Published Paper Details:

Proliferous growth of green microalgae in sewage effluent can provide a cost-effective method for biofuel production. The aim of the present study was to investigate the efficiency of sewage effluent on the growth, biochemical changes and lipid accumulation capability of indigenous microalgae such as Monoraphidium contortum, Psueudomuriella sp. and Chlamydomonas sp. isolated from water bodies of Madurai, South India. Compared to other two selected algae, Chlamydomonas sp. exhibited greater growth rate (0.457 day-1 ) with high biomass density (0.74 mg/ml) during the exponential phase of growth (20th day). Profuse growth of Monoraphidium contortum and Psueudomuriella sp. were also observed in untreated wastewaters with a mean growth rate (?) of 0.439 and 0.277 day-1respectively. Carbohydrates, proteins, lipids and fatty acid contents were also affected signi?cantly by the effluent composition and growth stages of microalgae. Chlamydomonas sp achieved a maximum lipid content of 27.7% (w/w) followed by Monoraphidium contortum with 26% (w/w). Fourier transform infrared spectra showed clear transitions in biochemical composition with an increased lipid/protein ratio at the end of the culture. Gas chromatography indicated the presence of high content of palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2) adding to the biodiesel quality. Efficient nutrient uptake, profuse biomass and high lipid content (comprised of saturated fatty acids) make the Chlamydomonas sp. as the best microalgae and viable source for biofuel production in sewage effluent. The results also emphasized that the sewage effluent can serve as a cost effective medium for biofuel production and thereby preventing eutrophication.