Degradation of phenols by algae

Abstract

Strains of Chlorella sp., Scenedesmus obliquus and Spirulina maxima were tested for degradation of some phenolic compounds listed by U.S. EPA as priority pollutants. Toxins were dissolved in a medium (pH 7 -7.2) without carbon source (except for testing Spirulina, in which case sodium bicarbonate was part of the medium at pH 9 -9.2) and algae prepared by batch cultivation were added. Phenol was found to be degraded easily by all tested algae at a concentration about 1000 mg 1 -1 . 2,4-dimethylphenol was found to be converted by Chlorella (even at a concentration of about 1000 mg1 -1 ) to an isomer of dimethylbenzenediol that was in some cases accumulated in the medium. Depending upon biomass and toxin concentration the rate of degradation changed and an optimum of toxin concentration which induces degradation might exist. Complete degradation could be reached with biomass concentrations higher than 4 g 1 -1 . 2,4-dinitrophenol at a concentration of about 190 mg 1 -1 was degraded by Scenedesmus quickly after an adaptation period of 5 days. 2-chlorophenol at a concentration about 200 mg 1 -1 was degraded and partly dechlorinated by Chlorella. Biodegradation of 2,4-dichlorophenol was not proven but the condition under which algae can survive a higher concentration of toxin could be found. All algae tested have a mechanism for degradation of phenolic compounds.

Removal of p-chlorophenol by the marine microalga Tetraselmis marina

“…Á consortium of Coenochloris pyrenoidosa and Chlorella vulgaris was found to biodegrade p-CP (Lima et al 2004) while o-CP degradation by Chlorella sp. was reported by Klekner and Kosaric (1992). In another study, an unidentified freshwater microalga isolated from pentachlorophenol treated water degraded pentachlorophenol (Tikoo et al 1997).…”

“…Few biodegradation studies on chlorophenolic compounds with microalgae have been described, most of them referring to freshwater environments (Klekner and Kosaric 1992;Tikoo et al 1997;Hirooka et al 2003;Lima et al 2004). The existing reports on chlorophenol biodegradation by marine microalgae refer only to marine diatoms (Yang et al 2002;Lovell et al 2002).…”

Biodegradation of phenol by a novel diatom BD1IITG-kinetics and biochemical studies

“…Algal phenol degradation capability is much less studied as compared to bacterial and fungal strains. Phenol biodegradation ability has been reported by strains of Chlorella sp., Scenedesmus obliqus and Spirulina maxima (Kelknar and Kosarnic 1992), Ochromonas danica (Semple and Cain 1996), Ankistrodesmus braunii and Scenedesmus quadricauda (Pinto et al 2003), Chlorella vulgaris (Scragg 2006;El-Sheekh et al 2012), Chlorella VT-1 (Scragg 2006), Volvox aureus, Lyngba lagerlerimi, Nostoc linkia, Oscillatoria rubescens (El-Sheekh et al 2012). Reports are available only on phenol degradation ability by microalgae with no further details of kinetics and enzymatic pathway of phenol metabolism.…”

Increase in biodegradation of dimethyl phthalate by Closterium lunula using inorganic carbon

“…It was reported that more than 30 azo compounds were biodegraded and decolorized by Chlorella pyrenoidosa, Chlorella vulgaris and Oscillateria tenuis, in which azo dyes were decomposed into simpler aromatic amine (Liu and Liu, 1992). Klekner and Kosaric (1992) found that 2,4-dinitrophenol was quickly biodegraded and converted to an isomer of dimethyl benzenediol by Chlorella. In the study of biodegradation of phenol by Ochromonas danica, it was found that [U-14 C] phenol could be completely mineralized (Semple and Cain, 1996;Semple, 1998).…”