Salicylate biodegradation by various algal-bacterial consortia under photosynthetic oxygenation

Four green microalgae (Chlorella sorokiniana, Chlorella vulgaris, Scenedesmus obliquus and Selenastrum capricornutum), a wild Bolivian microalga strain and two cyanobacteria (Anabaena catenula and Microcystis aeruginosa) were compared for tolerance to salicylate, O2 production capacity and ability to support salicylate degradation by a Ralstonia basilensis strain in symbiotic microcosms with the microalgae. Microcystis aeruginosa had the highest tolerance to salicylate at 500 mg l(-1) and 1500 mg l(-1) but only produced 0.7 mg O2 l(-1) h(-1) in the absence of pollutant. Chlorella sorokiniana resisted salicylate at 1500 mg l(-1) with the highest O2 production in the absence of salicylate (26 mg l(-1) h(-1)) closely followed by the Bolivian microalga (23 mg l(-1) h(-1)) and Chlorella vulgaris (21 mg l(-1) h(-1)). Selenastrum capricornutum and Anabaena catenula were completely inhibited by salicylate at 500 mg l(-1). When inoculated with Ralstonia sp. and supplied with salicylate, Chlorella sorokiniana had the highest removal rate (19 mg l(-1) h(-1)), followed by the wild Bolivian strain (18 mg l(-1) h(-1)) and Chlorella vulgaris (14 mg l(-1) h(-1)).