Conference article

The marine macro-alga Nizimuddinia zanardini was harvested from Persian Gulf to assess its biomass for fermentable sugar production. Hydrolysis of the macro-alga was investigated in two stages to evaluate the conversion of cellulose and hemicelluloses in biomass to corresponding monomeric sugars. The biomass was first subjected to dilute sulfuric acid pretreatments at 121 °C and then to enzymatic saccharification (45°C; pH 4.8) at different retention times. The results showed the ability of the first stage hydrolysis in depolymerization of xylan to xylose with a maximum yield of 64% (based on total xylose content) at 7% (w/w) acid concentration for 60 min. However; the yield of glucose from glucan was relatively low in the acid hydrolysis with a maximum of 14.4% (based on total glucan content) at 7% (w/w) acid concentration for 60 min. Under these conditions; no hydroxymethyl furfural (HMF) produced. Formation of furfural depended on the retention time and acid concentration; whereas the concentration of acetic acid was almost constant at retention times higher than 45 min and acid concentration of 7 %.The solid residuals were then subjected to enzymatic hydrolysis. The maximum yield of glucose from the macro-alga by enzymatic saccharification (45°C; pH 4.8; 24 h); using cellulase and ß-glucosidase; was 70.2 g/kg (70.2% yield based on total glucan content).

Enzymatic hydrolysis; Dilute-acid hydrolysis; Macro-alga; Pretreatment