Biochemical composition of the green algae Scenedesmus abundans: effects of culture conditions

To evaluate aspects of enhancement of the green algae Scenedesmus abundans (Chlorophyceae), its biochemical composition was examined in cultures expos ed to different environmental conditions. Amongst the factors studied, temp erature has the greatest effect. Protein content is maximal at 15 degrees C , while lipid and carbohydrate contents were maximal at 25 degrees C and 35 degrees C respectively. Light intensity has no effect on protein and carbo hydrate content, but the lipid component decreases by approximately 20% at a light intensity of 300 mu mol quanta.m(-2).s(-1). Moreover the nitrogen s ource has no significant effect on the cellular content of these three comp ounds. An increase in nitrogen concentration induces an increase in protein and lipid content with, however, a reduction in biomass production above c oncentrations of 400 mg l(-1) KNO3. Modifications of the biochemical compos ition of Scenedesmus abundans as a function of the growth phase have also b een observed. In the stationary growth phase, these modifications can be su mmarised as a marked reduction in protein content and, to a lesser extent, in lipid content, accompanied by a considerable accumulation of carbohydrat es. The results are analysed taking into account the production yield of ea ch of the three types of compound.