Chemical composition, saccharification yield, and the potential of the green seaweed Ulva pertusa

Abstract

Recently, seaweeds have gained attention as possible renewable sources for biofuel and bioproduct production. To investigate the possibility of using green seaweeds as biomass feedstocks, the chemical composition and saccharification yield of the green seaweed Ulva pertusa were investigated. In this study, we evaluated U. pertusa that was harvested from the seashore in Jeju Island, Korea. By proximate composition analysis, dried U. pertusa was found to contain 52.3% carbohydrate, 25.1% protein, 0.1% lipid, and 22.5% ash. The elemental analysis of U. pertusa indicated the content of carbon to be 34.9%, hydrogen 5.3%, oxygen 46.5%, nitrogen 3.8%, sulfur 3.1%, and phosphorous 0.12%. The optimal conditions for the acid hydrolysis and saccharification of U. pertusa were investigated by varying the types of catalysts, catalyst concentration, reaction time, reaction temperature, and seaweed concentration. Under optimized acid hydrolysis condition, 32.9% of seaweed was recovered as monosaccharides and the monosaccharide composition was 11.5% D-glucuronic acid and D-glucuronic acid lactone, 11.1% L-rhamnose, 6.7% D-glucose, and 3.7% D-xylose. The concept of degree of reductance was introduced to assess the potential of U. pertusa as an industrial feedstock. It was found that the degree of reductance of U. pertusa was lowest among the biomass considered in this study. Based on the comparison of chemical composition and reductance degree of various biomass resources, the competitiveness of U. pertusa as a biomass feedstock for biofuel and bioproduct production was discussed.