Enzymatic conversion of lignocellulose into fermentable sugars: Challenges and opportunities

Biofuels, Bioproducts and Biorefining

Volumn 1, Issue 2, 2007, Pages 119-134

  Jørgensen, Henning ^a   Kristensen, Jan Bach ^a   Felby, Claus ^a  

^a UNIVERSITY OF COPENHAGEN   (Denmark)

Author keywords

Biorefinery; Cellulases; Hemicellulases; Pretreatment

Indexed keywords

BIOREFINERIES; CARBOHYDRATE SOURCES; ENZYMATIC CONVERSIONS; ENZYME PERFORMANCE; FERMENTABLE SUGARS; HEMICELLULASES; LIGNOCELLULOSIC SUBSTRATES; PILOT SCALE; PRE-TREATMENT; PRETREATMENT TECHNOLOGY; SCIENTIFIC ISSUES;

CARBOHYDRATES; CELLULOSE; COST REDUCTION; ENZYMES; FOSSIL FUELS; FUNCTIONAL GROUPS; GLUCOSE; LIGNIN; SUBSTRATES; SUGAR (SUCROSE);

ENZYMATIC HYDROLYSIS;

EID: 75949110177     PISSN: 1932104X     EISSN: 19321031     Source Type: Journal    
DOI: 10.1002/bbb.4     Document Type: Review

References (137)

1. Herrera S, Bonkers about biofuels. Nat Biotechnol 24:755-760 (2006).
2. Ragauskas AJ, Williams CK, Davison BH, Britovsek G, Cairney J, Eckert CA et al., The path forward for biofuels and biomaterials. Science 311:484-489 (2006).
3. Kamm B and Kamm M, Principles of biorefineries. Appl Microbiol Biotechnol 64: 137-145 (2004).
4. Hahn-Hägerdal B, Galbe M, Gorwa-Grauslund MF, Liden G and Zacchi G, Bio-ethanol-the fuel of tomorrow from the residues of today. Trends Biotechnol 24:549-556 (2006).
5. Thomsen MH, Thygesen A, Jørgensen H, Larsen J, Christensen BH and Thomsen AB, Preliminary results on optimization of pilot scale pretreatment of wheat straw used in coproduction of bioethanol and electricity. Appl Biochem Biotechnol 129-132:448-460 (2006).
6. Wyman CE, Dale BE, Elander RT, Holtzapple M, Ladisch MR and Lee YY, Coordinated development of leading biomass pretreatment technologies. Bioresource Technol 96:1959-1966 (2005).
7. Carpita N, Tierney M and Campbell M, Molecular biology of the plant cell wall: searching for the genes that define structure, architecture and dynamics. Plant Mol Biol 47:1-5 (2001).
8. Kuhad RC, Singh A and Eriksson KE, Microorganisms and enzymes involved in the degradation of plant fiber cell walls. Adv Biochem Eng Biotechnol 57:45-125 (1997).
9. Ding SY and Himmel ME, The maize primary cell wall microfibril: A new model derived from direct visualization. J Agric Food Chem 54:597-606 (2006).
10. Ward OP and Moo-Young M, Enzymatic degradation of cell wall and related plant polysaccharides. CRC Crit Rev Biotechnol 8:237-274 (1989).
11. Matthews JF, Skopec CE, Mason PE, Zuccato P, Torget RW, Sugiyama J et al., Computer simulation studies of microcrystalline cellulose Iβ. Carbohydr Res 341:138-152 (2006).
12. Carpita NC, Structure and biogenesis of the cell walls of grasses. Annu Rev Plant Physiol Plant Mol Biol 47:445-476 (1996).
13. Willför S, Sundberg A, Hemming J and Holmbom B, Polysaccharides in some industrially important softwood species. Wood Sci Technol 39:245-258 (2005).
14. Willför S, Sundberg A, Pranovich A and Holmbom B, Polysaccharides in some industrially important hardwood species. Wood Sci Technol 39:601-617 (2005).
15. Holtzapple MT and Humphrey AE, The effect of organosolv pretreatment on the enzymatic hydrolysis of poplar. Biotechnol Bioeng 26:670-676 (1984).
16. Mosier N, Wyman C, Dale B, Elander R, Lee YY, Holtzapple M et al., Features of promizing technologies for pretreatment of lignocellulosic biomass. Bioresource Technol 96:673-686 (2005).
17. Chang VS and Holtzapple MT, Fundamental factors affecting biomass enzymatic reactivity. Appl Biochem Biotechnol 84-6:5-37 (2000).
18. Pan X, Arato C, Gilkes N, Gregg D, Mabee W, Pye K et al., Biorefining of softwoods using ethanol organosolv pulping: preliminary evaluation of process streams for manufacture of fuel-grade ethanol and co-products. Biotechnol Bioeng 90:473-481 (2005).
19. Kim TH, Kim JS, Sunwoo C and Lee YY, Pretreatment of corn stover by aqueous ammonia. Bioresource Technol 90:39-47 (2003).
20. Sun Y and Cheng J, Hydrolysis of lignocellulosic materials for ethanol production: a review. Bioresource Technol 83:1-11 (2002).
21. Duff SJB and Murray WD, Bioconversion of forest products industry waste cellulosics to fuel ethanol: a review. Bioresource Technol 55:1-33 (1996).
22. Montane D, Farriol X, Salvado J, Jollez P and Chornet E, Application of steam explosion to the fractionation and rapid vapor-phase alkaline pulping of wheat straw. Biomass Bioenergy 14:261-276 (1998).
23. Mason WH, Apparatus for and process of explosion fibration of lignocellulose material. Delaware, USA, US Patent 1,655,618 (1928).
24. Galbe M and Zacchi G, A review of the production of ethanol from softwood. Appl Microbiol Biotechnol 59:618-628 (2002).
25. Kabel MA, Bos G, Zeevalking J, Voragen AG and Schols HA, Effect of pretreatment severity on xylan solubility and enzymatic breakdown of the remaining cellulose from wheat straw. Bioresource Technol 98: 2034-2042 (2007).
26. Himmel ME, Ding SY, Johnson DK, Adney WS, Nimlos MR, Brady JW et al., Biomass recalcitrance: Engineering plants and enzymes for biofuels production. Science 315:804-807 (2007).
27. Donaldson LA, Wong KKY and Mackie KL, Ultrastructure of steam-exploded wood. Wood Sci Technol 22:103-114 (1988).
28. Li J, Henriksson G and Gellerstedt G, Lignin depolymerization/repolymerization and its critical role for delignification of aspen wood by steam explosion. Bioresource Technol 98:3061-3068 (2007).
29. Ballesteros I, Negro MJ, Oliva JM, Cabanas A, Manzanares P and Ballesteros M, Ethanol production from steam-explosion pretreated wheat straw. Appl Biochem Biotechnol 129-132:496-508 (2006).
30. Varga E, Réczey K and Zacchi G, Optimization of steam pretreatment of corn stover to enhance enzymatic digestibility. Appl Biochem Biotechnol 113-116:509-523 (2004).
31. Sassner P, Galbe M and Zacchi G, Bioethanol production based on simultaneous saccharification and fermentation of steam-pretreated Salix at high dry-matter content. Enzyme Microb Technol 39:756-762 (2006).
32. Clark TA, Mackie KL, Dare PH and McDonald AG, Steam explosion of the softwood Pinus radiata with sulphur dioxide addition. J Wood Chem Technol 9:135-166 (1989).
33. Stenberg K, Tengborg C, Galbe M and Zacchi G, Optimization of steam pretreatment of SO2-impregnated mixed softwoods for ethanol production. J Chem Technol Biotechnol 71:299-308 (1998).
34. Tengborg C, Stenberg K, Galbe M, Zacchi G, Larsson S, Palmqvist E et al., Comparison of SO2 and H2SO4 impregnation of softwood prior to steam pretreatment on ethanol production. Appl Biochem Biotechnol 70-72:3-15 (1998).
35. Lloyd TA and Wyman CE, Combined sugar yields for dilute sulfuric acid pretreatment of corn stover followed by enzymatic hydrolysis of the remaining solids. Bioresource Technol 96:1967-1977 (2005).
36. Schell DJ, Riley CJ, Dowe N, Farmer J, Ibsen KN, Ruth MF et al., A bioethanol process development unit: initial operating experiences and results with a corn fiber feedstock. Bioresource Technol 91:179-188 (2004).
37. Lee YY, Iyer P and Torget RW, Dilute-acid hydrolysis of lignocellulosic biomass. Adv Biochem Eng Biotechnol 65:93-115 (1999).
38. Schmidt AS and Thomsen AB, Optimization of wet oxidation pretreatment of wheat straw. Bioresource Technol 64:139-151 (1998).
39. Palonen H, Thomsen AB, Tenkanen M, Schmidt AS and Viikari L, Evaluation of wet oxidation pretreatment for enzymatic hydrolysis of softwood. Appl Biochem Biotechnol 117:1-17 (2004).
40. Varga E, Klinke HB, Réczey K and Thomsen AB, High solid simultaneous saccharification and fermentation of wet oxidized corn stover to ethanol. Biotechnol Bioeng 88:567-574 (2004).
41. Martin C, González Y, Fernández T and Thomsen AB, Investigation of cellulose convertibility and ethanolic fermentation of sugarcane bagasse pretreated by wet oxidation and steam explosion. J Chem Technol Biotechnol 81:1669-1677 (2006).
42. Klinke HB, Ahring BK, Schmidt AS and Thomsen AB, Characterization of degradation products from alkaline wet oxidation of wheat straw. Bioresource Technol 82:15-26 (2002).
43. Ahring BK and Munck J, Method for treating biomass and organic waste with the purpose of generating desired biologically based products. Denmark, Patent WO 2006/032282 A1 (2006).
44. Gollapalli LE, Dale BE and Rivers DM, Predicting digestibility of ammonia fiber explosion (AFEX)-treated rice straw. Appl Biochem Biotechnol 98:23-35 (2002).
45. Chundawat SPS, Venkatesh B and Dale BE, Effect of particle size based separation of milled corn stover on AFEX pretreatment and enzymatic digestibility. Biotechnol Bioeng 96:219-231 (2007).
46. Alizadeh H, Teymouri F, Gilbert TI and Dale BE, Pretreatment of switchgrass by ammonia fiber explosion (AFEX). Appl Biochem Biotechnol 121:1133-1141 (2005).
47. Teymouri F, Laureano-Perez L, Alizadeh H and Dale BE, Optimization of the ammonia fiber explosion (AFEX) treatment parameters for enzymatic hydrolysis of corn stover. Bioresource Technol 96:2014-2018 (2005).
48. Pan XJ, Gilkes N, Kadla J, Pye K, Saka S, Gregg D et al., Bioconversion of hybrid poplar to ethanol and co-products using an organosolv fractionation process: Optimization of process yields. Biotechnol Bioeng 94:851-861 (2006).
49. Kurabi A, Berlin A, Gilkes N, Kilburn D, Bura R, Robinson J et al., Enzymatic hydrolysis of steam-exploded and ethanol organosolv- pretreated Douglas-Fir by novel and commercial fungal-cellulases. Appl Biochem Biotechnol 121:219-230 (2005).
50. Farrell AE, Plevin RJ, Turner BT, Jones AD, O'Hare M and Kammen DM, Ethanol can contribute to energy and environmental goals. Science 311:506-508 (2006).
51. Schell DJ and Harwood C, Milling of lignocellulosic biomass - results of pilot-scale testing. Appl Biochem Biotechnol 45-6:159-168 (1994).
52. Zhu SD, Wu YX, Yu ZN, Chen QM, Wu GY, Yu FQ et al., Microwave- assisted alkali pre-treatment of wheat straw and its enzymatic hydrolysis. Biosyst Eng 94:437-442 (2006).
53. Jeffries TW, Engineering yeasts for xylose metabolism. Curr Opin Biotechnol 17:320-326 (2006).
54. Schubert C, Can biofuels finally take center stage? Nat Biotechnol 24:777-784 (2006).
55. Zhang YHP, Himmel ME and Mielenz JR, Outlook for cellulase improvement: Screening and selection strategies. Biotehcnol Adv 24:452-481 (2006).
56. Eriksson T, Karlsson J and Tjerneld F, A model explaining declining rate in hydrolysis of lignocellulose substrates with cellobiohydrolase I (Cel7A) and endoglucanase I (Cel7B) of Trichoderma reesei. Appl Biochem Biotechnol 101:41-60 (2002).
57. Väljamäe P, Kipper K, Pettersson G and Johansson G, Synergistic cellulose hydrolysis can be described in terms of fractal-like kinetics. Biotechnol Bioeng 84:254-257 (2003).
58. Beg QK, Kapoor M, Mahajan L and Hoondal GS, Microbial xylanases and their industrial applications: a review. Appl Microbiol Biotechnol 56: 326-338 (2001).
59. Shallom D and Shoham Y, Microbial hemicellulases. Curr Opin Microbiol 6:219-228 (2003).
60. Wood TM, Properties of cellulolytic enzyme systems. Biochem Soc Trans 13:407-410 (1985).
61. Foreman PK, Brown D, Dankmeyer L, Dean R, Diener S, Dunn-Coleman NS et al., Transcriptional regulation of biomass-degrading enzymes in the filamentous fungus Trichoderma reesei. J Biol Chem 278: 31988-31997 (2003).
62. Henrissat B, A classification of glycosyl hydrolases based on amino acid sequence similarities. Biochem J 280:309-316 (1991).
63. Henrissat B, Teeri TT and Warren RA, A scheme for designating enzymes that hydrolyse the polysaccharides in the cell walls of plants. FEBS Lett 425:352-354 (1998).
64. Coutinho PM and Henrissat B, Carbohydrate-active enzymes: An integrated database approach. Special Publications of the Royal Society of Chemistry 246:3-14 (1999).
65. Boraston AB, Bolam DN, Gilbert HJ and Davies GJ, Carbohydrate-binding modules: fine-tuning polysaccharide recognition. Biochem J 382:769-781 (2004).
66. Wang LS, Liu J, Zhang YZ, Zhao Y and Gao PJ, Comparison of domains function between cellobiohydrolase I and endoglucanase I from Trichoderma pseudokoningii S-38 by limited proteolysis. J Mol Catal B 24-5:27-38 (2003).
67. Suurnäkki A, Tenkanen M, Siika-Aho M, Niku-Paavola M-L, Viikari L and Buchert J, Trichoderma reesei cellulases and their core domains in the hydrolysis and modification of chemical pulp. Cellulose 7:189-209 (2000).
68. Yun SI, Jeong CS, Chung DK and Choi HS, Purification and some properties of a beta-glucosidase from Trichoderma harzianum type C-4. Biosci Biotechnol Biochem 65:2028-2032 (2001).
69. Decker CH, Visser J and Schreier P, β-glucosidases from five black Aspergillus species: study of their physico-chemical and biocatalytic properties. J Agric Food Chem 48:4929-4936 (2000).
70. Holtzapple M, Cognata M, Shu Y and Hendrickson C, Inhibition of Trichoderma reesei cellulase by sugars and solvents. Biotechnol Bioeng 36:275-287 (1990).
71. Tolan JS and Foody B, Cellulases from submerged fermentation. Adv Biochem Eng Biotechnol 65:41-67 (1999).
72. Xiao ZZ, Zhang X, Gregg DJ and Saddler JN, Effects of sugar inhibition on cellulases and beta-glucosidase during enzymatic hydrolysis of softwood substrates. Appl Biochem Biotechnol 113-16:1115-1126 (2004).
73. Saha BC and Bothast RJ, Production, purification, and characterization of a highly glucose-tolerant novel beta-glucosidase from Candida peltata. Appl Environ Microbiol 62:3165-3170 (1996).
74. Tengborg C, Galbe M and Zacchi G, Reduced inhibition of enzymatic hydrolysis of steam-pretreated softwood. Enzyme Microb Technol 28:835-844 (2001).
75. Panagiotou G and Olsson L, Effect of compounds released during pretreatment of wheat straw on microbial growth and enzymatic hydrolysis rates. Biotechnol Bioeng 96:250-258 (2007).
76. Cantarella M, Cantarella L, Gallifuoco A, Spera A and Alfani F, Effect of inhibitors released during steam-explosion treatment of poplar wood on subsequent enzymatic hydrolysis and SSF. Biotechnol Prog 20:200-206 (2004).
77. Alfani F, Gallifuoco A, Saporosi A, Spera A and Cantarella M, Comparison of SHF and SSF processes for the bioconversion of steam-exploded wheat straw. J Ind Microbiol Biotechnol 25:184-192 (2000).
78. Wingren A, Galbe M and Zacchi G, Techno-economic evaluation of producing ethanol from softwood: comparison of SSF and SHF and identification of bottlenecks. Biotechnol Prog 19:1109-1117 (2003).
79. Chen H and Jin S, Effect of ethanol and yeast on cellulase activity and hydrolysis of crystalline cellulose. Enzyme Microb Technol 39:1430-1432 (2006).
80. Moldes AB, Alonso JL and Parajo JC, Strategies to improve the bioconversion of processed wood into lactic acid by simultaneous saccharification and fermentation. J Chem Technol Biotechnol 76:279-284 (2001).
81. Gan Q, Allen SJ and Taylor G, Design and operation of an integrated membrane reactor for enzymatic cellulose hydrolysis. Biochem Eng J 12:223-229 (2002).
82. Belafi-Bako K, Koutinas A, Nemestothy N, Gubicza L and Webb C, Continuous enzymatic cellulose hydrolysis in a tubular membrane bioreactor. Enzyme Microb Technol 38:155-161 (2006).
83. Mameri N, Hamdache F, Abdi N, Belhocine D, Grib H, Lounici H et al., Enzymatic saccharification of olive mill solid residue in a membrane reactor. J Membrane Sci 178:121-130 (2000).
84. Yang S, Ding WY and Chen HZ, Enzymatic hydrolysis of rice straw in a tubular reactor coupled with UF membrane. Proc Biochem 41:721-725 (2006).
85. Mohagheghi A, Tucker M, Grohmann K and Wyman C, High solids simultaneous saccharification and fermentation of pretreated wheat straw to ethanol. Appl Biochem Biotechnol 33:67-81 (1992).
86. Fan ZL, South C, Lyford K, Munsie J, van Walsum P and Lynd LR, Conversion of paper sludge to ethanol in a semicontinuous solids-fed reactor. Bioprocess Biosyst Eng 26:93-101 (2003).
87. Fan ZL and Lynd LR, Conversion of paper sludge to ethanol. I: Impact of feeding frequency and mixing energy characterization. Bioprocess Biosyst Eng 30:27-34 (2007).
88. Tolan JS, Iogeńs process for producing ethanol from cellulosic biomass. Clean Technol Environ Policy 3:339-345 (2002).
89. Jørgensen H, Vibe-Pedersen J, Larsen J and Felby C, Liquefaction of lignocellulose at high-solids concentrations. Biotechnol Bioeng 96:862-870 (2007).
90. Rudolf A, Alkasrawi M, Zacchi G and Liden G, A comparison between batch and fed-batch simultaneous saccharification and fermentation of steam pretreated spruce. Enzyme Microb Technol 37:195-204 (2005).
91. Berlin A, Gilkes N, Kilburn D, Maximenko V, Bura R, Markov A et al., Evaluation of cellulase preparations for hydrolysis of hardwood substrates. Appl Biochem Biotechnol 129-132:528-545 (2006).
92. Berlin A, Gilkes N, Kilburn D, Bura R, Markov A, Skomarovsky A et al., Evaluation of novel fungal cellulase preparations for ability to hydrolyze softwood substrates - evidence for the role of accessory enzymes. Enzyme Microb Technol 37:175-184 (2005).
93. Jørgensen H and Olsson L, Production of cellulases by Penicillium brasilianum IBT 20888 - Effect of substrate on hydrolytic performance. Enzyme Microb Technol 38:381-390 (2006).
94. Baker JO, Vinzant TB, Ehrman CI, Adney WS and Himmel ME, Use of a new membrane-reactor saccharification assay to evaluate the performance of cellulases under simulated SSF conditions. Appl Biochem Biotechnol 63-65:585-595 (1997).
95. McMillan JD, Dowe N, Mohagheghi A and Newman MM, Assessing the efficacy of cellulase enzyme preparations under simultaneous saccharification and fermentation processing conditions, in Glycosyl Hydrolases for Biomass Conversion, ed. by Himmel ME, Baker JO and Saddler JN. American Chemical Society, Washington DC, pp. 144-166 (2001).
96. Himmel ME, Ruth MF and Wyman CE, Cellulase for commodity products from cellulosic biomass. Curr Opin Biotechnol 10:358-364 (1999).
97. Lynd LR, van Zyl WH, McBride JE and Laser M, Consolidated bioprocessing of cellulosic biomass: an update. Curr Opin Biotechnol 16:577-583 (2005).
98. Lu YP, Zhang YHP and Lynd LR, Enzyme-microbe synergy during cellulose hydrolysis by Clostridium thermocellum. Proc Natl Acad Sci USA 103:16165-16169 (2006).
99. Berlin A, Maximenko V, Gilkes N and Saddler J, Optimization of enzyme complexes for lignocellulose hydrolysis. Biotechnol Bioeng 97:287-296 (2007).
100. Sørensen HR, Pedersen S, Jørgensen CT and Meyer AS, Enzymatic hydrolysis of wheat arabinoxylan by a recombinant "minimal" enzyme cocktail containing β-xylosidase and novel endo-1,4-β-xylanase and α−L-arabinofuranosidase activities. Biotechnol Prog 23:100-107 (2007).
101. Dien BS, Li XL, Iten LB, Jordan DB, O'Bryan PJ and Cotta MA, Enzymatic saccharification of hot-water pretreated corn fiber for production of monosaccharides. Enzyme Microb Technol 39:1137-1144 (2006).
102. Cosgrove DJ, Loosening of plant cell walls by expansins. Nature 407:321-326 (2000).
103. Saloheimo M, Paloheimo M, Hakola S, Pere J, Swanson B, Nyyssonen E et al., Swollenin, a Trichoderma reesei protein with sequence similarity to the plant expansins, exhibits disruption activity on cellulosic materials. Eur J Biochem 269:4202-4211 (2002).
104. Mansfield SD, Mooney C and Saddler JN, Substrate and enzyme characteristics that limit cellulose hydrolysis. Biotechnol Prog 15: 804-816 (1999).
105. Berlin A, Balakshin M, Gilkes N, Kadla J, Maximenko V, Kubo S et al., Inhibition of cellulase, xylanase and beta-glucosidase activities by softwood lignin preparations. J Biotechnol 125, 198-209 (2006).
106. Eriksson T, Börjesson J and Tjerneld F, Mechanism of surfactant effect in enzymatic hydrolysis of lignocellulose. Enzyme Microb Technol 31:353-364 (2002).
107. Sewalt VJH, Glasser WG and 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 45:1823-1828 (1997).
108. Lu Y, Yang B, Gregg D, Saddler JN and Mansfield SD, Cellulase adsorption and an evaluation of enzyme recycle during hydrolysis of steam-exploded softwood residues. Appl Biochem Biotechnol 98-100:641-654 (2002).
109. Berlin A, Gilkes N, Kurabi A, Bura R, Tu MB, Kilburn D et al., Weak lignin-binding enzymes - A novel approach to improve activity of cellulases for hydrolysis of lignocellulosics. Appl Biochem Biotechnol 121:163-170 (2005).
110. Palonen H, Tjerneld F, Zacchi G and Tenkanen M, Adsorption of Trichoderma reesei CBH I and EG II and their catalytic domains on steam pretreated softwood and isolated lignin. J Biotechnol 107:65-72 (2004).
111. Yang B, Boussaid A, Mansfield SD, Gregg DJ and Saddler JN, Fast and efficient alkaline peroxide treatment to enhance the enzymatic digestibility of steam-exploded softwood substrates. Biotechnol Bioeng 77:678-684 (2002).
112. Yang B and Wyman C, BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates. Biotechnol Bioeng 94: 611-617 (2006).
113. Kristensen JB, Börjesson J, Bruun MH, Tjerneld F and Jørgensen H, Use of surface active additives in enzymatic hydrolysis of wheat straw lignocellulose. Enzyme Microb Technol 40:888-895 (2007).
114. Börjesson J, Petersson R and Tjerneld F, Enhanced enzymatic conversion of softwood lignocellulose by poly(ethylene gycol) addition. Enzyme Microb Technol 40:754-762 (2007).
115. Börjesson J, Engqvist M, Sipos B and Tjerneld F, Effect of poly(ethylene glycol) on enzymatic hydrolysis and adsorption of cellulase enzymes to pretreated lignocellulose. Enzyme Microb Technol, 41:186-195 (2007).
116. Singh A, Kumar PKR and Schügerl K, Adsorption and reuse of cellulases during saccharification of cellulosic materials. J Biotechnol 19:205-212 (1991).
117. Ramos LP, Breuil C and Saddler JN, The use of enzyme recycling and the influence of sugar accumulation on the cellulose hydrolysis by Trichoderma cellulases. Enzyme Microb Technol 15:19-25 (1993).
118. Gregg DJ, Boussaid A and Saddler JN, Techno-economic evaluations of a gerneric wood-to-ethanol process: Effect of increased cellulose yields and enzyme recycle. Bioresource Technol 63:7-12 (1998).
119. Lee D, Yu AHC and Saddler JN, Evaluation of cellulase recycling strategies for the hydrolysis of lignocellulosic substrates. Biotechnol Bioeng 45:328-336 (1995).
120. Ryu DDY and Mandels M, Cellulases: biosynthesis and applications. Enzyme Microb Technol 2:91-102 (1980).
121. Castellanos OF, Sinitsyn AP and Vlasenko EY, Comparative evaluation of hydrolytic efficiency toward microcrystalline cellulose of Penicillium and Trichoderma cellulases. Bioresource Technol 52:119-124 (1995).
122. Yu AHC, Lee D and Saddler JN, Adsorption and desorption of cellulose components during the hydrolysis of a steam-exploded birch substrate. Biotechnol Appl Biochem 21:203-216 (1995).
123. Tu MB, Chandra RP and Saddler JN, Evaluating the distribution of cellulases and the recycling of free cellulases during the hydrolysis of lignocellulosic substrates. Biotechnol Prog 23:398-406 (2007).
124. Dourado F, Bastos M, Mota M and Gama FM, Studies on the properties of Celluclast/Eudragit L-100 conjugate. J Biotechnol 99:121-131 (2002).
125. Garcia A, Oh S and Engler CR, Cellulase immobilization on Fe3O4 and characterization. Biotechnol Bioeng 33:321-326 (1989).
126. Gaur R, Lata and Khare SK, Immobilization of xylan-degrading enzymes from Scytalidium thermophilum on Eudragit L-100. World J Microbiol Biotechnol 21:1123-1128 (2005).
127. Fujishima S, Yaku F and Koshijima T, Immobilization of beta-glucosidase using wood residue for enzymatic-hydrolysis. J Carbohydr Chem 10:671-680 (1991).
128. Yuan XY, Shen NX, Sheng J and Wei X, Immobilization of cellulase using acrylamide grafted acrylonitrile copolymer membranes. J Membrane Sci 155:101-106 (1999).
129. Tu M, Zhang X, Kurabi A, Gilkes N, Mabee W and Saddler J, Immobilization of beta-glucosidase on Eupergit C for lignocellulose hydrolysis. Biotechnol Lett 28:151-156 (2006).
130. Saville BA, Khavkine M, Seetharam G, Marandi B and Zuo YL, Characterization and performance of immobilized amylase and cellulase. Appl Biochem Biotechnol 113-16:251-259 (2004).
131. Tu M, Zhang X, Kurabi A, Gilkes N, Mabee W and Saddler J, Immobilization of beta-glucosidase on Eupergit C for lignocellulose hydrolysis. Biotechnol Lett 28:151-156 (2006).
132. Wyman CE, Dale BE, Elander RT, Holtzapple M, Ladisch MR and Lee YY, Comparative sugar recovery data from laboratory scale application of leading pretreatment technologies to corn stover. Bioresource Technol 96:2026-2032 (2005).
133. Eggeman T and Elander RT, Process and economic analysis of pretreatment technologies. Bioresource Technol 96:2019-2025 (2005).
134. Sasaki M, Kabyemela B, Malaluan R, Hirose S, Takeda N, Adschiri T et al., Cellulose hydrolysis in subcritical and supercritical water. J Supercrit Fluids 13:261-268 (1998).
135. Feng W, van der Kooi HJ and Arons JDS, Biomass conversions in subcritical and supercritical water: driving force, phase equilibria, and thermodynamic analysis. Chem Eng Process 43:1459-1467 (2004).
136. Hayn M, Steiner W, Klinger R, Steinmüller H, Sinner M and Esterbauer H, Basic research and pilot studies on the enzymatic conversion of lignocellulosics, in Bioconversion of Forest and Agricultural Plant Residues, ed. by Saddler JN.CAB International, Wallingford, pp. 33-72 (1993).
137. Wiselogel A, Tyson J and Johnsson D, Biomass feedstock resources and composition, in Handbook on Bioethanol: Production and Utilization, ed. by Wyman CE.Taylor & Francis, Washington, pp. 105-118 (1996).