Effects of Some Nutritional Factors on the Growth of Chlorella vulgaris in a Mixotrophic Cultivation

The microalgae Chlorella vulgaris is not only known as a source of lipid compounds for the biofuel industry but also as a potential source of biomass production for aquaculture. This study investigated the influence of some nutritional factors (organic carbon source and C:N ratio) on the growth rate of Chlorella vulgaris. Glucose, sodium acetate, and sucrose were used to check the effect of the carbon sources. Meanwhile, five different ratios of C:N (1:1, 6:1, 12:1, 18:1, and 24:1) were tested. Results showed that glucose was the most suitable source of organic carbon for the biomass development of the Chlorella vulgaris; the ratio C:N=18:1 equivalent to 52.92 mmol/L carbon and 2.94 mmol/L nitrogen is the most appropriate ratio to promote biomass increase. The maximum growth rate of C. vulgaris recorded in this study was 0.58±0.03 day-1 in treatment supplemented with glucose at ratio C:N=18:1.