Fate of substituted benzoates in the freshwater green alga, Chlamydomonas reinhardtii 11-32b

The removal of chlorinated, nitrated, and sulfonated benzoic acids in cultu res of the unicellular green alga, Chlamydomonas reinhardtii 11-32b, was in vestigated, and the metabolic fate of a model compound, 4-chloro-3,5,-dinit robenzoic acid, was determined. The freshwater alga was able to remove a wi de variety of benzoic compounds from the incubation medium. Chlamydomonas d iscriminated very specifically between the benzoic acids, indicated by the varying degrees of which the test compounds disappeared from the culture me dium. Moreover, the alga was capable of transforming 4-chloro-3,5-dinitrobe nzoic acid to several metabolites. A release of chloride ions was ob served , and 3,5-dinitro-4-hydroxybenzoic acid was identified as a major transient pro duct in the algal metabolism of 4-chloro-3,5-dinitrobenzoic acid.