture fluids as previously reported (J.-L. Chen and D. A. Kunz, FEMS Microbiol. Lett. 156:61–67, 1997). The accumulation of keto acids in the medium paralleled the increase in cyanide-removing activity, with maximal activity (760 μmol of cyanide removed min−1 ml of culture fluid−1) being recovered after 72 h of cultivation, at which time the keto acid concentration was 23 mM. The reaction products that formed between the biologically formed keto acids and cyanide were unambiguously identified as the corresponding cyanohydrins by 13C nuclear magnetic resonance spectroscopy. Both the Pyr and α-Kg cyanohydrins were further metabolized by cell extracts and served also as nitrogenous growth substrates. Radiotracer experiments showed that CO2 (and NH3) were formed as enzymatic conversion products, with the keto acid being regenerated as a coproduct. Evidence that the enzyme responsible for cyanohydrin conversion is cyanide oxygenase, which was shown previously to be required for cyanide utilization, is based on results showing that (i) conversion occurred only when extracts were induced for the enzyme, (ii) conversion was oxygen and reduced-pyridine nucleotide dependent, and (iii) a mutant strain defective in the enzyme was unable to grow when it was provided with the cyanohydrins as a growth substrate. Pyr and αKg were further shown to protect cells from cyanide poisoning, and excretion of the two was directly linked to utilization of cyanide as a growth substrate. The results provide the basis for a new mechanism of cyanide detoxification and assimilation in which keto acids play an essential role.

scholarly journals Key Aromatic-Ring-Cleaving Enzyme, Protocatechuate 3,4-Dioxygenase, in the Ecologically Important MarineRoseobacter Lineage

2000 ◽  
Vol 66 (11) ◽  
pp. 4662-4672 ◽  
Author(s):  
Alison Buchan ◽  
Lauren S. Collier ◽  
Ellen L. Neidle ◽  
Mary Ann Moran
Keyword(s):  
Aromatic Compounds ◽  
Southern Hybridization ◽  
Ring Cleavage ◽  
Degenerate Pcr ◽  
Cell Extracts ◽  
Aromatic Compound Degradation ◽  
Genes Encoding ◽  
Cleavage Enzyme ◽  
Key Enzyme ◽  
Dioxygenase Activity

ABSTRACT Aromatic compound degradation in six bacteria representing an ecologically important marine taxon of the α-proteobacteria was investigated. Initial screens suggested that isolates in theRoseobacter lineage can degrade aromatic compounds via the β-ketoadipate pathway, a catabolic route that has been well characterized in soil microbes. Six Roseobacter isolates were screened for the presence of protocatechuate 3,4-dioxygenase, a key enzyme in the β-ketoadipate pathway. All six isolates were capable of growth on at least three of the eight aromatic monomers presented (anthranilate, benzoate, p-hydroxybenzoate, salicylate, vanillate, ferulate, protocatechuate, and coumarate). Four of the Roseobacter group isolates had inducible protocatechuate 3,4-dioxygenase activity in cell extracts when grown onp-hydroxybenzoate. The pcaGH genes encoding this ring cleavage enzyme were cloned and sequenced from two isolates,Sagittula stellata E-37 and isolate Y3F, and in both cases the genes could be expressed in Escherichia coli to yield dioxygenase activity. Additional genes involved in the protocatechuate branch of the β-ketoadipate pathway (pcaC,pcaQ, and pobA) were found to cluster withpcaGH in these two isolates. Pairwise sequence analysis of the pca genes revealed greater similarity between the twoRoseobacter group isolates than between genes from eitherRoseobacter strain and soil bacteria. A degenerate PCR primer set targeting a conserved region within PcaH successfully amplified a fragment of pcaH from two additionalRoseobacter group isolates, and Southern hybridization indicated the presence of pcaH in the remaining two isolates. This evidence of protocatechuate 3,4-dioxygenase and the β-ketoadipate pathway was found in all six Roseobacterisolates, suggesting widespread abilities to degrade aromatic compounds in this marine lineage.

The degradation of p-toluenesulfonate by a Pseudomonas

1970 ◽  
Vol 16 (5) ◽  
pp. 309-316 ◽  
Author(s):  
D. D. Focht ◽  
F. D. Williams
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Aromatic Compounds ◽  
Carbon Sources ◽  
Sole Source ◽  
Carbon Chain ◽  
Ring Cleavage ◽  
Resting Cells ◽  
Resting Cell ◽  
Complete Mineralization

A Pseudomonas isolated from sewage was adapted to use p-toluenesulfonate as the sole source of both carbon and sulfur. Very few of over 30 aromatic compounds tested were used for growth as sole carbon sources. Significantly, sulfobenzoate, phenolsulfonates, and isomers of cresolsulfonates did not support growth. Respirometry studies with washed, resting cells showed similar results. In both studies, benzenesulfonate was always used more rapidly than p-toluenesulfonate. The degradation of p-toluenesulfonate was shown to be over 90% of the theoretical value required for complete mineralization to carbon dioxide, water, and sulfate. When resting cells were incubated with 35S-p-toluenesulfonate, the ratio of oxygen uptake to 35S-sulfate liberation remained constant during the complete degradation period. Radiochromatographic analysis showed no 35S-aromatic intermediates in resting-cell supernatants at any time. Resting cells previously incubated with 35S-p-toluenesulfonate liberated two 35S-labeled aromatic intermediates upon disruption. Resting cells incubated with 1-14C-p-toluenesulfonate produced labeled 3-methylcatechol, labeled acetate, and unlabeled pyruvate. The labeled intermediate, 3-methylcatechol, was degraded by cell-free extracts to labeled acetate. Hydroxylation, desulfonation, ring cleavage, and subsequent fissions of the carbon chain occurred in that order; all steps but the first were catalyzed by cell-free extracts.

scholarly journals Interaction of the Srb10 Kinase with Sip4, a Transcriptional Activator of Gluconeogenic Genes in Saccharomyces cerevisiae

2001 ◽  
Vol 21 (17) ◽  
pp. 5790-5796 ◽  
Author(s):  
Olivier Vincent ◽  
Sergei Kuchin ◽  
Seung-Pyo Hong ◽  
Robert Townley ◽  
Valmik K. Vyas ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase Ii ◽  
Transcriptional Repression ◽  
Transcriptional Control ◽  
Carbon Sources ◽  
Transcriptional Activator ◽  
Glucose Limitation ◽  
Cell Extracts ◽  
Rna Polymerase Ii Holoenzyme

ABSTRACT Sip4 is a Zn2Cys6 transcriptional activator that binds to the carbon source-responsive elements of gluconeogenic genes in Saccharomyces cerevisiae. The Snf1 protein kinase interacts with Sip4 and regulates its phosphorylation and activator function in response to glucose limitation; however, evidence suggested that another kinase also regulates Sip4. Here we examine the role of the Srb10 kinase, a component of the RNA polymerase II holoenzyme that has been primarily implicated in transcriptional repression but also positively regulates Gal4. We show that Srb10 is required for phosphorylation of Sip4 during growth in nonfermentable carbon sources and that the catalytic activity of Srb10 stimulates the ability of LexA-Sip4 to activate transcription of a reporter. Srb10 and Sip4 coimmunoprecipitate from cell extracts and interact in two-hybrid assays, suggesting that Srb10 regulates Sip4 directly. We also present evidence that the Srb10 and Snf1 kinases interact with different regions of Sip4. These findings support the view that the Srb10 kinase not only plays negative roles in transcriptional control but also has broad positive roles during growth in carbon sources other than glucose.

para-Hydroxybenzoate supported nitrogen fixation in Azotobacter vinelandii strain OP (13705)

1988 ◽  
Vol 34 (11) ◽  
pp. 1271-1275 ◽  
Author(s):  
Jay B. Peterson ◽  
Lynn S. Peterson
Keyword(s):  
Nitrogen Fixation ◽  
Cytoplasmic Membrane ◽  
Azotobacter Vinelandii ◽  
Nitrogenase Activity ◽  
Molecular Nitrogen ◽  
Carbon Sources ◽  
Gel Filtration ◽  
Cell Extracts ◽  
Reduction Assay ◽  
Membrane Bound

Azotobacter vinelandii cells grew with molecular nitrogen and p-hydroxybenzoate as the sole added nitrogen and carbon sources. Nitrogenase activity in p-hydroxybenzoate grown cells was demonstrated with the acetylene reduction assay. Cell extracts contained the enzymes p-hydroxybenzoate hydroxylase (EC 1.14.13.2) and protocatechuate 3,4-dioxygenase (EC 1.13.1.3); oxygenases associated with p-hydroxybenzoate metabolism. These enzymes separated from respiration particles with gel filtration chromatography, indicating that they are soluble and not membrane bound. This evidence indicates that oxygen enters to the inner face of the cytoplasmic membrane during nitrogen fixation.

Effect of Conventional Carbon Sources on Phenol Degradation by Bacillus sp. CDQ

2013 ◽  
Vol 726-731 ◽  
pp. 301-304 ◽  
Author(s):  
Xi Pu He ◽  
Jie Liu ◽  
Hong Jie Liu ◽  
Sen Sheng Wang ◽  
Wen Hui Xu ◽  
...  
Keyword(s):  
Glucose Concentration ◽  
Sodium Acetate ◽  
Removal Rate ◽  
Phenol Degradation ◽  
Carbon Sources ◽  
Phenol Removal ◽  
Biodegradation Rate ◽  
Phenol Biodegradation ◽  
Noticeable Improvement

The influence on the growth and phenol biodegradation ofBacillussp. CDQ by three different conventional carbon sources were investigated. The results indicated that conventional carbon sources certainly affected the growth of strain CDQ and the biodegradation of phenol. Under the concentration of 1.5 to 3 g L-1, contrasting to the comparison, glucose improved the growth of theBacillussp. CDQ but inhibited the phenol biodegradation byBacillussp. CDQ. And the effect of inhibition increased with increasing glucose concentration. Below 1.5 g L-1, the rate of phenol removal increased with the amount of glucose added. Phenol biodegradation rate obviously decreased in the presence of sodium acetate. Lactose can significantly improve the rate of phenol biodegradation. However, no noticeable improvement on the removal rate of phenol was observed under different concentrations of lactose.

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