Preliminary evaluation of biomass and lipid production potential of Nannochloropsis sp. under optimal conditions with different wastewater samples for Exopolymeric substances (EPS) production

¹ Centre for Waste Management
² Centre of Excellence for Energy Research
³ Department of Biotechnology, School of Bio and Chemical Engineering Sathyabama Institute of Science and Technology, Chennai, 600 119, Tamil Nadu, India.

^* Corresponding author: dawnsudha@yahoo.com

Abstract

Wastewater is a source of toxic chemicals, heavy metals and various pathogenic microorganisms. Disposal of untreated wastes into the environment causes antibiotic resistance of organisms and various pollutions. An efficient method for treating wastewater, producing bioenergy and byproducts on a sustainable basis is to cultivate microalgae in wastewater. Microalgae has emerged as a desirable source for biofuel production because of high biomass and lipid productivity from wastewater sources. The main characteristics that make microalgae an exceptional source of renewable energy are their quick growing rate, effective carbon collecting technique. Extracellular Polymeric Substance (EPS) production is getting more attention as a result of high hydrocarbon biosynthesis. STP water from effluent plant, wastewater from biogas plant and wastewater from biodiesel production plant were collected from Centre for Waste Management. Reverse osmosis water was used as control. Analysis of wastewater sample showed that its parameters exceeded safer limits. The bioremediation potential of Nannochloropsis species was studied at different concentration of sample. Nannochloropsis species was grown under stress conditions over 25-day period for biomass production and characterization. Lipids extraction was determined by the Bligh and Dyer method. The maximum growth and lipid production by Nannochloropsis species was observed in biodiesel wastewater sample than sample of biogas wastewater. The maximum lipid yield was 0.06 g/l in 1:1 ratio of sample and media.