| dc.description.abstract | Bioetanol is one of renewable energy source that can be obtained by fermentation and is environmental friendly. The production of bioetanol needs two important components that are the substrate and fermentation agent. Kappaphycus alvarezii is a potential subrate to be fermented by Saccharomyces cerevisiae, the most common microorganism for fermentation process. This study aimed at determining the ability of the 9th generation slow adapted S. cerevisiae strain (IPBCC 05.548 AL IX) to convert K. alvarezii hydrolysates into bioetanol. The yeast growth in hydrolysates and Yeast Malt Glucose Pepton (YMGP) was maximum at 42 hour incubation. In the hydrolysates, the cell size was relatively longer and the number of cells with large size were more than those in the YMGP. About 90 mL hydrolysates K. alvarezii that was fermentated with 10 mL of 106 mL-1 inoculum yielded maximum bioetanol 1,94% (v/v) at 168 hours incubation. Its fermentation, and substrate efficiency were 36,57%, and 59,85%, respectively. At the same incubation time and 106 cells mL-1 inoculum, 1,02% (v/v) bioetanol was yielded with fermentation, and substrate efficiency were 21,29%, and 70,07% respectively | en |
