Composition of Extracellular and Intracellular Polymeric Substances Produced by Scenedesmus and Microcystis

摘要

Algal extracellular and intracellular polymeric substances (EPS and IPS) are widely applied in fields such as food, cosmetics, and wastewater treatment. Algal IPS content was much higher than EPS and thus extracting IPS from algal biomass may greatly improve the commercial value of algal cultivation. This study was to provide a basis for development of algal IPS by comparing composition of algal IPS and EPS. EPS and IPS produced by Scenedesmus and Microcystis, which commonly dominates the freshwater ecosystems, were analyzed using fluorescence excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC). The IPS concentration of Scenedesmus obliquus and Microcystis aeruginosa was 1.2 to 2.1 times higher than EPS concentration. The maximum EPS concentration was 145.7mg C/L but the maximum IPS concentration reached 206.1mg C/L. Seven components including five humic-like components (C1, C2, C3, C4, and C7) and two tryptophan-like component (C5 and C6) were identified by EEM-PARAFAC. All seven components identified in the current study were considered effective in removing heavy metals. Therefore, IPS of M. aeruginosa would be potential polymeric substances for environmental biotechnology.