Sequential acid and enzymatic hydrolysis in situ and bioethanol production from Gracilaria biomass.

Highlights: [•] Red seaweed Gracilaria sp. was used as a feedstock for bioethanol production. [•] Sequential acid and enzyme hydrolysis in situ resulted in a high quality hydrolysate. [•] Ethanol production using hydrolysate of Gracilaria was by free and immobilized yeast. [•] Ethanol yield obtained was 0.48g/g sugar consumed accounting for 94% efficiency. [•] 1g of dry Gracilaria was converted to 0.236g of ethanol via the developed processes. [ABSTRACT FROM AUTHOR]