Eucheuma cottonii able to be used as bioethanol fermentation substrate in the form of reduction sugars by
enzymatic hydrolysis using cellulose enzymes. The best conditions of the enzymatic hydrolysis of cellulose
enzymes was 36 AU with temperature of 50°C and reduction sugar obtained was 8.045 mg/ml or 0.865%. However,
based on t-test statistical analysis the results of reduction sugar levels were not significantly different with the result
of cellulase enzymes hydrolysis at a temperature of 50°C, 19 AU which produced reduction sugar levels at 7.937
mg/ml or 0.794%.