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Organic Chemicals : An Environmental Perspective - Chapter 6

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Đại học của phân hủy sinh học và chuyển dạng sinh học Tóm tắt Một cố gắng đã được thực hiện để mô tả những con đường được sử dụng bởi các vi sinh vật phân huỷ hay biến đổi xenobiotics. Hầu hết các nhóm cấu trúc chủ yếu được xem xét, bao gồm béo, thơm, alicyclic, và các hợp chất dị vòng, bao gồm cả những người có oxy, lưu huỳnh, Các chất nitơ, phốt pho, hoặc halogen. Mặc dù các hợp chất organochlorine đã nhận được sự chú ý nhất, một nỗ lực đã được thực hiện bao gồm. | Neilson Alasdair H. Pathways of Biodegradation and Biotransformation Organic Chemicals An Environmental Perspective Boca Raton CRC Press LLC 2000 6_ Pathways of Biodegradation and Biotransformation SYNOPSIS An attempt is made to describe the pathways used by microorganisms to degrade or transform xenobiotics. Most of the major structural groups are considered including aliphatic alicyclic aromatic and heterocyclic compounds including those with oxygen sulfur nitrogen phosphorus or halogen substituents. Although organochlorine compounds have received most attention an attempt has been made to include also organobromine compounds the degradation of organofluoro compounds is discussed separately since these compounds differ significantly even in their chemical properties from those of the other halogens. Reactions carried out by both aerobic and anaerobic bacteria and to a somewhat lesser extent by yeasts and fungi are considered although no details of the enzyme systems are given. Attention is directed to the pathways that are used by different organisms for the degradation of a given xenobiotic. Investigations using aerobic bacteria have almost invariably been exemplified from the results of experiments using pure cultures whereas for anaerobic bacteria this has been supplemented by results using mixed cultures or stable consortia. Some examples are given of the application of biotransformation reactions in biotechnology and of the environmental significance of the biotransformations of xenobiot-ics which may result in metabolites more toxic than their precursors. Finally an attempt has been made to classify the reactions involved in the degradation of xenobiotics on the basis of well-established chemical transformations and specific reference has been made to the appropriate sections in which these reactions are discussed in greater detail. Introduction It is desirable to explain both the motivation and the objectives of this