• KSBB Journal
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• v.11 no.5
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• pp.524-528
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• 1996

Bacterial degradation of 4-chloro-2-methylphenoxyacetic acid (MCPA) was studied in column reactors under conditions approximating a fluidized bed system, with granular activated carbon (GAC) as a support matrix. A mixed bacterial culture of MCPA-degrading bacteria was used as an inoculum to develop a biofilm on GAC. Initially, adsorption of MCPA by GAC and blofilm formation on GAC were examined. MCPA degradation was evaluated with a batch and continuous mode of operation of the GAC fixed-film column reactors. In the batch operations, complete degradation of MCPA was achieved during the incubation period. Partial degradation of MCPA occurred in the continuous operations and MCPA degradation was dependent on the feeding rate of MCPA solution.

• Journal of Applied Biological Chemistry
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• v.42 no.2
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• pp.57-61
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• 1999

Seven numerically dominant 2-methyl-4-chlorophenoxyacetic acid (MCPA)-degrading bacteria were isolated from agricultural soils. The isolates utilized the herbicide MCPA as a sole carbon source, producing significant biomass in MCPA mineral medium. They exhibited diverse herbicide degradation capabilities, but most of them grew very slowly in mineral medium containing herbicide. The chromosomal DNA patterns of the isolates obtained by polymerase chain reaction amplification of repetitive extragenic palindromic sequences were distinct from each other. One isolate, SH3, which was identified as Sphingomonas species by fatty acid methyl ester analysis, was able to degrade 5 different phenoxyacetic acid herbicides within 4 days. This strain contains two plasmids, and the smaller one has a crucial role in herbicide degradation. MCPA treated into agricultural soils without indigenous MCPA-degraders persisted for a long time, but the application of the isolate SH3 resulted in rapid decline of MCPA concentration in the soil.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.361-370
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• 2010

This study was carried out to establish the analytical method of MCPA residue in brown rice and rice straw by HPLC/UVD. When MCPA was extracted from sample under the pH 3.6 by adding acetone 200 mL and 1N-HCl 100 mL, the extraction efficiency was high by 87%. And purification efficiency was high by 83% when 5 mL of 1% methanol/acetonitrile was eluated by the florisil Sep-pak cartridge column. From spiking of $0.1{\mu}g\;mL^{-1}$ and $0.25{\mu}g\;mL^{-1}$ of MCPA to control sample, respectively, average recovery rate of MCPA in brown rice was 96.0% and 94.9% and that in rice straw was 92.5% and 88.2%, respectively. Precision of experiment was very high by relative standard deviation of 1.5% to 5.7%. In brown rice and rice straw treated with bentazone+MCPA (11+1.2%) of 30 kg and 60 kg per ha at 30 days after rice transplanting, respectively, maximum residue limit was under $0.05{\mu}g\;mL^{-1}$ of the recommended rate of Korean Food and Drug Administration. From the above results, the analytical procedure of MCPA in plants such as hydrolysis, saponification and derivatization were ommited, and retention time was faster and recovery rate was higher than the existed results of HPLC/UVD. Therefore, these results were greatly improved and seemed to be usefully applied for residue analysis of MCPA in plants.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.394-399
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• 1986

From the lysates of the 7 selected strains of Pseulomonas utilizing 2-methyl-4-chlorophenoxyactate as a sole source of carbon and energy, several MCPA plasmids, which encodes genes for the degradation of 2-methyl-4-chlorophenoxyacetate, were isolated, and measured their molecular weight as well as genetic characters such as resistance to antibiotics and degradative ability of other chlorinated herbicides. Transmissibility of the MCPA plasmids, pKU1, pKU15, and pKU17 was tested by conjugation or transformation and the restriction pattern of pKU15 for Pvu II, Hind III, EcoR I, Xho I, Bgl II, and Ava II was analyzed.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.124-129
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• 1986

Weeds emerging on winter wheat and barley field at early spring are troublesome, even with pre-emergence application of herbicides such as butachlor, tribunil, etc. Searching the proper post-applicating herbicides to control those weeds, three herbicides; ioxynil, bromoxynil and MCPA were evaluated with weeding efficacies in barley field. Tank mixture of bromoxynil and MCPA was the most excellent in weeding efficacy, especially in higher mixing rate at early April application to the broad-leaf weeds, among others.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1091-1094
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• 2009

In order to find the characteristics of selected powerful Pseudomoanas sp. KU171(pKU19) degrading MCPA, many physiological and genetic tests were accomplished. By the curing and transformation experiment, it was found that the genes of Pseudomonas sp.KU171(pKU19) for MCPA-degrading were located on a plasmid pKU19. Also the plasmid had degradative gens for 2,A-D, 3CB, and DCP. Molecular size of pKU19 was measured to be 31.2Kb.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.320-328
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• 2006

This study was conducted to evaluate the herbicidal efficacy of flucetosulfuron+pyrazosulfuron-ethyl against Eleocharis kuroguwai and Scirpus planiculmis and to investigate tank-mix of flucetosulfuron + pyrazosulfuron-ethyl with bentazone and 2,4-D to control sulfonylurea resistant Monochoria vaginalis and Scirpus juncoides. In controlling E. kuroguwai, flucetosulfuron + pyrazosulfuron-ethyl showed 75% control, lower than that (95%) of bentazone + MCPA, at 29 DAA (days after application), while at 60 DAA it showed 90%, greater than that of (78%) of bentazone + MCPA, with greater control than penoxsulam at all times. In case of Scirpus planiculmis control, flucetosulfuron + pyrazosulfuron-ethyl showed lower activity than bentazone + MCPA but greater than penoxsulam. Flucetosulfuron + pyrazosulfuron-ethyl showed consistently high activities against Echinochloa crus-galli and E. kuroguwai regardless of soil flooding condition, while penoxsulam and bentazone + cyhalofop showed significantly lower activity in 5 cm flooding condition than 0 cm flooding condition. Flucetosulfuron + pyrazosulfuron-ethyl did not control sulfonylurea resistant Monochoria vaginalis and Scirpus juncoides, while its tank-mix with bentazone or 2,4-D at 2/3 or 1/2-folds of their recommended rates, respectively, provided > 90% control.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.663-665
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• 2010

By the curing and transformation experiment, it was found thatthe genes of Pseudomonas sp.KU171(pKU19) for MCPA-degrading were located on a plasmid pKU19. Also the plasmid had degradative gens for 2,4-D, 3CB, and DCP. Molecular size of pKU19 was measured to be 31.2Kb. The restriction pattern were analyzed with Eco RI, BglII,XhoI, and the restriction map was generated.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.1
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• pp.45-51
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• 1980

The effects of propanil, MCPA; 2, 4 5-T and silvex on the numder of new root and tiller on Taichung Native 1, Caloro, PI 245717 and Bluebonnet 50 by root administration and foliar spray at 10 levels of concentration were investigated. Phenoxy herbicides changed the growth pottern in the way of increased number of tillers and new roots rather than plant height or root length. It was suggested that MCPA is only possible to increase tillering around applicable range. Silvex stimulated tillering at higher level than that required to stimulate new root formation. Varietal response on herbicides were different along with herbicide feeding part. There was trends that the higher nitrogen response varieties also have a greater response to stimulating effect of herbicide. Propanil had no effect on growth and no injury even about 20 times of higher concentration of phenoxy herbicide.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.73-80
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• 1998

Peroxidase has been isolated to apparent homogeneity from earthworm, Lumbricus rubellus, using ammonium sulfate fractionation, Sephacryl S-2000 gel filtration, CM-cellulose cation exchange chromatography and native-PAGE elution. Some of its enzymatic characteristics were examined. The optimum pH for gruaiacol oxidation of earthworm peroxidase was determined to be 6.0, and the $K_{m}$ values against guaiacol and $H_2O_2$ were 1.25 mM and 3.4mM, respectively. When various compounds were tested as the possible substrates of the enzyme, o-dianisidine was used as the substrate. However, earthworm peroxidase could not oxidize esculetin and ferulic acid as substrates, suggesting the different characteristics of the enzyme from plant peroxidases. The optimum pH for veratryl alcohol and $H_2O_2$ oxidation was determined to be 2.5 when lignin peroxidation activity was examined. The $K_{m}$ values for veratryl alcohol and $H_2O_2$ were 0.02 mM and 0.13 mM, respectively. Furthermore, the earthworm peroxidase could oxidize phenoxyherbicides such as 2,4-D, 2,4-DP and MCPA as substrates. The optimum pHs for 2,4-D, 2,4-DP and MCPA were determined to be 4.0, 2.0 and 2.0, respectively. The most available substrate was 2,4-DP, followed by MCPA and 2,4-D when their peroxidation activities were compared.