M. Megharaj et al., EFFECTS OF PHENOLIC-COMPOUNDS ON GROWTH AND METABOLIC-ACTIVITIES OF CHLORELLA-VULGARIS AND SCENEDESMUS-BIJUGATUS ISOLATED FROM SOIL, Plant and soil, 140(1), 1992, pp. 25-34
Phenol and three nitrophenols (o-nitrophenol, m-nitrophenol, p-nitroph
enol), commonly occurring pollutants in natural eco-systems, were test
ed for their toxic effects on soil isolates of Chlorella vulgaris and
Scenedesmus bijugatus, growing under phototrophic, photoheterotrophic
and heterotrophic conditions. The toxicity criteria included cell numb
er, chlorophyll, total protein and carbohydrate content, (CO2)-C-14 up
take and in vivo nitrate reductase activity. Both C. vulgaris and S. b
ijugatus were sensitive to the pollutants when the cultures were grown
under phototrophic or heterotrophic conditions. However, the toxicity
was found reversed or alleviated upon photoheterotrophic growth of th
e cultures. Transmission electron microscope studies revealed various
cytological abnormalities in C. vulgaris in the presence of phenolics
at algistatic levels.