Sugar concentration of Gracilaria sp. following hydrolysis using cellulase and sulphuric acid and several pretreatment methods

In the search for new and renewable energy, Gracilaria sp. was studied as the raw material for bioethanol production. This seaweed is available abundantly in the very long Indonesian coastline. This study investigates the effect of several pretreatment methods on the concentration of sugar produced from Gracilaria sp. when hydrolyzed using cellulase or sulphuric acid. Reducing sugar was measured by UV-Vis spectrophotometry using Nelson-Somyogi reagent and the ethanol concentration was measured by using gas chromatography. Cellulase and sulphuric acid (H2SO4) were used in the hydrolysis. Cellulase concentration used was 200, 400, 600 and 800 units/ml, whereas the concentration of sulphuric acid used was 1%, 3%%, 5%, and 7%. The highest concentration of reducing sugar was produced by hydrolysis using H2SO4 1%.