View 1 excerpt, cites background. Characterization of multiple chlorobenzoic acid-degrading organisms from pristine and contaminated systems: mineralization of 2,4-dichlorobenzoic acid. Highly Influenced. View 4 excerpts, cites results and background. Degradation of 2-chlorobenzoic and 2,5-dichlorobenzoic acids in pure culture byPseudomonas stutzeri. A strain ofPseudomonas stutzeri KS25 utilizing 2-chlorobenzoic and 2,5-dichlorobenzoic acids as the sole carbon and energy source was isolated from polychlorophenol-contaminated soil and sewage, … Expand.
Degradation of 2,5- and 3,4-dichlorobenzoic acids by bacterial species indigenous to rotten onion bulb and PCB-contaminated soil. Aerobic mineralization of chlorobenzoates by a natural polychlorinated biphenyl-degrading mixed bacterial culture. Co-metabolism of di- and trichlorobenzoates in a 2-chlorobenzoate-degrading bacterial culture: Effect of the position and number of halo-substituents. Influence of organic and inorganic growth supplements on the aerobic biodegradation of chlorobenzoic acids.
Metabolism of 2,5-dichlorobenzoic acid inPseudomonas stutzeri. Abstract4-Chroropyrocatechol is formed as a results of the oxidation of 2,5-dichlorobenzoate byPseudomonas stutzeri. Microbial degradation of chlorobenzoates CBAs : Biochemical aspects and ecological implications. Pande 1 and A. Received 17 Feb Accepted 10 Apr Abstract Simultaneous photosensitized dechlorination and decarboxylation of isomeric mono- and dichlorobenzoic acids have been studied in the presence of naphthoxide ion in alkaline medium.
This method is also capable of detectomg all regio isomer analog impurities. The method for identification of the process impurities regio isomers of 2,3-DCBA synthesized in our group according to the International Conference on Harmonization ICH guidelines 6—8 is also discussed. Reddy's Laboratories Hyderabad, India Figure 1. Merck HPLC-grade methanol gradient grade, analytical grade glacial acetic acid Merck, Darmstadt, Germany and analytical grade ammonium acetate Fluka were used as received.
Water purified by a Millipore system in-house was used for making the solutions. The mobile phase A contained a mixture of 0. The flow rate was 1. The injection volume was 10 mL, and methanol was used as diluent. The LC systems used for method development and method validation were a Waters binary pump, plus autosampler with a PDA detector and an Agilent Wilmington, DE system equipped with a PDA detector and variable wavelength detector.
Various mobile phase compositions, columns of different packing materials C18, C8 and phenyl and configurations 15 and 25 cm columns were attempted to obtain good peak shapes and to resolve the peaks of all regio isomers and its impurities in 2,3-DCBA in single run.
The composition of mobile phases A and B as described previously were found to be appropriate for the separation of all process impurities and its regio isomers. A gradient elution system was designed as described previously. Changes in the composition of the gradient program and the experimental conditions were chosen within the optimum region predicted by the gradient mode. Because of the late-eluting isomers, the buffer concentration was chosen according to separation of all isomers.
Gradient elution provides several advantages: 1 higher separation selectivity, 2 better peak shapes, 3 higher sensitivity, 4 shorter retention times and 5 mass compatibility; the detection limit for 2,3-DCBA isomers was largely enhanced by using the gradient elution.
The standard solution was used as the system suitability solution; the system suitability solution was determined from the principle peak of the standard solution. For purity estimation of 2,3-DCBA, a 2. The sensitivity towards isomers and impurities was thus increased; the response of each impurity was recorded. Weight percentage of each isomer present in the sample was calculated by area normalization method because all regio isomers share the same response of 2,3-DCBA, therefore, the responses of all regio isomers are as per pharmacopeia guidelines; i.
Hence, all isomers falls under the same range 0. Therefore, this wavelength was selected for analysis. System suitability solution was prepared as described previously. The system suitability test solution was injected and the chromatographic parameters, theoretical plates and UPS tailing factor for the principle peak of 2,3-DCBA were evaluated to prove system suitability 9. A good linear relationship between the sample concentration and the detector response peak area of 2,3-DCBA was obtained [the correlation coefficient r 2 was calculated ].
Standard addition and recovery experiments were conducted to determine accuracy of the method for the quantification of isomers in the 2,3-DCBA sample. To determine the robustness of the developed method, experimental conditions were purposely altered and theoretical plates and tailing factor for the principle 2,3-DCBA peak was evaluated. The flow rate of the mobile phase was 1. To study the effect of flow rate on the theoretical plates and USP tailing, it was changed by 0. The pH of the mobile phase was 2.
To study the effect of pH on the theoretical plates and USP tailing, it was changed by 0. To study the effect of column oven temperature on the theoretical plates and USP tailing, it was changed by 5. The prepared mobile phase was kept constant during the study period. Metabolism of the chlorinated substrates resulted in the stoichiometric release of chloride, and degradation proceeded by intradiol cleavage of the aromatic ring.
Growth of both strains on 2,5-DCBA induced pyrocatechase activities with catechol and chlorocatechols as substrates. In contrast to dichlorobenzoic acids, growth on 2-CBA, benzoic acid, mono- and dihydroxybenzoic acids induced a pyrocatechase activity against catechol only. This is a preview of subscription content, access via your institution.
Rent this article via DeepDyve. Baggi G Richerche sulla degradazione di acidi clorobenzoici. Ann Microbiol 71— Google Scholar. Doetsch RN Determinative methods of light microscopy. Dolfing J, Tiedje JM Growth yeild increase linked to reductive dechlorination in a defined 3-chlorobenzoate degrading methanogenic coculture.
Arch Microbiol — Dorn E, Knackmuss H-J a Chemical structure and biodegradability of halogenated aromatic compounds. Two catechol 1,2-dioxygenases from a 3-chlorobenzoate-grown Pseudomonad.
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