Intradiol Dioxygenases — The Key Enzymes in Xenobiotics Degradation

Abstract

Aromatic compounds are derived from both natural and anthropogenic sources. Under natural conditions, arenes are formed as a result of the pyrolysis of organic materials at high temperatures during forest, steppe and peatland fires, and during volcanic eruptions. Biogenic aromatic compounds like aromatic amino acids and lignin, the second most abundant organic compound in the environment, are universally distributed in nature. Many species of plants, especially willow (Salix), thyme (Thymus vulgaris), camomile (Chamomilla recutita), bean (Phaesoli vulgaris) or strawberry (Fregaria ananasa), water plants as sweet flag (Acorus calamus) and many species of alga are known to produce aromatic compounds as secondary metabolites [1-4]. A lot of aromatic compounds are introduced to the environment as contaminating compounds from chemical, pharmaceutical, explosive, dyes, and agrochemicals industry. Chloro-, amino- and nitroaromatic derivatives, biphenyls, polycyclic aromatic hydrocarbons accumulate in the soil and water. They are toxic to living systems including humans, animals, and plants. Moreover, most of them may bioaccumulate in the food chain and have mutagenic or carcinogenic activity [5-8].