Impact of the composition of the bacterial population and additional carbon source on the pathway and kinetics of degradation of endosulfan isomers

2017 ◽  
Vol 19 (7) ◽  
pp. 964-974 ◽  
Author(s):  
Swatantra Pratap Singh ◽  
Saumyen Guha ◽  
Purnendu Bose
Keyword(s):  
Carbon Source ◽  
Organochlorine Pesticide ◽  
Bacterial Population ◽  
Bacterial Degradation ◽  
Kinetics Of Degradation ◽  
Kinetics Of ◽  
Additional Carbon Source

Abiotic and bacterial degradation is presented for the two isomers α- and β- of the organochlorine pesticide endosulfan, denoted as ES-1 and ES-2, respectively.

The Characteristics and Kinetics of 4-CP with Pb2+ Biodegradation by Fusarium sp.

2013 ◽  
Vol 726-731 ◽  
pp. 2506-2509
Author(s):  
Xiao Xiao Wang ◽  
Xiao Qin Yu ◽  
Jun Ya Pan ◽  
Ji Wu Li
Keyword(s):  
Carbon Source ◽  
Kinetic Equations ◽  
Order Reaction ◽  
Zero Order ◽  
Biodegradation Rate ◽  
Reaction Equation ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Additional Carbon Source

The effects of Pb2+concentration, pH and additional carbon source on biodegradation of 4-chlorophenol (4-CP) byFusariumsp. were investigated, and the characteristic and kinetic of 4-CP biodegradation were analyzed. It was concluded that 4-CP biodegradation rate byFusariumsp. decreased a little at concentration of Pb2+0.20 mg/L and 4-CP 50 mg/L. The suitable biodegradation pH was range from 6 to 7. Additional carbon source (phenol) might increase the rate of 4-CP biodegradation. The kinetic equations of 4-CP biodegradation were well accord with the zero order reaction equation at different concentration of Pb2+.

scholarly journals Biodegradation of the Polyketide Toxin Cercosporin

2002 ◽  
Vol 68 (9) ◽  
pp. 4173-4181 ◽  
Author(s):  
Thomas K. Mitchell ◽  
William Scott Chilton ◽  
Margaret E. Daub
Keyword(s):  
Xanthomonas Campestris ◽  
Culture Medium ◽  
Plant Pathogens ◽  
Spectroscopic Analysis ◽  
Bacterial Degradation ◽  
Pathogenicity Determinant ◽  
Kinetics Of Degradation ◽  
Oxygen Insertion ◽  
Kinetics Of ◽  
Cytochrome P 450

ABSTRACT Cercosporin is a non-host-specific polyketide toxin produced by many species of plant pathogens belonging to the genus Cercospora. This red-pigmented, light-activated toxin is an important pathogenicity determinant for Cercospora species. In this study, we screened 244 bacterial isolates representing 12 different genera for the ability to degrade cercosporin. Cercosporin degradation was determined by screening for the presence of cleared zones surrounding colonies on cercosporin-containing culture medium and was confirmed by assaying the kinetics of degradation in liquid medium. Bacteria belonging to four different genera exhibited the cercosporin-degrading phenotype. The isolates with the greatest cercosporin-degrading activity belonged to Xanthomonas campestris pv. zinniae and X. campestris pv. pruni. Isolates of these pathovars removed over 90% of the cercosporin from culture medium within 48 h. Bacterial degradation of red cercosporin was accompanied by a shift in the color of the growth medium to brown and then green. The disappearance of cercosporin was accompanied by the appearance of a transient green product, designated xanosporic acid. Xanosporic acid and its more stable lactone derivative, xanosporolactone, are nontoxic to cercosporin-sensitive fungi and to plant tissue and are labile in the presence of light. Detailed spectroscopic analysis (to be reported in a separate publication) of xanosporolactone revealed that cercosporin loses one methoxyl group and gains one oxygen atom in the bacterial conversion. The resulting chromophore (4,9-dihydroxy-3-oxaperlylen-10H-10-one) has never been reported before but is biosynthetically plausible via oxygen insertion by a cytochrome P-450 enzyme.

scholarly journals Comparative Study of Chemical Stability of Two H1Antihistaminic Drugs, Terfenadine and ItsIn VivoMetabolite Fexofenadine, Using LC-UV Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Anna Gumieniczek ◽  
Anna Berecka-Rycerz ◽  
Rafał Pietraś ◽  
Izabela Kozak ◽  
Karolina Lejwoda ◽  
...  
Keyword(s):  
Comparative Study ◽  
Chemical Stability ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of Degradation ◽  
Effects Of Temperature ◽  
High Doses ◽  
Antihistaminic Drugs ◽  
Kinetics Of

A comparative study of chemical stability of terfenadine (TER) and itsin vivometabolite fexofenadine (FEX) was performed. Both TER and FEX were subjected to high temperature at different pH and UV/VIS light at different pH and then quantitatively analyzed using new validated LC-UV methods. These methods were used to monitor the degradation processes and to determine the kinetics of degradation for both the compounds. As far as the effects of temperature and pH were concerned, FEX occurred more sensitive to degradation than TER. As far as the effects of UV/VIS light and pH were concerned, the both drugs were similarly sensitive to high doses of light. Using all stress conditions, the processes of degradation of TER and FEX followed the first-order kinetics. The results obtained for these two antihistaminic drugs could be helpful in developing their new derivatives with higher activity and stability at the same time.

The Kinetics of Degradation of Chloramphenicol in Solution

1954 ◽  
Vol 43 (3) ◽  
pp. 129-134 ◽  
Author(s):  
Takeru Higuchi ◽  
Charles D. Bias ◽  
Arnold D. Marcus
Keyword(s):  
Kinetics Of Degradation ◽  
Kinetics Of

Analyzing the kinetics of degradation of Acid Red B dye through Fenton oxidation with online monitoring system

2021 ◽  
Vol 216 ◽  
pp. 412-422
Author(s):  
Aiguo Li ◽  
Xiaofeng Fang ◽  
Jiangyuan Sun ◽  
Qianpeng Liu ◽  
Yingying Lian ◽  
...  
Keyword(s):  
Monitoring System ◽  
Online Monitoring ◽  
Fenton Oxidation ◽  
Kinetics Of Degradation ◽  
Online Monitoring System ◽  
Kinetics Of

The Interactions of Soil-Borne Microorganisms and DCPA

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 470-473 ◽  
Author(s):  
B. G. Tweedy ◽  
Nikki Turner ◽  
Miriam Achituv
Keyword(s):  
Adverse Effect ◽  
New York ◽  
Carbon Source ◽  
Microbial Growth ◽  
Bacterial Population ◽  
Degradation Products ◽  
Past History ◽  
Subsequent Treatment ◽  
Soil Samples ◽  
History Of

Soil samples with and without a past history of dimethyl-2,3,5,6-tetrachloroterephthalate (DCPA) treatment were obtained from New York. A third sample was obtained from a field in Colorado where DCPA had been ineffective as a herbicide. The populations of bacteria and actinomycetes in these soils were determined and the actinomycetes were more prevalent in the samples with previous DCPA treatment than in untreated samples. Subsequent treatment resulted in an increase in actinomycete population and little change in bacterial population. In pure culture and in soils, the addition of DCPA had no adverse effect upon microbial growth, and several microorganisms appeared to utilize the herbicide as a carbon source. Two degradation products were methyl-2,3,5,6-tetrachloroterephthalate and 2,3,5,6-tetrachloroterethalic acid.

scholarly journals Desorption and re-adsorption of PAHS on aircraft soot surface

2020 ◽  
Vol 42 (4) ◽  
Author(s):  
Nguyen Mai Lan
Keyword(s):  
High Performance ◽  
Flow Reactor ◽  
Activation Energies ◽  
Binding Energies ◽  
Desorption Kinetics ◽  
Chemical Transformations ◽  
Polycyclic Aromatic ◽  
Kinetics Of Degradation ◽  
Kinetics Of ◽  
Pyrex Tube

Polycyclic Aromatic Hydrocarbons (PAHs) in aircraft soot are capable to distribute in the gas phase and particulate phase in chemical transformations in the atmosphere. The desorption of PAHs from the soot surface is a preliminary step in the study of the reactivity of particulate PAHs. The desorption kinetics of PAHs are measured from soot samples to determine desorption rate constants for different PAHs as a function of temperature and the binding energies between PAHs and soot. The kinetics of degradation of particulate PAHs were studied in the flow reactor. The soot samples previously deposited on a Pyrex tube are introduced into the reactor along its axis and the concentrations of PAHs adsorbed on soot are determined by the High-Performance Liquid Chromatography (HPLC) as a function of the desorption time. The results show a correlation between the size of PAHs and the thermodynamics of desorption: with the PAHs have the same number of carbon atoms, their energies of desorption are very similar and increase with this number. The activation energies EA and the number of carbon atoms in PAHs have a linear correlation. It is consistent with the additivity of the laws Van der Waals. The similarity between the activation energies of desorption of PAHs and the corresponding sublimation enthalpies is consistent with the similarity between the graphitic structure of soot and the structure of PAHs.

scholarly journals Supported TiO2 on Borosilicate Glass Plates for Efficient Photocatalytic Degradation of Fenamiphos

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
A. El Yadini ◽  
H. Saufi ◽  
P. S. M. Dunlop ◽  
J. Anthony Byrne ◽  
M. El Azzouzi ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Borosilicate Glass ◽  
High Performance ◽  
Order Kinetic ◽  
Degussa P25 ◽  
Plausible Mechanism ◽  
Kinetics Of Degradation ◽  
Glass Plates ◽  
Kinetics Of ◽  
Sulfonamide Group

Supported titanium dioxide (TiO2) was investigated for the photodegradation of the insecticide fenamiphos in water. The photocatalyst was immobilised on borosilicate glass plates and the kinetics of degradation were studied in a stirred tank reactor under UV irradiation. Two types of TiO2, for example, Millennium PC500 (100% anatase) and Degussa P25 (80% anatase, 20% rutile), were used. Their activities have been based on the rates of insecticide disappearance. Experiments were investigated to evaluate the effect of pH and initial concentrations of fenamiphos as well as catalyst doses on the photocatalytic degradation of fenamiphos. Kinetic parameters were experimentally determined and an apparent first-order kinetic was observed. For photolysis process of fenamiphos, two photoproducts were identified and characterized using high performance liquid chromatography/mass spectrometry (HPLC/MS). The plausible mechanism of photolysis involved is the oxidation of sulfonamide group. In presence of photocatalyst TiO2, photodegradation was observed. Under identical conditions, Degussa P25 shows higher photocatalytic activity in regard to PC500 Millennium and complete degradation was observed after 180 min.

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