title: Biochemical characterization and synergism of cellulolytic enzyme system from Chaetomium globosum on rice straw saccharification.
abstract: BACKGROUND
  Efficient hydrolysis of lignocellulosic materials to sugars for conversion to biofuels and chemicals is a key step in biorefinery. Designing an active saccharifying enzyme system with synergy among their components is considered a promising approach.
  
  
  RESULTS
  In this study, a lignocellulose-degrading enzyme system of Chaetomium globosum BCC5776 (CG-Cel) was characterized for its activity and proteomic profiles, and synergism with accessory enzymes. The highest cellulase productivity of 0.40 FPU/mL was found for CG-Cel under the optimized submerged fermentation conditions on 1% (w/v) EPFB (empty palm fruit bunch), 2% microcrystalline cellulose (Avicel®) and 1% soybean meal (SBM) at 30 °C, pH 5.8 for 6 d. CG-Cel worked optimally at 50-60 °C in an acidic pH range. Proteomics analysis by LC/MS/MS revealed a complex enzyme system composed of core cellulases and accessory hydrolytic/non-hydrolytic enzymes attacking plant biopolymers. A synergistic enzyme system comprising the CG-Cel, a β-glucosidase (Novozyme® 188) and a hemicellulase Accellerase® XY was optimized on saccharification of alkaline-pretreated rice straw by a mixture design approach. Applying a full cubic model, the optimal ratio of ternary enzyme mixture containing CG-Cel: Novozyme® 188: Accellerase® XY of 44.4:20.6:35.0 showed synergistic enhancement on reducing sugar yield with a glucose releasing efficiency of 256.4 mg/FPU, equivalent to a 2.9 times compared with that from CG-Cel alone.
  
  
  CONCLUSIONS
  The work showed an approach for developing an active synergistic enzyme system based on the newly characterized C. globosum for lignocellulose saccharification and modification in bio-industries.
authors.affiliation: The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Prachauthit Road, Bangmod, Bangkok, 10140, Thailand.
authors.forename: Wanwitoo
authors.initials: W
authors.lastname: Wanmolee
authors.affiliation: Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand.
authors.forename: Warasirin
authors.initials: W
authors.lastname: Sornlake
authors.affiliation: Bioprocess Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand.
authors.forename: Nakul
authors.initials: N
authors.lastname: Rattanaphan
authors.affiliation: Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand.
authors.forename: Surisa
authors.initials: S
authors.lastname: Suwannarangsee
authors.affiliation: The Joint Graduate School for Energy and Environment (JGSEE), King Mongkut's University of Technology Thonburi, Prachauthit Road, Bangmod, Bangkok, 10140, Thailand.|BIOTEC-JGSEE Integrative Biorefinery Laboratory, Innovation Cluster 2 Building, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand.
authors.forename: Navadol
authors.initials: N
authors.lastname: Laosiripojana
authors.affiliation: Enzyme Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand. verawat@biotec.or.th.|BIOTEC-JGSEE Integrative Biorefinery Laboratory, Innovation Cluster 2 Building, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand. verawat@biotec.or.th.
authors.forename: Verawat
authors.initials: V
authors.lastname: Champreda
mesh_terms: D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism*; D002597:Chaetomium / Q000201:enzymology*; D004357:Drug Synergism; D004789:Enzyme Activation; D008031:Lignin / Q000737:chemistry*; D009097:Multienzyme Complexes / Q000737:chemistry; D012275:Oryza / Q000737:chemistry* / Q000382:microbiology; D018547:Plant Stems / Q000737:chemistry* / Q000382:microbiology; D013379:Substrate Specificity
chemical_list: D009097:Multienzyme Complexes; C036909:lignocellulose; D008031:Lignin; D002480:Cellulase
keywords: Cellulase; Chaetomium globosum; Lignocellulose; Saccharification; Synergistic action