GENERAL KNOWLEDGE

Detailed explanation-1: -The biodegradability of xenobiotics can be characterized by biodegradability tests such as: rate of CO2 formation (mineralization rate), rate of oxygen consumption (respirometry test), ratio of BOD to COD (oxygen used for biological or chemical oxidation), and by the spectrum of intermediate products of biodegradation.

Detailed explanation-2: -Bacteria, which are used for bioremediation of xenobiotics includes aerobic, anaerobic, Methanotrophic, Methanogenic bacteria, Cyanobacteria and Sphingomonads. Pseudomonas species has been used for the degradation of several xenobiotic compounds.

Detailed explanation-3: -Xenobiotic is a term used to describe chemical substances that are foreign to animal life and thus includes such examples as plant constituents, drugs, pesticides, cosmetics, flavorings, fragrances, food additives, industrial chemicals and environmental pollutants.

Detailed explanation-4: -Biodegradation of such compounds involves two distinct steps: • (i) Elimination of the halogen groups, and • (ii) Degradation of the non-halogenated product molecule. substitution of halogen by-H, -OH or a-thio group. The direct halogen removal produces a double bond and is relatively rate in nature.

Detailed explanation-5: -Factors Affecting Biodegradation: Several factors influence biodegradation. These include the chemical nature of the xenobiotic, the capability of the individual microorganism, nutrient and O2 supply, temperature, pH and redox potential.