Comparison Of Seven Extraction Methods For Extracellular Polymeric Substances From Acidithiobacillus Ferrooxidans

The efficiencies of extracting extracellular polymeric substances (EPS) from Acidithiobacillus ferrooxidans (A. ferrooxidans) using ethylene diamine tetraacetic acid disodium salt (EDTA), cation exchange resin (CER), NaOH, H2SO4, heating method, sonication and centrifugation were compared. EPS constituents such as carbohydrate, protein, nucleic acid were analyzed. Results showed that EDTA method was most effective in extracting EPS from A. ferrooxidans. For each gram of dry cells, 73.69mg of EPS was obtained. The quantification of EPS and the percentage of the three main components were strongly dependent upon the extraction methods. The UV visible spectrum was also employed to be used as an efficient and convenient way to evaluate the extent of cell lysis for making a judgment on EPS extraction methods.