Study on autotrophic and mixotrophic cultivation conditions of Chlorella vulgaris microalgae for biodiesel production

Oil extracted from microalgae, is a potential energy source, as it can be easily converted to fatty acid methyl ester or hydrocarbon type biodiesel. The aim of the present work was to optimize the production of biodiesel by Chlorella vulgaris in mixotrophic and autotrophic cultivated conditions. Comparison of cell growth rate of Chlorella vulgaris was carried out, in TMRL(AG) and TX batch culture media, in four treatments and three repeats for ten days. In each treatment, Chlorella vulgaris was counted every two days once. Based on the results of this survey, the highest cell growth, 118×106 cell/ml, was recorded in autotrophic condition in TMRL(AG) medium and lowest count number was 77× 106 cells/ml in TX medium, in mixotrophic condition. There was significant difference between different media and average density of microalgae Chlorella vulgaris cell growth in ten days (p≤0.05). In this study, growth rate and growth coefficient showed more rapid growth of Chlorella in TMRL medium compared with TX medium. Oil content in TMRL (AG) media in mixotrophic and autotrophic cultivation conditions were %4.22 and %1.21, respectively. Our results revealed, for large scale culture of microalgae Chlorella, in order to be used in industrial biodiesel production, TMRL(AG) medium showed higher cell growth rate, greater amount of oil production and lower overall cost, in mixotrophic condition.