Role in pesticide degradation

In conclusion, the flavoprotein systems isolated from the algae and the bacteria, have a good potential to play significant roles in pesticide degradation in aquatic environments. Such flavoprotein systems are active in degradation of xenobiotics both under aerobic and anaerobic conditions by promoting photochemical and reductive reactions. 

Abiotic mechanisms for degradation of herbicides in soil, discussion, 15 Abiotic transformation processes of pesticide dissipation in soil hydrolytic reactions, 5 role in pesticide degradation, 4-5... 

LC-MS plays an important role in the analysis of pesticides and related componnds, e.g., herbicides, insecticides, acaricides, as well as their degradation prodncts and metabolites. The analysis of pesticides is relevant for environmental studies, food safety, toxicology, and occupational health. Pesticides have to be analysed in environmental samples, such as different water compartments, soil, sediments, sludge, and animal tissue like fish, in food, especially fruit and vegetables, and in (human) body fluids and tissues. Many modem pesticides and related compounds are not amenable to GC-MS analysis, or only after derivatization. Therefore, LC-MS has been evaluated as an alternative. Various review papers on the analysis of pesticides and related compounds in various sample matrices were published [1-8]. 

LC-MS plays only a minor role in the identification of pesticide degradation products. Both GC-MS and LC-MS were applied in some studies on the degradation of OPP [31, 78, 114] and of alachlor [115]. 

The humus in well-decomposed organic soils also plays a role in the bioavailability and retention of minor elements, pesticides, and pesticide degradation products, but this role is currently not well understood. 

Since this early discovery there has been considerable appreciation for the role of the soil microbial community in pesticide transformations. In some cases the role of microorganisms has been stressed by comparison of degradation rates in natural and sterilized systems (32), while in others researchers have chosen to use isolation of pesticide-degrading microorganisms from soil sis evidence of microbial involvement (33). It has also been recognized that environmental conditions that influence microbial activity (temperature, moisture,...) affect the microbial degradation of pesticides in soil (34). The importance of microbial involvement is demonstrated by the many reviews of pesticide/microbe interactions that have appeared (35-41). 

One approach to restoration of herbicidal activity in problem soils has been the use of microbial/enzymatic inhibitors (20). Stauffer Chemical Company (now ICI Americas) has provided leadership for the agrochemical industry in this area and provided potential inhibitors to university scientists for validation. Kaufman et al. (21) had earlier suggested the use of inhibitors to improve the performance of herbicides with short residual lives in soils. Kaufman et al. (3) discussed the role of pesticides as inducers, substrates, and/or inhibitors of degradative enzymes in soil microorganisms and gave selected examples of specific pesticides as inducers and others as inhibitors of certain enzymes. They also considered the potential of "multiproblem" soils. 

What I hope to do in this paper is to give the reader a brief introduction to bacterial genetics and then to describe the research that has demonstrated the involvement of plasmids in carrying genes which encode enzymes that degrade pesticides. I will then discuss the possible role of plasmids in the development of the enhanced degradation phenomenon and the types of research that may lead to the delineation of the molecular events that lead to the development of rapid pesticide degradation in soils. 

The quality of food is very important for health. The presence of heavy metals plays a large role in establishing food quality, and occasionally the presence of pesticides in food decreases the food quality. Thus, knowing the toxicity of adjuvants and their degradation products is very important. 

Plant processes. In plants chemical substances enter, are transported, are absorbedinto organic matter andbioaccumulated, are metabolised and degraded. In agricultural areas, plant processes may therefore play a significant role in the fate of pesticides. 

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