초록
<P><B>Abstract</B></P> <P>We investigated the feasibility of bioethanol production from hydrolysate of green seaweed <I>Ulva rigida</I>. The pretreatment of the green macroalgae was optimized using thermal acid hydrolysis to obtain a high reducing sugars yield. The dry seaweed biomass, (5 to 15% <I>w</I>/<I>v</I>) was hydrolyzed with two different acid catalysts, H<SUB>2</SUB>SO<SUB>4</SUB> and HCl at a concentration of 0 to 10.0% (<I>v</I>/v). The hydrolysis times ranging from 30 to 60min were investigated when the mixture was autoclaved. A condition of 4% (<I>v</I>/v) sulfuric acid, 10% (<I>w</I>/<I>v</I>) biomass loading and 1h of incubation time was optimum to obtain maximum total fermentable reducing sugar concentration of 34±0.25mg/ml and 0.50±0.02mg/ml of phenolic compounds. Fermentation of the hydrolysate using adapted and non-adapted <I>Pachysolen tannophilus</I> produced 0.12g/g and 0.09g/g (ethanol to dry seaweed), respectively. These preliminaries results indicate a potential use of the macroalgae <I>U. rigida</I> for bioethanol production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Green seaweed <I>Ulva rigida</I> was characterized as feedstock for bioethanol production. </LI> <LI> Acid hydrolysis is effective for hydrolysis of <I>Ulva</I> sugars using mild conditions. </LI> <LI> <I>Ulva</I> hydrolysate was used as substrate for fermentation. </LI> <LI> Biological adaptation gave better ethanol production from <I>Ulva</I> hydrolysate. </LI> <LI> Ethanol yield obtained was 0.37g/g sugar consumed accounting for 73% efficiency </LI> </UL> </P>