Aparna Banerjee
The University of Burdwan, India
Title: Synthesis of nanoparticle using dextran-like exopolysaccharide extracted from thermophilic bacteria and its biological activity
Biography
Biography: Aparna Banerjee
Abstract
Hot water springs are among one of the least explored ecosystem around earth. Geological Survey of India (GSI) has identified around 350 geothermal hot springs in India; most of which have surface temperature ranging from 37ºC-90ºC and many are not explored yet. Water sample is collected from a least explored basic hot spring of West Bengal, India and is not famous for the tourists also. Isolated different bacterial samples were characterized using fluorescence, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Different biochemical characterizations, viz. extracellular enzymes production, antibiotic sensitivity, thermal death point and carbohydrate fermentation were also performed. Out of all the isolates, two showed good exopolysaccharide (EPS) production. For morphological characterization of the EPS, congo red staining, SEM and atomic force microscopic (AFM) studies are done. Elemental analysis, X-ray diffraction (XRD), Fourier Transformed Infrared spectroscopy (FTIR), 1H Nuclear Magnetic Resonance (NMR) Spectroscopy, Thermogravimetric analysis, Differential Scanning Calorimetric, rheological studies were performed for physical characterization of EPSs. Maximum EPS production was 7.66g/l with ethyl acetate as a solvent. 1H NMR study showed the spectrum similar to dextran. UV-B tolerance, antioxidant activity, food texture enhancing capacity and emulsification activity of the EPSs are also checked. As the AFM study revealed nanoparticle like homogenous, sharp and equally distributed molecular structure of the EPSs, silver and gold EPS nanoparticle were prepared and it showed promising antimicrobial activity.