Comparative Sugar Yield from Lime Pretreated Lignocellulo-Starch Biomass during Enzymatic Saccharification with Binary or Triple Enzyme Cocktails

Abstract

The comparative sugar recovery from lime pretreated lignocellulo-starch biomass (LCSBs) during saccharification with single, binary or triple enzyme systems was investigated. Reducing sugar (RS) (Irelease was the highest from lime pretreatment at room temperature (30 ±1 ºC) for 24 h (LRT1) compared to 48 h (LRT2) or high temperature (121 ºC; 60 min.; LHT) treatments when saccharified with commercial cellulase (Ecozyme RT80) alone. Supplementation with amylolytic enzyme, Stargen after 72 h (binary system) remarkably enhanced the RS yield at 96 h, which then tapered off at 120 h. Reversal of the enzyme application sequence with Stargen+Ecozyme RT80 resulted in poor saccharification up to 48 h followed by a rapid rise in RS release after supplementation with EcozymeRT80, which was due to the preferential saccharification of starch and exposure of cellulose for hydrolysis. Supplementation of xylanase (Ecozyme XY50) along with the other two enzymes (triple enzyme system) was beneficial in the case of LCSBs such as peels of greater yam, beet root and ash gourd having high hemicelluloses content. Overall Conversion Efficiency was not significantly different for the binary and triple enzyme based saccharification for most residues, indicating the possibility of cost saving of enzymes depending on the type of biomass.