ORIGINAL ARTICLE Bamboo fibre processing: insights into hemicellulase and cellulase substrate accessibility JIAJIA FU 1,2 , GIBSON S. NYANHONGO 3 , CARLA SILVA 4 , MASSIMILIANO CARDINALE 3 , ENDRY NUGROHO PRASETYO 3 , CHONGWEN YU 2 , ARTUR CAVACO-PAULO 4 & GEORG M. GÜBITZ 3 1 College of Textiles & Clothing, Jiangnan University,Wuxi, 214122, P. R. China, 2 Key Laboratory of Science & Technology of Eco-Textile (Donghua University/Jiangnan University), Ministry of Education, P. R. China, 3 Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12/1, Graz, Austria, and 4 Department of Textile Engineering, University of Minho, 4800-058 Guimarães, Portugal Abstract A biological approach for degumming bamboo substrates has been assessed. The ability of various commercially available enzymes, including cellulase, xylanase, pectinase and mannanase, to hydrolyze bamboo powders was investigated. In addi- tion, a commercial cellulase preparation was applied onto bamboo fibre bundles obtained by natural retting. It was found that almost all enzymes applied can use bamboo material as a substrate. Mild autoclave pre-treatment can enhance reduc- ing sugar yield from different enzyme treatments. A most pronounced effect was observed with cellulase treatment in which the hydrolysis degree increased 1.7 fold as measured by reducing sugars for autoclave pre-treated bamboo powders versus non-treated powders after only a short period of incubation. The combined treatment of hemicellulase preparations showed no effect on the hydrolysis of bamboo substrates. The effect of autoclave pre-treatment on cellulase-treated samples was confirmed by the increase of sugar yield, protein absorption as well as by the enhancement of surface modification and enzyme penetration observed by CLSM (confocal laser scanning microscopy). This work establishes a base for future studies to develop enzymatic hydrolysis of bamboo materials, making them suitable for textile processing. Keywords: bamboo , cellulase, xylanase, pectinase, mannanase, autoclave, CLSM Correspondence: C. Yu, College of Textiles, Donghua University, Shanghai, 201620. Tel: +86 21 67792664. Fax: +86 21 67792664. Email: yucw@dhu.edu.cn; A. Cavaco-Paulo, University of Minho, Campus de Azurém, 4800-058 Guimarães. Tel: 351-253-510271. Fax: 351-253-510293. E-mail: artur@det.uminho.pt Biocatalysis and Biotransformation, January–February 2012; 30(1): 27–37 ISSN 1024-2422 print/ISSN 1029-2446 online © 2012 Informa UK, Ltd. DOI: 10.3109/10242422.2012.644440 Introduction Bamboo is a giant woody, tree-like, perennial ever- green plant belonging to a primitive subfamily of grasses (Sathitsuksanoh et al. 2010). With more than 87 genera and 1,500 species worldwide (Diver 1976), bamboo constitutes an economically important group of plants, especially in Asia (Parameswaran & Liese 1976). Currently, bamboo is emerging as a natural, eco-friendly raw material in the textile indus- try due to its many attractive properties such as fast- est growth rate of any known plant, anti-microbial properties, etc. Structurally, bamboo fibres are dis- tributed in the internodes of vascular bundles as fibre caps or sheaths surrounding the conducting elements (including vessels, sieve tubes and compan- ion cells) (Liese 1998), which contributes to the superior strength and toughness of bamboo culm. A single bamboo fibre (monofilament) varies between 1.5 and 4.5 mm in length (Liese 1987). Caustic soda degumming is most widely applied on bamboo pro- cessing, and considerable research has been focused on this method (Shi et al. 2005; Wang et al. 2005; Xu &Tang 2006;Wang et al. 2007; Das & Chakraborty 2008). Such a process requires high chemical con- sumption and energy input, produces hazardous waste resulting in serious environmental pollution, damages the fibre quality (Brülmann et al. 2007; Zheng et al. 2001; Fu et al. 2008) and cannot be tailored to selectively produce fibre bundles. A semi- controlled degumming technique is required to pro- cess the bamboo culms, in which a certain amount of gummy material or non-cellulosic substances is maintained to aggregate single fibres and form the fibre bundles necessary for spinning requirements. Biocatal Biotransformation Downloaded from informahealthcare.com by Prof. Artur Cavaco-Paulo on 03/07/12 For personal use only.