Metabolism environmental fate

Highly halogenated organic compounds such as polychlorinated biphenyls and perchloroethylene appear to be too highly oxidised and low in energy content to serve as sources of electrons and energy for microbial metabolism. Bacteria are more likely to use them as electron acceptors in cell-membrane-based respiration processes [154]. The environmental fate of halogenated polymers such as polyvinylchloride or Teflon may depend on the question of whether it will be appropriate to sustain de-halorespiration processes. 

The modified terrestrial-aquatic model ecosystem described here has been found to be a useful tool in studying the environmental fate of drugs and related residues present in animal excreta used as manure. The operation of the ecosystem is relatively simple and yet it allows one to study the complex metabolic transformations of a drug or related residues in its various components. Especially interesting is the study of the degradation of a compound in the soil in the presence of microorganisms found in the animal excreta. This information is important since it eventually determines whether a compound and/ or its metabolites will bioaccumulate in the various elements of the environment. 

Specific data requirements are based on use patterns and are listed In Section 158. For example. In Subdivision N Environmental Fate, use patterns fall Into the categories of terrestrial uses, aquatic and aquatic Impact uses. Terrestrial uses Include domestic outdoor, green house, non-crop, orchard crop, etc., and data required varies with the use site. Depending on the site of use, studies on degradation, metabolism, mobility, dissipation, and accumulation might be required. Ihe general guideline format is as follows ... 

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