Characterization of Biopolymers in Water Based on their Enzymatic Degradability

Abstract

 Although water/wastewater treatment using membrane technology has various advantages over conventional methods, membrane fouling still impedes wide-spread use of the technology. Recent studies have demonstrated that high-molecular-weight hydrophilic organic matters (i.e., biopolymers) play an important role in the evolution of membrane fouling. However, detailed information on biopolymers such as molecular composition and structure is still unknown. In this study, biopolymers were collected and isolated from surface water and municipal wastewater, and their degradability by enzymes was investigated. Enzymes that could degrade specific structures of polysaccharides and proteins (α-amylase, cellulase, protease, and lysozyme) were used in this study. LC-OCD analysis could detect degradation of biopolymers (i.e., shift of molecular weight distribution) caused by enzymes, which cannot be detected by common analytical methods. Biopolymers isolated from surface water were degraded by α-amylase and cellulase, whereas biopolymers isolated from municipal wastewater were degraded by lysozyme. These results clearly indicate that the two biopolymer samples examined in this study had different structures and properties, which has not been clearly shown so far. Use of various combinations of biopolymers and enzymes in the method established in this study may deepen understanding of the structure of biopolymers.