Characterizing the Composition of the Secreted Biopolymer

Abstract Several strains of bacterium produce a biopolymer with different properties. For studying this biopolymer, its relative solubility in organic and inorganic solvents was studied after harvesting it from bacillus culture. Then, using a variety of methods, the coexistence of lipids, sugars and proteins and other compounds in the biopolymer network was examined. Addition of EDTA, sodium hydroxide and dilution of biopolymer solution led to precipitation of some part of this biopolymer as white powder which indicated its polysaccharide properties. The coexistence of polysaccharide and lipids in biopolymer was consequently shown by Mulish and Dyer/or Bligh Test. Adoption of Lowry and Bradford methods showed that the biopolymer composition has been mixed with proteins. Further studies on these proteins were performed by Native & denaturing Electrophoresis & UV-Vis spectroscopy. The results of SDS-PAGE method showed small protein bands with 12-66 kDa in MW. The Native Electrophoresis results indicated that this protein can not run of Electrophoresis due to binding of polymer network by non-covalent bands. Furthermore, the UV-Vis spectroscopy of biopolymer did not show any protein peak. This result indicated that the proteins of biopolymer have been trapped in polymer network. In summary, the results show that this polymer has multi-substance Native.