Phytoremediation
Definition
Phytoremediation is a process that uses vascular plants as a means of extracting inorganic and organic contaminants from soils (1). The strategies used in phytoremediation can be grouped into physical, chemical and biological methods for mitigating the effect subsurface pollutants have on the soil and groundwater.
Strategies
Phytodegradation
Phytodegradation utilizes the metabolic capability of plants in breaking down soil contaminants. The term “green liver” has been used to describe this process as the plant metabolizes xenobiotic compounds in an analogous way to that of the mammalian liver (2). In plants, the xenobiotic metabolism occurs over three phases; transformation, conjugation, and excretion.
Phase 1: Transformation
The first phase involves the chemical modification of the xenobiotic compound by either oxidation, reduction, or hydrolysis. This causes the xenobiotic to become more water soluble and thus be more biochemically reactive within the plant (3). Plants utilize many different enzymes to alter these compounds. Cytochrome P450 family enzymes act as mono-oxygenases towards a broad range of substrates and convert hydrophobic compounds into those which are more soluble in water (4). Carboxylesterases (CXEs) can convert carboxyl esters into carboxylic acids via hydrolysis which can go on to react with other molecules in the next phase (5).
References
- Reichenauer, Thomas G., and James J. Germida. “Phytoremediation of Organic Contaminants in Soil and Groundwater.” ChemSusChem, vol. 1, no. 8‐9, WILEY‐VCH Verlag, 2008, pp. 708–17, doi:10.1002/cssc.200800125. https://chemistry-europe-onlinelibrary-wiley-com.gate.lib.buffalo.edu/doi/full/10.1002/cssc.200800125#bib23.