Bioethanol production from Gracilaria verrucosa, a red alga, in a biorefinery approach

In this study, Gracilaria verrucosa, red seaweed has been used for production of agar and bioethanol. The algae harvested at various time durations resulted in extraction of similar to 27-33% agar. The leftover pulp was found to contain similar to 62-68% holocellulose, which on enzymatic hydrolysis yielded 0.87 g sugars/g cellulose. The enzymatic hydrolysate on fermentation with Saccharomyces cerevisiae produced ethanol with an ethanol yield of 0.43 g/g sugars. The mass balance evaluation of the complete process demonstrates that developing biorefinery approach for exploiting Gracilaria verrucosa, a red alga, could be commercially viable. (C) 2012 Elsevier Ltd. All rights reserved.