tailieunhanh - Lipid Accumulation Studies In Chlorella Pyrenoidosa Using Customized Photobioreactor - Effect of Nitrogen Source, Light Intensity and Mode of Operation

Lipid productivity of Chlorella pyrenoidosa was studied in a customized laboratory scale photobioreactor. Lipid yield increased when C. pyrenoidosa was subjected to stress conditions like different nitrogen sources, light intensities and modes of cultivation. It was observed that the growth rate of C. pyrenoidosa was directly proportional to light intensity and nitrogen concentrations. | Rajasri Yadavalli, Ramgopal Rao S, C. S. Rao / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 2, Issue 3, May-Jun 2012, Lipid Accumulation Studies In Chlorella Pyrenoidosa Using Customized Photobioreactor- Effect of Nitrogen Source, Light Intensity and Mode of Operation Rajasri Yadavalli*, Ramgopal Rao S and C. S. Rao Department of Biotechnology, Sreenidhi Institute of Science and Technology, Hyderabad-501301, Andhra Pradesh, India. ABSTRACT Lipid productivity of Chlorella pyrenoidosa was studied in a customized laboratory scale photobioreactor. Lipid yield increased when C. pyrenoidosa was subjected to stress conditions like different nitrogen sources, light intensities and modes of cultivation. It was observed that the growth rate of C. pyrenoidosa was directly proportional to light intensity and nitrogen concentrations. Of the two nitrogen sources tested, sodium nitrate proved better than urea in terms of lipid yield. The study also demonstrated that at lower nitrogen concentrations fed batch mode of cultivation resulted in maximum lipid productivity of g/ at 135 µmol m-2s-1 when compared to batch mode. Keywords: Modes of cultivation, Light intensities, Biomass, Lipid productivities, C. pyrenoidosa Photobioreactor 1. INTRODUCTION Rapid depletion of fossil fuels poses a major challenge to mankind. The ever growing concerns on climate change and global warming necessitates the need for renewable and carbon neutral transport fuels for both ecological and economical sustainability. Alternate energy resources like biodiesel are commercially produced currently from plant and animal oils, but not from microalgae which are photosynthetic and ever-present in any aquatic ecosystem. Microalgae are sunlight-driven cellular factories that are easy to culture and require less space for cultivation [1]. They convert carbon dioxide to potential biofuels, valuable bioactive compounds such as .