ABSTRACT
Heterotrophic microbes have the most diverse catabolic metabolism of all organisms, and microbes have been found with the capacity to mineralize many of the organic xenobiotics that humans release into the environment. In many animals the liver detoxifies reactive organic species, including organic xenobiotics such as pharmaceuticals, and releases the products, primarily in conjugated form, into excretion systems. Plant production of and responses to toxic organic allelochemicals are therefore of major ecological and agricultural interest. The extremely wide range of organic xenobiotics can be categorized by their environmental fate, their use, their origin, or their physico-chemical properties. In general, non-polar organic toxins that pass quickly through membranes can be carried in the transpiration stream, and leak out of it relatively slowly because xylem has lignified cell walls. The many organic toxins are polar or that can ionize adsorb to particles in significant quantities, especially to soil organic matter and charged minerals.
