Growth and lipid content at low temperature of Arctic alga Chlamydomonas sp. KNM0029C

Abstract

Biodiesel produced from microalgae is a promising source of alternative energy. In winter, however, outdoor mass cultivation for biodiesel production is hampered by poor growth. Arctic Chlamydomonas sp. KNM0029C has an optimal growth temperature of 4°C, reaching densities up to 1.4 × 107 cells/mL. Lipid body formation was visualized by BODIPY 505/515 staining and fluorescence microscopy. The fatty acid methyl ester (FAME) production level of KNM0029C was 178.6 mg/L culture and 2.3-fold higher than that of C. reinhardtii CC-125 at 4°C. Analysis of the FAME content showed predominance of polyunsaturated fatty acids such as C16:3, C18:2, C18:3 and C20:2. C18:3 fatty acids comprised the maximum portion (20.7%), and the polyunsaturated fatty acids content (39.6%) was higher than that of saturated fatty acids (6.8%) at 4°C. Chlamydomonas sp. KNM0029C grows and produces fatty acids at low temperature and may represent a good source for biodiesel production in cold environments.