Xenobiotic compounds biodegradation

Xenobiotic Compound foreign to biological systems. Often refers to human-made compounds that are resistant or recalcitrant to biodegradation and decomposition. 

Aelion CM, CM Swindoll, FK Pfaender (1987) Adaptation to and biodegradation of xenobiotic compounds by microbial communities from a pristine aquifer. Appl Environ Microbiol 53 2212-2217. 

Aelion CM, DC Dobbins, FK Pfaender (1989) Adaptation of aquifer microbial communities to the biodegradation of xenobiotic compounds influence of substrate concentration and preexposure. Environ Toxicol Chem 8 75-86. 

Ethylene dibromide (EDB, also 1,2-dibromoethane) is a xenobiotic compound used as a gasoline additive and a soil fumigant. What initial biodegradation product would you expect from this compound ... 

Now we can see the types of biochemical factors that determine the rate constant, fcbio for Michaelis-Menten cases the ability of the enzyme to catalyze the transformation as reflected by the quotient, kE/KiMM, and the presence of enzyme in the microorganism population involved, as quantified by [Enz]tot/[B], In the following section, we develop some detailed kinetic expressions for one case of enzyme-mediated transformations. Examination of these results will help us to see how structural features of xenobiotic compounds may affect rates. Finally, we will improve our ability to understand the relative rates for structurally related chemicals that are transformed by the same mechanism and are limited at the same biodegradation step. 

To a large extent, xenobiotic compounds in the aquatic environment are bound with sediments and suspended solid materials, such as humic acids. This binding plays a large role in biodegradation. Indeed, the structure of the bound form of the xenobiotic, such as a humic acid complex with a synthetic organic compound, may largely determine its rate of enzymatic degradation. 

Kuiper J, HanstveitAO. 1988. Biodegradation rates of xenobiotic compounds in plankton communities. In Capuzzo JM, Kester DR, eds. Oceanic processes in marine/communities. Vol 1 Biological processes and wastes in the ocean. Malabar, FL Robert E. Kroeger Publishing Co., 79-88. 

Enzyme-based applications for environmental screening or monitoring demand tailored biocatalysts performing catalysis in non-natural substrates and/or in non-usual or hostile media. Moreover, the increased complexity of contaminated environmental sites also demands efiicient biodegradation of xenobiotic compounds through new and multiple engineered pathways where the tailored biocatalysts should perform in their host microbial cells [434]. 

Cook AM, R Hiitter (1981) Degradation of 5-triazines a critical view of biodegradation. In Microbial Degradation of Xenobiotics and Recalcitrant Compounds (Eds T Leisinger, AM Cook, R Hiitter, J Niiesch), pp. 237-249. Academic Press, London. 

Inherent biodegradability is applied when the compound may be degraded, though not under the standard conditions generally used their degradation may require, for example, preexposure to the xenobiotic. 

These procedures may clearly result in the dominance of organisms that carry out only biotransformation of the xenobiotic, although the biodegradation of many of these compounds has also been demonstrated using the same or other organisms. 

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