Phenol, or hydroxybenzene, was first discovered in 1834 and used in the raw state as creosote to prevent the weathering of railway ties and ships' timber, as well as to reduce odors in decomposed sewage. Phenol is derived from coal tar distillation and is manufactured by synthetic processes such as oxidation of methylethylbenzene, oxidation of toluene and heating of monochlorobenzene with sodium hydroxide under high pressure. In terms of production volume, phenol ranks among the top 40 chemicals in the United States, with 4.77 billion pounds of phenol manufactured in 1998 (van Schie and Young, 2000). Phenol is an important industrial chemical, and is used in the production of polycarbonate resins, explosives, paints, inks, perfumes, wood preservatives (as pentachlorophenol), textiles, drugs, and as an antibacterial and anti-fungal agent. Phenol is also used in medicine as a topical anesthetic or antiseptic.
Phenol concentrations from natural sources are typically much lower than from anthropogenic activities. Any type of plant material, including leaves, shoots, roots, and flowers, can potentially leach phenolic compounds. Some of these compounds, such as 4-hydroxybenzoate, serve as chemo-attractants for soil microbes, as recognition signals for plant-microbe interactions, or as transcription signals for nodulation genes in Rhizobium (Kape et al., 1991). Natural phenols may also be found in marine plants and algae (Boyd and Carlucci, 1993), or be excreted in the feces and urine of animals whose intestines are inhabited by microorganisms that feed on aromatic amino acid precursors such as tyrosine (Smith and Macfarlane, 1997).
Was this article helpful?