Comparison of Extraction Methods for Quantifying Extracellular Polymers of Marine Algae

Five extraction methods were used to extract extracellular polymers (EPS) from Platymonas subcordiformis. Results suggested that the extraction efficiencies of EPS decreased as followed: cation exchange resin (CER) > ultrasonic extraction> heating (80°C) > EDTA > centrifugation. CER method was the most effective in the EPS extraction from P. subcordiformis with the highest amount of EPS and the lowest cell lysis, while the ultrasonic extraction method was not suitable to extract EPS for its obvious cell lysis. In addition, heating (80 °C) was used to investigate EPS formation of P. subcordiformis. Results showed EPS amount increased at the increased incubation time when the nutrients were enough whereas the ratio of EPS components remained unchanged in the growing cycle.