ISOLATION, IDENTIFICATION AND CHARACTERIZATION OF POTENTIAL MICROALGAE FROM DTU LAKE AND ITS EVALUATION FOR BIOFUEL PRODUCTION

Abstract

Due to the increasing demand of energy by leaps and bounds, it is requisite to identify the local solution for the generation of energy to mitigate the future demand. Microalgae have been conferred as a potential source of biomass based energy. Many potential microalgae have been isolated for biofuel production across the globe till date considering their enormous potential and compatibility to be converted into liquid and gaseous fuels. Herewith, we have focussed on the isolation and characterization of a potential microalgae strain from the local water bodies under natural environmental conditions which provides an edge to commercialization of microalgae biofuel production. Microalgae sample obtained from Delhi Technological University’s lake (DTU Lake) was used for the isolation of potential microalgae. Light microscope, Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and 28S rDNA analysis were performed for identification of microalgae. After the identification, effect of various abiotic factors such as light (intensity, color and period), pH of medium, shaking period and temperature on algal growth rate and biomass productivity was studied. Scenedesmus rubescens provided maximum biomass productivity in white light of 36W intensity under illumination of 16 hours. pH 8, 24 hours shaking period and 26±2⁰C temperature were also found to be best for this microalga. The present study also aims to find out the superior source of nitrogen, phosphorous and carbon for the optimum growth rate and biomass productivity (dry cell weight) for freshwater microalgae Scenedesmus rubescens. Seven different freshwater media compositions were also tested for a period of 27 days. Among Nitrogen Sources (NH4Cl, CO(NH₂)₂, NaNO3, KNO3, Co(NO3)2 and Ca(NO3)2 ) Urea followed by Sodium Nitrate was found to be the best source. For Phosphorous Source, K2HPO4 showed the optimum yield as compared to NH4H2PO4, KH2PO4 and Na2HPO4. Sucrose was found to be the superior carbon source than Glucose, Sodium Acetate and Glycerol for the optimum growth and biomass yield. Modified HUT medium was found to be best media for the microalga Scenedesmus rubescens. Lipid and chlorophyll content was also determined.