Natural degradation ways of herbicides of sulfonylurea group

Currently in agriculture much attention is paid to development and use of low-cost and at the same time effective methods of fight against weeds. In this regard, widely purchased sulfonylurea herbicides. The paper presents the general characteristics, mechanism of action, degradation pathways (hydrolysis, photochemical transformation and microbial degradation) of metsulfuron-methyl and tribenuronmethyl. The key role of chromato-mass-spectrometry to establish the mechanisms of destruction these herbicides by soil microorganisms is shown

The natural ways of degradation of pesticides based on 2,4-dichlorophenoxyacetic acid

To increase crop yields by destroying weeds the separate group of pesticides exist, that is called herbicides. Among the herbicides based on chlorphen oxalcanecarboxylic acids products of sodium and ammonium salts, as well as 2,4-dichlorophenoxyacetic acid (2,4-D), are widely used. However, the production and use of pesticides affects the state of the environment and pose a potential risk for public health. In this paper the need to clarify the mechanisms of transformation and degradation of 2,4-D de-rivatives under the action of physical, chemical and biological environmental factors was showed. The preparations based on 2,4-D, registered in the Republic of Belarus is reviewed. The mechanisms of action of these xenobiotics are described, analysis of their toxicity for the environment components is performed. Particular attention is paid to the microbial degradation of pesticides, possible ways of their degradation under the action of microorganisms enzyme systems are described, the factors, that affect the biotransformation process are an alyzed. It has been shown that th e bacterial degradation of 2,4-D is carried with the formati on of 2,4-dichlorophenol by en zyme 2,4-dihlorphenoxyacetate-α-ketog-lutaratedioxygenase, and further the intermediate degrades with 3,5-dihlorocatechol formation using 2,4-dihlorphenolhydroxylase in two ways: or tho-splitting or peripheral meta-splitting