GROWTH RATE, PIGMENT COMPOSITION AND FATTY ACID PROFILE OF Chlorella pyrenoidosa
Chlorella pyrenoidosa isolated from the water bodies of Madurai was maintained in Chu10 medium with a photoperiod of 12 hours light/ 12 hours dark, light intensity of 2000 lux at a temperature of 250C. Growth rate, pH, dry weight and pigments such as chlorophyll a, carotenoids were monitored at an interval of 10 days until the 50th day of growth. The amount of chlorophyll a and carotenoids was maximum on 40th day of growth. Nile red fluorescence indicated more number of lipid bodies on 40th day. At 460-480nm excitation light, the nile red fluorescence of lipid vesicles exhibited an emission maximum of 465nm and a quantum yield of 0.65. Lipid content (48.8% dry weight) was maximum on 40th day of growth. HPTLC analysis of lipids showed the presence of glycolipid, digalactosyl diglyceride, phosphatidylcholine, phosphatidyl ethanolamine, monogalactosyl diglyceride. Fatty acid analysis by GC indicated more amount of saturated fatty acids in C. pyrenoidosa. Hydrocarbon analysis by GC-MS was done using the hexane extract of the algal strain. Linear regression analysis showed a significant relationship between OD and dry weight, OD and pigments, dry weight and lipid weight.