1.2.4- triazine degradation

Kitts CL, DP Cunningham, PJ Unkefer (1994) Isolation of three hexahydro-l,3,5-trinitro-l,3,5-triazine-degrading species of the family Enterobacteriaceae from nitramine explosive-contaminated soil. Appl Environ Microbiol 60 4608-4711. 

Karns JS, RW Eaton (1997) Genes encoding i-triazine degradation are plasmid-borne in Klebsiella pneumoniae strain 99. J Agric Food Chem 45 1017-1022. 

Seth-Smith HMB, SJ Rosser, A Basran, ER Travis, ER Dabbs, S Nicklin, NC Bruce (2002) Cloning, sequencing, and characterization of the hexahydro-l,3,5-trinitro-l,3,5-triazine degradation gene cluster from Rhodococcus rhodochrous. Appl Environ Microbiol 68 4764-4771. 

Oxygen deficiencies under field conditions have been reported to retard. v-triazine degradation. For example, Ro and Chung (1995) reported that in wetland sediments amended with nutrients, lOppm of atrazine reduced to less than lOppb within 3 weeks under aerobic conditions. Under anaerobic conditions, less than 50% degradation was reported in 38 weeks. However, Kruger et al. (1996) reported an opposite observation for a saturated soil where a 4-fold increase in degradation was reported. 

Eaton, R.W. and J.S. Karns (1991b). Cloning and comparison of the DNA encoding ammelide aminohydrolase and cyanuric acid amido-hydrolase from three s-triazine-degrading bacterial strains. J. Bacteriol., 173 1363-1366. 

Karns, J.S. and R.W. Eaton (1997). Genes encoding s-triazine degradation are plasmid-bome in Klebsiella pneumonia strain 99. J. Agric. Food Chem., 45 1017-1022. 

Radosevich, M., S.J. Traina, and O.H. Tuovinen (1997). Atrazine mineralization in laboratory-aged soil microcosms inoculated with s-triazine-degrading bacteria. J. Environ. Qual., 26 206-214. 

Triazine biodegradation in soil is dependent on a number of factors, most importantly the presence, population, and activity of triazine-degrading microorganisms. Therefore, factors that affect soil microbial populations and activity... 

This section discusses the occurrence of the degradation products of atrazine, cyanazine, simazine, propazine, prom-etryn, and prometon, as well as their degradation pathways from soil into surface water. More detailed discussion of triazine degradation can be found in several other chapters of this book. 

Chemistry and Transport of Triazine Degradation Products in Water 469... 

A study was designed to define the relative rates of dealkylation of selected triazine herbicides and two monodealkylated triazine degradation products in the unsaturated zone and in surface runoff. Atrazine and propazine degrade to DEA by deethylation and deisopropylation, respectively. Similarly, atrazine and simazine can both dealkylate to DIA by removal of an isopropyl and ethyl side chain, respectively (Figure 30.12). Differences in the concentration of the dealkylated degradation product from the two different sources should indicate any preferential removal of ethyl versus isopropyl side chain. Furthermore, because monodealkylated DEA and DIA have different side chains remaining, their relative rate of removal should provide additional information on the liability of the ethyl side chain versus an isopropyl side chain. 

Seth-Smith, H.M.B., S.J. Rosser, A. Basran, E.R. Travis, E.R. Dabbs, S. Nicklin et al. (2002). Cloning, sequencing and characterisation of the hexahydro-1,3,5-trinitro-1,3,5-triazine degradation gene cluster from Rhodococcus rhodochrous. Appl. Env. Microbiol. 68, 4764—4771. 

The analysis of highly polar molecules in water samples at the trace level is often limited by the efficiency of the extraction procedures. Due to their high solubility in water, these molecules are frequently not sufficiently retained in the stationary phases of the chromatographic or solid-phase extraction supports. Immunochemical techniques present an advantage to allow direct measurements in aqueous media. Therefore, it is necessary to develop screening methods to efficiently monitor contamination by these triazine degradation products. 

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