title: Soluble inhibitors generated during hydrothermal pretreatment of oil palm mesocarp fiber suppressed the catalytic activity of Acremonium cellulase.
abstract: Oil palm mesocarp fiber was subjected to hydrothermal pretreatment under isothermal and non-isothermal conditions. The pretreated slurries were separated by filtration, pretreated liquids and solids were characterized. An enzymatic digestibility study was performed for both pretreated slurries and solids to understand the effect of soluble inhibitors generated during the pretreatment process. The highest glucose yield obtained from pretreated slurries was 70.1%, and gradually decreased with higher pretreatment severities. The highest glucose yield obtained in pretreated solids was 100%, after pretreatment at 210°C for 20min. In order to study the inhibitory effects of compounds generated during pretreatment with cellulase, technical grade solutions that mimic the pretreated liquid were prepared and their effect on Acremonium cellulase activity was monitored using Avicel. Xylo-oligomers and tannic acid were identified as powerful inhibitors of Acremonium cellulase, and the lowest hydrolysis rate of Avicel of 0.18g/g-glucose released/L/h was obtained from tannic acid.
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan; Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Electronic address: mohdrafein@upm.edu.my.
authors.forename: Mohd Rafein
authors.initials: MR
authors.lastname: Zakaria
authors.affiliation: Department of Materials and Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hirata
authors.affiliation: Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Izzudin
authors.initials: I
authors.lastname: Ibrahim
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Mohd Ali
authors.initials: MA
authors.lastname: Hassan
mesh_terms: D000164:Acremonium / Q000201:enzymology*; D000327:Adsorption; D002021:Buffers; D002244:Carbon / Q000737:chemistry*; D002480:Cellulase / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D004043:Dietary Fiber; D005947:Glucose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009844:Oligosaccharides / Q000737:chemistry; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry*; D013634:Tannins / Q000737:chemistry; D013696:Temperature
chemical_list: D002021:Buffers; D004043:Dietary Fiber; D009844:Oligosaccharides; D010938:Plant Oils; D013634:Tannins; D000073878:Palm Oil; D002244:Carbon; D002482:Cellulose; D002480:Cellulase; D005947:Glucose
keywords: Acremonium cellulase inhibition; Hydrothermal pretreatment; Oil palm mesocarp fiber; Tannic acid; Xylo-oligomers