Simultaneous saccharification and fermentation of paper sludge without pretreatment using cellulase from Acremonium cellulolyticus and thermotolerant Saccharomyces cerevisiae

► Cellulase was produced untreated paper sludge for bioethanol production. ► CMCase activity was fivefold improved using mutagenic cocktail. ► Bioethanol was produced from untreated paper sludge in SSF process. ► Ethanol yield was 23.6% based on paper sludge cellulose.