期刊名称：International Journal of Environment and Bioenergy
电子版ISSN：2165-8951
出版年度：2012
卷号：3
期号：2
页码：98-110
语种：English
出版社：Modern Scientific Press
摘要：Macroalgae or seaweed is considered being promising feedstock for bioethanol production because of high polysaccharides content. Those can be converted into fermentable sugar through acid and enzymatic hydrolysis. The research objective is to develop bioethanol production from red macroalgae through acid hydrolysis and yeast adaptation. Polysaccharides of red algae Euchema cottonii consist of 26.9% carbohydrates, 2.93% hemicelluloses and 10.3% cellulose. Acid hydrolysis at temperature of 121℃, 1.5 bars, at 15.0% dry seaweed produced hydrolysates with reducing sugar content in the range of 1.33-3.28% (w/v). Continued enzymatic hydrolysis increased reducing sugar up to 5.02% (w/v). Native yeast growth on acid hydrolysates which had 3.15% reducing sugar showed low metabolismc activity. Adaptation of S. cerevisiae yeast can improve the ability of yeasts to produce ethanol from acid seaweed hydrolysate. Adaptation of S. cerevisiae IPBCC resulted in the highest cell density from adaptation I to IV, followed by bulk yeast and commercial yeast. With the long process of adaptation, the cells density tends to decrease and the residual reducing sugar tends to increase. The highest ethanol production of adapted IPBCC yeast was 2.20% (v/v, ethanol in fermentation broth), with 80.3% substrate efficiency and 48.9% fermentation efficiency. While the highest ethanol production of adapted bulk yeast is 1.96% (v/v, ethanol in fermentation broth), which has 85.05% substrate efficiency and 42.71% fermentation efficiency.
