Modélisation de la croissance de Scenedesmus ecornis. Interaction de la lumière et de la température

Light and temperature interactions on growth of the green alga Scenedesmus ecornis were studied in batch cultures and under non-limited nutrient conditions. For each temperature tested, the relationship between growth rate and light intensity was fitted with three mathematical models (STEELE 1965, PLAIT & JASSBY 1976, PEETERS & EILERS 1978). Among those, the PEETERS & EILERS'S function gives the better ajustment. Maximum growth rates (μmax T ) and optimal light intensities (lopt T ) in relation to temperature were well described by the model of LEHMANN et al. (1975). The positive correlation (r = 0.97) between μmax T and lopt T demonstrates a close interaction between light and temperature effect on the alga growth rate. A maximum growth rate of 2.1 per day is observed at a temperaure of 30 °C and a light intensity of 400 μE m -2 s -1 . All the results make it possible to envisage the outdoor mass culture of this species with an interesting productivity.