Comparison of steam-alkali -chemical and microwave-alkali pretreatment for enhancing the enzymatic saccharification of oil palm trunk

This paper demonstrates two different pretreatment protocols for oil palm trunks (OPT); steam-alkali chemical (SAC) and microwave-alkali (Mw-A) method. The composition, morphology, structure and crystallinity of OPT before and after pretreatment were analyzed. The effectiveness of the pretreated methods was investigated by performing enzymatic saccharification on the OPT. The physiochemical factors namely: enzyme ratio (cellulase to beta-glucosidase), pH, temperature and substrate loading (w/v) on enzymatic saccharification were also investigated. The pre-determined optimal conditions were then used for further enzymatic hydrolysis of raw and pretreated OPT substrates. The results revealed a huge degree of reduction in lignin, up to 89% for SAC treated OPT and at least 15% for Mw-A treated OPT sample as compared to untreated ones. High glucose accumulation (79.4%) was obtained after 72 h saccharification for both pretreated OPT samples. (C) 2016 Elsevier Ltd. All rights reserved.