Interactive forces between lignin and cellulase as determined by atomic force microscopy

Biotechnology for Biofuels

Chengrong Qin²  Kimberley Clarke¹  Kecheng Li¹ 

[1] Department of Chemical Engineering, University of New Brunswick, 2 Garland Court, Incutech Complex, Fredericton, NB E3B 5A3, Canada

[2] College of Light Industry and Food Engineering, Guangxi University, 100 University Road, Nanning, Guangxi Province 530004, PR China

关键词: Cellulase;    Atomic force microscopy;    Enzymatic hydrolysis;    Lignin;    Non-productive binding;   

Others  :  792605
DOI  :  10.1186/1754-6834-7-65

 received in 2014-01-15, accepted in 2014-04-03,  发布年份 2014

【 摘 要 】

Background

Lignin is a complex polymer which inhibits the enzymatic conversion of cellulose to glucose in lignocellulose biomass for biofuel production. Cellulase enzymes irreversibly bind to lignin, deactivating the enzyme and lowering the overall activity of the hydrolyzing reaction solution. Within this study, atomic force microscopy (AFM) is used to compare the adhesion forces between cellulase and lignin with the forces between cellulase and cellulose, and to study the moiety groups involved in binding of cellulase to lignin.

Results

Trichoderma reesei, ATCC 26921, a commercial cellulase system, was immobilized onto silicon wafers and used as a substrate to measure forces involved in cellulase non-productive binding to lignin. Attraction forces between cellulase and lignin, and between cellulase and cellulose were compared using kraft lignin- and hydroxypropyl cellulose-coated tips with the immobilized cellulase substrate. The measured adhesion forces between kraft lignin and cellulase were on average 45% higher than forces between hydroxypropyl cellulose and cellulase. Specialized AFM tips with hydrophobic, -OH, and -COOH chemical characteristics were used with immobilized cellulase to represent hydrophobic, H-bonding, and charge-charge interactions, respectively. Forces between hydrophobic tips and cellulase were on average 43% and 13% higher than forces between cellulase with tips exhibiting OH and COOH groups, respectively. A strong attractive force during the AFM tip approach to the immobilized cellulase was observed with the hydrophobic tip.

Conclusions

This work shows that there is a greater overall attraction between kraft lignin and cellulase than between hydroxypropyl cellulose and cellulase, which may have implications during the enzymatic reaction process. Furthermore, hydrophobic interactions appear to be the dominating attraction force in cellulase binding to lignin, while a number of other interactions may establish the irreversible binding.

【 授权许可】

   
2014 Qin et al.; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Wyman CE: What is (and is not) vital to advancing cellulosic ethanol. Trends Biotechnol 2007, 25:153-156.
• [2]Himmel ME, Ding SY, Johnson DK, Adney WS, Nimlos MR, Brady JW, Foust TD: Biomass recalcitrance: engineering plants and enzymes for biofuels production. Science 2007, 315:804-807.
• [3]Perez J, Munoz-Dorado J, de la Rubia T, Martinez J: Biodegradation and biological treatments of cellulose, hemicellulose and lignin: an overview. Int Microbiol 2002, 5:53-63.
• [4]Kadla J, Kubo S: Miscibility and hydrogen bonding in blends of poly (ethylene oxide) and kraft lignin. Macromolecules 2003, 36:7803-7811.
• [5]Ooshima H, Burns DS, Converse AO: Adsorption of cellulase from Trichoderma reesei on cellulose and lignacious residue in wood pretreated by dilute sulfuric acid with explosive decompression. Biotechnol Bioeng 1990, 36:446-452.
• [6]Seawalt VJH, Glasser WG, Beauchemin KA: Lignin impact on fiber degradation. 3. Reversal of inhibition of enzymatic hydrolysis by chemical modification of lignin and by additives. J Agric Food Chem 1997, 45:1823-1828.
• [7]Berlin A, Gilkes N, Kurabi A, Bura R, Tu M, Kilburn D, Saddler J: Weak lignin-binding enzymes. Appl Biochem Biotechnol 2005, 163:121-124.
• [8]Lu Y, Yang B, Gregg D, Saddler J, Mansfield SD: Cellulase adsorption and an evaluation of enzyme recycle during hydrolysis of steam-exploded softwood residues. Appl Biochem Biotechnol 2002, 98–100:641-654.
• [9]Seawalt VJH, Od O, Glasser WG, Fontenot JP: Lignin impact on fibre degradation. 2. A model study using cellulosic hydrogels. J Sci Food Agric 1996, 71:204-208.
• [10]Olsen SN, Bohlin C, Murphy L, Borch K, McFarland KC, Sweeny MD, Westh P: Effects of non-ionic surfactants on the interactions between cellulases and tannic acid: a model system for cellulase-poly-phenol interactions. Enzyme Microb Technol 2011, 49:353-359.
• [11]Tu M, Pan X, Saddler JN: Adsorption of cellulase on cellulolytic enzyme lignin from lodgepole pine. J Agric Food Chem 2009, 57:7771-7778.
• [12]Börjesson J, Engqvist M, Sipos B, Tjerneld F: Effect of poly (ethylene glycol) on enzymatic hydrolysis and adsorption of cellulase enzymes to pretreated lignocellulose. Enzyme Microb Technol 2007, 41:186-195.
• [13]Zheng Y, Pan Z, Zhang R, Wang D, Jenkins B: Non-ionic surfactants and non-catalytic protein treatment on enzymatic hydrolysis of pretreated Creeping Wild Ryegrass. Appl Biochem Biotechnol 2008, 146:231-248.
• [14]Berlin A, Balakshin M, Gilkes N, Kadla J, Maximenko V, Kubo S, Saddler J: Inhibition of cellulase, xylanase and beta-glucosidase activities by softwood lignin preparations. J Biotechnol 2006, 125:198-209.
• [15]Binnig G, Quate CF: Atomic force microscope. Phys Rev Lett 1986, 56:930-933.
• [16]Meyer E: Atomic force microscopy. Prog Surf Sci 1992, 41:3-49.
• [17]Zhang M, Chen G, Kumar R, Xu B: Mapping out the structural changes of natural and pretreated plant cell wall surfaces by atomic force microscopy single molecular recognition imaging. Biotechnol Biofuels 2013, 6:147. BioMed Central Full Text
• [18]Zhang M, Wang B, Xu B: Measurements of single molecular affinity interactions between carbohydrate-binding modules and crystalline cellulose fibrils. Phys Chem Chem Phys 2013, 15:6508-6515.
• [19]Zhang M, Wu SC, Zhou W, Xu B: Imaging and measuring single-molecule interaction between a carbohydrate-binding module and natural plant cell wall cellulose. J Phys Chem B 2012, 116:9949-9956.
• [20]Grethlein HE: The effect of pore size distribution on the rate of enzymatic hydrolysis of cellulosic substrates. Nat Biotechnol 1985, 3:155-160.
• [21]Wong KKY, Deverell KF, Mackie KL, Clark TA, Donaldson LA: The relationship between fiber-porosity and cellulose digestibility in steam-exploded Pinus radiata. Biotechnol Bioeng 1988, 31:447-456.
• [22]Chandra RP, Bura R, Mabee WE, Berlin A, Pan X, Saddler JN: Substrate pretreatment: the key to effective enzymatic hydrolysis of lignocellulosics? Adv Biochem Eng Biotechnol 2007, 108:67-93.
• [23]Li X, Clarke K, Li K, Chen A: The pattern of cell wall deterioration in lignocellulose ifbers throughout enzymatic cellulose hydrolysis. Biotechnol Prog 2012, 28:1389-1399.
• [24]Mooney C, Mansfield SD, Touhy M, Saddler J: The effect of initial pore volume and lignin content on the enzymatic hydrolysis of softwoods. Bioresour Technol 1998, 64:113-119.
• [25]Tebeka IRM, Silva AGL, Petri DFS: Hydrolytic activity of free and immobilized cellulase. Langmuir 2009, 25:1582-1587.
• [26]Butt H-J, Cappella B, Kappl M: Force measurements with the atomic force microscope: Technique, interpretation and applications. Surf Sci Rep 2005, 59:1-152.
• [27]Colussi F, Garcia W, Rosseto FR, de Mello BL, de Oliveira Neto M, Polikarpov I: Effect of pH and temperature on the global compactness, structure, and activity of cellobiohydrolase Cel7A from Trichoderma harzianum. Eur Biophys J 2012, 41:89-98.
• [28]Wang QQ, Zhu JY, Hung CG, Zhan HY: Kinetics of adsorption, desorption, and re-adsorption of commercial endoglucanase in lignocellulosic suspensions. Biotechnol Bioeng 2013, 109:1965-1975.
• [29]Bose S, Barnes CA, Petrich JW: Enhanced stability and activity of cellulase in an ionic liquid and the effect of pretreatment on cellulose hydrolysis. Biotechnol Bioeng 2012, 109:434-443.
• [30]Sundari CS, Balasubramanian D: Hydrophobic surfaces in saccharide chains. Prog Biophys Mol Biol 1997, 67:183-216.
• [31]Kolpak FJ, Blackwell J: Determination of the structure of cellulose II. Macromolecules 1976, 9:273-278.
• [32]Petersen SB, Jonson PH, Fojan P, Peterson EI, Peterson MTN, Hansen S, Ishak RJ, Hough E: Protein engineering the surface of enzymes. J Biotechnol 1998, 66:11-26.
• [33]Gusakov AV, Sinitsyn AP, Berlin A, Markov AV, Ankudimova NV: Surface hydrophobic amino acid residues in cellulase molecules as a structural factor responsible for their high denim-washing performance. Enzyme Microb Technol 2000, 27:664-671.
• [34]Gilkes N, Henrissat B, Kilburn D, Miller RCJ, WRA J: Domains in microbial B-1, 4-glycanases: sequence conservation, function, and enzyme families. Microbiol Rev 1991, 55:303-315.
• [35]Goldstein MA, Takagi M, Hashida S, Shoseyov O, Doi RH, Segel IH: Characterization of the cellulose-binding domain of the Clostridium cellulovorans cellulose-binding protein A. J Bacteriol 1993, 175:5762-5768.
• [36]Petri DFS, Wenz G, Schunk P, Schimmel T: An improved method for the assembly of amino-terminated monolayers on SiO2 and the vapor deposition of gold layers. Langmuir 1999, 15:4520-4523.
• [37]Tan X, Li K: Adhesion forces between ligno-cellulose surfaces by atomic force microscopy. J Pulp Pap Sci 2008, 34:77-85.