Uranium adsorption and oil emulsification by extracellular polysaccharide (EPS) of a halophilic unicellular marine cyanobacterium Synechococcus elongatus BDU130911
Vijayaragavan Rashmi, Darshana Arulraj, Bhuvaneshwari Thangaraj, Sushanta Kumar Saha, Lakshmanan Uma, Dharmar Prabaharan
Abstract
An integrated approach on uranium adsorption and emulsification of oils was evaluated using extracellular polysaccharides (EPS) of a marine unicellular cyanobacterium Synechococcus elongatus BDU130911. EPS gel of S. elongatus BDU130911 was able to adsorb uranium at the rate of 75% per gram dry weight. Uranium follows a monolayer adsorption onto EPS gel surface as revealed by Langmuir isotherm. Energy-dispersive X-ray fluorescence (EDXRF) analysis and powder X-ray diffraction analysis further confirms the uranium adsorption to the EPS gel of S. elongatus BDU130911. The culture filtrate of S. elongatus BDU130911 exhibited biosurfactant property and formed a stable emulsion with petrol (EI24 51.2%) due to the presence of uronic acid and rhamnose sugar. These findings suggest that the EPS of S. elongatus BDU130911 biomass has the potential to be used as a green adsorbing agent for the effective extraction of radionucleotide and petroleum hydrocarbons.