Enzymatic hydrolyzing performance of Acremonium cellulolyticus and Trichoderma reesei against three lignocellulosic materials

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Bioethanol isolated from lignocellulosic biomass represents one of the most promising renewable and carbon neutral alternative liquid fuel sources. Enzymatic saccharification using cellulase has proven to be a useful method in the production of bioethanol. The filamentous fungi <jats:italic>Acremonium cellulolyticus</jats:italic> and <jats:italic>Trichoderma reesei</jats:italic> are known to be potential cellulase producers. In this study, we aimed to reveal the advantages and disadvantages of the cellulase enzymes derived from these fungi.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>We compared <jats:italic>A. cellulolyticus</jats:italic> and <jats:italic>T. reesei</jats:italic> cellulase activity against the three lignocellulosic materials: eucalyptus, Douglas fir and rice straw. Saccharification analysis using the supernatant from each culture demonstrated that the enzyme mixture derived from <jats:italic>A. cellulolyticus</jats:italic> exhibited 2-fold and 16-fold increases in Filter Paper enzyme and β-glucosidase specific activities, respectively, compared with that derived from <jats:italic>T. reesei</jats:italic>. In addition, culture supernatant from <jats:italic>A. cellulolyticus</jats:italic> produced glucose more rapidly from the lignocellulosic materials. Meanwhile, culture supernatant derived from <jats:italic>T. reesei</jats:italic> exhibited a 2-fold higher xylan-hydrolyzing activity and produced more xylose from eucalyptus (72% yield) and rice straw (43% yield). Although the commercial enzymes Acremonium cellulase (derived from <jats:italic>A. cellulolyticus</jats:italic>, Meiji Seika Co.) demonstrated a slightly lower cellulase specific activity than Accellerase 1000 (derived from <jats:italic>T. reesei</jats:italic>, Genencor), the glucose yield (over 65%) from lignocellulosic materials by Acremonium cellulase was higher than that of Accellerase 1000 (less than 60%). In addition, the mannan-hydrolyzing activity of Acremonium cellulase was 16-fold higher than that of Accellerase 1000, and the conversion of mannan to mannobiose and mannose by Acremonium cellulase was more efficient.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion</jats:title> <jats:p>We investigated the hydrolysis of lignocellulosic materials by cellulase derived from two types of filamentous fungi. We found that glucan-hydrolyzing activity of the culture supernatant from <jats:italic>A. cellulolyticus</jats:italic> was superior to that from <jats:italic>T. reesei</jats:italic>, while the xylan-hydrolyzing activity was superior for the cellulase from <jats:italic>T. reesei</jats:italic>. Moreover, Acremonium cellulase exhibited a greater glucan and mannan-hydrolyzing activity than Accellerase 1000.</jats:p> </jats:sec>