الفهرس 
List of contentsOnly 14 pages are availabe for public view
 |  | from | 206 |  |  |
| | | from | 206 | | |
Abstract
Isolation, purification and characterization of three cyanobacterial sp. selection of N. carneum for thesis study due to its high yield of EPS (1.121 g / L). Protein content and dry weight were used for characterization of N. carneum growth. The physico-chemical characterization of the cyanobacterium Nostoc carneum extracellular polysaccharide (EPS) was studied. Two sugars moieties glucose (105.5 mg/g EPS) and xylose (215.2 mg/g EPS) were involved in the polysaccharide composition as well as the presence of sulfate, uronic acids, and protein. The in vitro antioxidant assays (reducing power & DPPH) showed that N. carneum EPS possess antioxidant activity. Fourier Transformed Infrared (FT-IR) spectra of EPS showed a specific absorbance of O-H and –NH stretching, asymmetrical-symmetrical C-H stretching, Presence of sulfur containing functional groups and carboxylic acids. The thermal gravimetric and differential scanning calorimetric analyses confirmed that polysaccharide thermal stability was around 237 Co. N. carneum exopolymer showed pseudoplastic non-Newtonian fluid behavior in the aqueous solutions as well as increasing viscosity with increasing concentration. Ther are different factors affecting production of exopolysaccharide secreted by Nostoc carneum such as nitrogen content of growth media, NaCl supplementation, pH of the media and addition of chromium. Exopolysaccharide of N. carneum promoted growth of pea and wheat plants as well as removal of heavy metals ( Cu and Co) and dyes (safranin and methyl orange).