Increase of ethanol production from molasses by co-fermentation with cassava waste hydrolysate

Abstract

Comparison of cassava waste pulp hydrolysate obtained from hydrochloric acid and 3 different enzymes (cellulase, alpha-amylase and glucoamylase). Consequently hydrolysis, revealed that 10% and 25% (w/v) substrate loading of The CWP-acid and enzymatic hydrolysate contained maximal reducing sugar at 0.28 and 0.14 g/g dry weight, respectively. But the CWP-enzymatic hydrolysate gave 62.47% higher ethanol than the CWP-acid hydrolysate when they fermented by Saccharomyces cerevisiae TISTR 5606 (SC 90). Co-fermentation of molasses with the CWP-enzymatic hydrolysate at initial total sugar 24.5% (w/v) yielded maximal ethanol 6.67% (w/v). Fermentation of the molasses-CWP enzymatic hydrolysate mixture by supplementation with 0.8% (w/v) KH2PO4 increased maximal ethanol to 7.09% (w/v). This maximal level of ethanol could be increased to 7.44% (w/v) by addition of 3% (w/v) of solid residue obtained after enzymatic hydrolysis of cassava waste pulp.