Identification of novel bacterial expansins and their synergistic actions on cellulose degradation.
Novel expansins, non-catalytic proteins which induce weakening of the rigid cellulose structure, have been identified in this study. A pipeline of bioinformatics was implemented for sequence and structure-based prediction of putative bacterial expansin-like group × family from NR databases. All putative expansins had no detectable activity against cellulosic and hemicellulosic substrates but showed varying degrees of synergy (2.0-7.6 folds) with the commercial Trichoderma reesei cellulase (Celluclast™ 1.5L) on degradation of filter paper in order of BpEX ≈ CmEX > MaEX > PcEX > SaEX. A mixture design with full cubic model predicted optimal formulation comprising Celluclast™: CmEX from Clavibacter michiganensis = 72.4%: 27.6%, with no synergy of β-glucosidase on degradation of alkaline pretreated rice straw. Under these conditions, the reducing sugar yield was 163.6% compared with the reaction containing cellulase alone. This work demonstrated the potential benefit of novel bacterial expansins on enhancing cellulose degradation efficiency in lignocellulosic biomass degradation.
['Bunterngsook|Benjarat|B|', 'Mhuantong|Wuttichai|W|', 'Champreda|Verawat|V|', 'Thamchaipenet|Arinthip|A|', 'Eurwilaichitr|Lily|L|']
D001426:Bacterial Proteins D002480:Cellulase D002482:Cellulose D019295:Computational Biology D004591:Electrophoresis, Polyacrylamide Gel D005798:Genes, Bacterial D006868:Hydrolysis D008031:Lignin D012044:Regression Analysis D014242:Trichoderma
Expansin Synergy Cellulase Mixture design Lignocellulose