Comparison of enzymatic reactivity of corn stover solids prepared by dilute acid, AFEX™, and ionic liquid pretreatments

Biotechnology for Biofuels

Xiadi Gao¹  Rajeev Kumar¹  Seema Singh²  Blake A Simmons²  Venkatesh Balan³  Bruce E Dale³  Charles E Wyman¹ 

[1] Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, CA 92507, USA

[2] Sandia National Laboratories, Livermore, CA 94551, USA

[3] Biomass Conversion Research Laboratory, Department of Chemical Engineering and Materials Science, Michigan State University, 3815 Technology Boulevard, MBI Building, Lansing, MI 48910, USA

关键词: Hydrolysis;    Pretreatment;    Oligomers;    Cellulase;    Enzyme adsorption;    Corn stover;   

Others  :  792486
DOI  :  10.1186/1754-6834-7-71

 received in 2012-11-27, accepted in 2014-02-20,  发布年份 2014

【 摘 要 】

Background

Pretreatment is essential to realize high product yields from biological conversion of naturally recalcitrant cellulosic biomass, with thermochemical pretreatments often favored for cost and performance. In this study, enzymatic digestion of solids from dilute sulfuric acid (DA), ammonia fiber expansion (AFEX™), and ionic liquid (IL) thermochemical pretreatments of corn stover were followed over time for the same range of total enzyme protein loadings to provide comparative data on glucose and xylose yields of monomers and oligomers from the pretreated solids. The composition of pretreated solids and enzyme adsorption on each substrate were also measured to determine. The extent glucose release could be related to these features.

Results

Corn stover solids from pretreatment by DA, AFEX, and IL were enzymatically digested over a range of low to moderate loadings of commercial cellulase, xylanase, and pectinase enzyme mixtures, the proportions of which had been previously optimized for each pretreatment. Avicel® cellulose, regenerated amorphous cellulose (RAC), and beechwood xylan were also subjected to enzymatic hydrolysis as controls. Yields of glucose and xylose and their oligomers were followed for times up to 120 hours, and enzyme adsorption was measured. IL pretreated corn stover displayed the highest initial glucose yields at all enzyme loadings and the highest final yield for a low enzyme loading of 3 mg protein/g glucan in the raw material. However, increasing the enzyme loading to 12 mg/g glucan or more resulted in DA pretreated corn stover attaining the highest longer-term glucose yields. Hydrolyzate from AFEX pretreated corn stover had the highest proportion of xylooligomers, while IL produced the most glucooligomers. However, the amounts of both oligomers dropped with increasing enzyme loadings and hydrolysis times. IL pretreated corn stover had the highest enzyme adsorption capacity.

Conclusions

Initial hydrolysis yields were highest for substrates with greater lignin removal, a greater degree of change in cellulose crystallinity, and high enzyme accessibility. Final glucose yields could not be clearly related to concentrations of xylooligomers released from xylan during hydrolysis. Overall, none of these factors could completely account for differences in enzymatic digestion performance of solids produced by AFEX, DA, and IL pretreatments.

【 授权许可】

   
2014 Gao et al.; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Wyman CE, Dale BE, Elander RT, Holtzapple M, Ladisch MR, Lee YY: Coordinated development of leading biomass pretreatment technologies. Bioresour Technol 2005, 96:1959-1966.
• [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]Kamm B, Kamm M: Principles of biorefineries. Appl Microbiol Biotechnol 2004, 64:137-145.
• [4]Jorgensen H, Kristensen JB, Felby C: Enzymatic conversion of lignocellulose into fermentable sugars: challenges and opportunities. Biofuel Bioprod Bioresour 2007, 1:119-134.
• [5]Ragauskas AJ, Williams CK, Davison BH, Britovsek G, Cairney J, Eckert CA, Frederick WJ Jr, Hallett JP, Leak DJ, Liotta CL, Mielenz JR, Murphy R, Templer R, Tschaplinski T: The path forward for biofuels and biomaterials. Science 2006, 311:484-489.
• [6]Henrissat B: Celluases and their interaction with cellulose. Cellulose 1994, 1:169-196.
• [7]Lynd LR, Weimer PJ, van Zyl WH, Pretorius IS: Microbial cellulose utilization: fundamentals and biotechnology. Microbiol Mol Biol Rev 2002, 66:506-739.
• [8]Zhang YHP, Lynd LR: Toward an aggregated understanding of enzymatic hydrolysis of cellulose: noncomplexed cellulase systems. Biotechnol Bioeng 2004, 88:797-824.
• [9]Bansal P, Hall M, Realff MJ, Lee JH, Bommarius AS: Modeling cellulase kinetics on lignocellulosic substrates. Biotechnol Adv 2009, 27:833-848.
• [10]Kumar R, Wyman CE: Effects of cellulase and xylanase enzymes on the deconstruction of solids from pretreatment of poplar by leading technologies. Biotechnol Prog 2009, 25:302-314.
• [11]Mosier N, Wyman C, Dale B, Elander R, Lee YY, Holtzapple M, Ladisch M: Features of promising technologies for pretreatment of lignocellulosic biomass. Bioresour Technol 2005, 96:673-686.
• [12]Yang B, Wyman CE: Pretreatment: the key to unlocking low-cost cellulosic ethanol. Biofuel Bioprod Bioresour 2008, 2:26-40.
• [13]Hsu TA: Pretreatment of biomass. In Handbook on Bioethonal Production and Utilization. Edited by Wyman CE. Washington, DC: Taylor & Francis; 1996.
• [14]Hu F, Ragauskas A: Pretreatment and lignocellulosic chemistry. Bioenergy Res 2012, 5:1043-1066.
• [15]Knappert D, Grethlein H, Converse A: Partial acid hydrolysis of poplar wood as a pretreatment for enzymatic-hydrolysis. Biotechnol Bioeng 1981, 11:67-77.
• [16]Yang B, Wyman CE: Effect of xylan and lignin removal by batch and flowthrough pretreatment on the enzymatic digestibility of corn stover cellulose. Biotechnol Bioeng 2004, 86:88-95.
• [17]Ohgren K, Bura R, Saddler J, Zacchi G: Effect of hemicellulose and lignin removal on enzymatic hydrolysis of steam pretreated corn stover. Bioresour Technol 2007, 98:2503-2510.
• [18]Dale BE, Moreira MJ: A freeze-explosion technique for increasing cellulose hydrolysis. Biotechnol Bioeng 1982, 12:31-43.
• [19]Holtzapple MT, Jun JH, Ashok G, Patibandla SL, Dale BE: The ammonia freeze explosion (AFEX) process. Appl Biochem Biotechnol 1991, 28–9:59-74.
• [20]Dale BE, Henk LE, Shiang M: Fermentation of lignocellulosic materials treated by ammonia freeze-explosion. Dev Ind Microbiol 1985, 26:223-234.
• [21]Swatloski RP, Spear SK, Holbrey JD, Rogers RD: Dissolution of cellose with ionic liquids. J Am Chem Soc 2002, 124:4974-4975.
• [22]Cheng G, Varanasi P, Li C, Liu H, Menichenko YB, Simmons BA, Kent MS, Singh S: Transition of cellulose crystalline structure and surface morphology of biomass as a function of ionic liquid pretreatment and its relation to enzymatic hydrolysis. Biomacromolecules 2011, 12:933-941.
• [23]Dadi AP, Schall CA, Varanasi S: Mitigation of cellulose recalcitrance to enzymatic hydrolysis by ionic liquid pretreatment. Appl Biochem Biotechnol 2007, 137–140:407-421.
• [24]Zhao H, Jones CL, Baker GA, Xia S, Olubajo O, Person VN: Regenerating cellulose from ionic liquids for an accelerated enzymatic hydrolysis. J Biotechnol 2009, 139:47-54.
• [25]Michalowicz G, Toussaint B, Vignon MR: Ultrastructural changes in poplar cell-wall during steam explosion treatment. Holzforschung 1991, 45:175-179.
• [26]Grethlein HE: Pretreatment for enhanced hydrolysis of cellulosic biomass. Biotechnol Adv 1984, 2:43-62.
• [27]Clark TA, Mackie KL, Dare PH, McDonald AG: Steam explosion of the softwood Pinus radiata with sulfur dioxide addition. 2. process characterization. J Wood Chem Tech 1989, 9:135-166.
• [28]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.
• [29]Selig MJ, Viamajala S, Decker SR, Tucker MP, Himmel ME, Vinzant TB: Deposition of lignin droplets produced during dilute acid pretreatment of maize stems retards enzymatic hydrolysis of cellulose. Biotechnol Prog 2007, 23:1333-1339.
• [30]Grous WR, Converse AO, Grethlein HE: Effect of steam explosion pretreatment of pore size and enzymatic-hydrolysis of poplar. Enzyme Microb Technol 1986, 8:274-280.
• [31]Kumar R, Mago G, Balan V, Wyman CE: Physical and chemical characterizations of corn stover and poplar solids resulting from leading pretreatment technologies. Bioresour Technol 2009, 100:3948-3962.
• [32]Chundawat SPS, Bellesia G, Uppugundla N, Sousa LC, Gao D, Cheh AM, Agarwal UP, Bianchetti CM, Phillips GN Jr, Langan P, Balan V, Gnanakaran S, Dale BE: Restructuring the crystalline cellulose hydrogen bond network enhances its depolymerization rate. J Am Chem Soc 2011, 133:11163-11174.
• [33]Chundawat SPS, Donohoe BS, Sousa LC, Elder T, Agarwal UP, Lu F, Ralph J, Himmel ME, Balan V, Dale BE: Multi-scale visualization and characterization of lignocellulosic plant cell wall deconstruction during thermochemical pretreatment. Energy Environ Sci 2011, 4:973-984.
• [34]Arora R, Manisseri C, Li C, Ong M, Scheller H, Vogel K, Simmons B, Singh S: Monitoring and analyzing process streams towards understanding ionic liquid pretreatment of switchgrass (Panicum virgatum L.). Bioenergy Res 2010, 3:134-145.
• [35]Wyman CE, Dale BE, Elander RT, Holtzapple M, Ladisch MR, Lee YY: Comparative sugar recovery data from laboratory scale application of leading pretreatment technologies to corn stover. Bioresour Technol 2005, 96:2026-2032.
• [36]Li C, Knierim B, Manisseri C, Arora R, Scheller HV, Auer M, Vogel KP, Simmons BA, Singh S: Comparison of dilute acid and ionic liquid pretreatment of switchgrass: biomass recalcitrance, delignification and enzymatic saccharification. Bioresour Technol 2010, 101:4900-4906.
• [37]Shi J, Ebrik MA, Yang B, Garlock RJ, Balan V, Dale BE, Pallapolu VR, Lee YY, Kim Y, Mosier NS, Ladisch MR, Holtzapple MT, Falls M, Sierra-Ramirez R, Donohoe BS, Vinzant TB, Elander RT, Hames B, Thomas S, Warner RE, Wyman CE: Application of cellulase and hemicellulase to pure xylan, pure cellulose, and switchgrass solids from leading pretreatments. Bioresour Technol 2011, 102:11080-11088.
• [38]Selig M, Weiss N, Ji Y: Enzymatic Saccharification of Lignocellulosic Biomass. Golden, CO: National Renewable Energy Laboratory; 2008. [Technical Report NREL/TP-510-42629]
• [39]Chundawat SPS, Balan V, Dale BE: High-throughput microplate technique for enzymatic hydrolysis of lignocellulosic Biomass. Biotechnol Bioeng 2008, 99:1281-1294.
• [40]Hu J, Arantes V, Saddler J: The enhancement of enzymatic hydrolysis of lignocellulosic substrates by the addition of accessory enzymes such as xylanase: is it an additive or synergistic effect? Biotechnol Biofuels 2011, 4:36. BioMed Central Full Text
• [41]Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D: Determination of Sugars, Byproducts, and Degradation Products in Liquid Fraction Process Samples. Golden, CO: National Renewable Energy Laboratory; 2008. [Technical Report NREL/TP-510-42623]
• [42]Jeoh T, Ishizawa CI, Davis MF, Himmel ME, Adney WS, Johnson DK: Cellulase digestibility of pretreated biomass is limited by cellulose accessibility. Biotechnol Bioeng 2007, 98:112-122.
• [43]Kumar R, Wyman CE: Effect of enzyme supplementation at moderate cellulase loadings on initial glucose and xylose release from corn stover solids pretreated by leading technologies. Biotechnol Bioeng 2009, 102:457-467.
• [44]Qing Q, Yang B, Wyman CE: Xylooligomers are strong inhibitors of cellulose hydrolysis by enzymes. Bioresour Technol 2010, 101:9624-9630.
• [45]Qing Q, Wyman CE: Supplementation with xylanase and beta-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover. Biotechnol Biofuels 2011, 4:18. BioMed Central Full Text
• [46]Chang V, Holtzapple M: Fundamental factors affecting biomass enzymatic reactivity. Appl Biochem Biotechnol 2000, 84–86:5-37.
• [47]Kumar R, Wyman CE: Cellulase adsorption and relationship to features of corn stover solids produced by leading pretreatments. Biotechnol Bioeng 2009, 103:252-267.
• [48]Zhang YHP, Cui JB, Lynd LR, Kuang LR: A transition from cellulose swelling to cellulose dissolution by o-phosphoric acid: evidence from enzymatic hydrolysis and supramolecular structure. Biomacromolecules 2006, 7:644-648.
• [49]Zhang S, Wolfgang DE, Wilson DB: Substrate heterogeneity causes the nonlinear kinetics of insoluble cellulose hydrolysis. Biotechnol Bioeng 1999, 66:35-41.
• [50]Singh S, Simmons BA, Vogel KP: Visualization of biomass solubilization and cellulose regeneration during ionic liquid pretreatment of switchgrass. Biotechnol Bioeng 2009, 104:68-75.
• [51]Stahlberg J, Johansson G, Pettersson G: A new model for enzymatic-hydrolysis of cellulose based on the two-domain structure of cellobiohydrolyase I. Nat Biotechnol 1991, 9:286-290.
• [52]Rollin JA, Zhu Z, Sathitsuksanoh N, Zhang YHP: Increasing cellulose accessibility is more important than removing lignin: a comparison of cellulose solvent-based lignocellulose fractionation and soaking in aqueous ammonia. Biotechnol Bioeng 2011, 108:22-30.
• [53]Kumar R, Wyman CE: Physical and chemical features of pretreated biomass that influence macro-/micro-accessibility and biological processing. In Aqueous Pretreatment of Plant Biomass for Biological and Chemical Conversion to Fuels and Chemicals. Edited by Wyman CE. Chichester: John Wiley & Sons Ltd; 2013:281-310.
• [54]Arantes V, Saddler J: Cellulose accessibility limits the effectiveness of minimum cellulase loading on the efficient hydrolysis of pretreated lignocellulosic substrates. Biotechnol Biofuels 2011, 4:3. BioMed Central Full Text
• [55]Kotiranta P, Karlsson J, Siika-aho M, Medve J, Viikari L, Tjerneld F, Tenkanen M: Adsorption and activity of Trichoderma reesei cellobiohydrolase I, endoglucanase II, and the corresponding core proteins on steam pretreated willow. Appl Biochem Biotechnol 1999, 81:81-90.
• [56]Lou H, Zhu JY, Lan TQ, Lai H, Qiu X: pH-Induced lignin surface modification to reduce nonspecific cellulase binding and enhance enzymatic saccharification of lignocelluloses. ChemSusChem 2013, 6:919-927.
• [57]Kumar R, Wyman CE: Access of cellulase to cellulose and lignin for poplar solids produced by leading pretreatment technologies. Biotechnol Prog 2009, 25:807-819.
• [58]Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D, Crocker D: Determination of Structural Carbohydrates and Lignin in Biomass. Golden, CO: National Renewable Energy Laboratory; 2011. [Technical Report NREL/TP-510-42618]
• [59]Association of Official Analytical Chemists (AOAC): Protein (crude) determination in animal feed: copper catalyst Kjeldahl method (984.13). In Official Methods of Analysis. 15th edition. Gaithersburg, MD: AOAC International; 1990.
• [60]Kumar R, Wyman CE: An improved method to directly estimate cellulase adsorption on biomass solids. Enzyme Microb Technol 2008, 42:426-433.
• [61]Sluiter A, Hames B, Hyman D, Payne C, Ruiz R, Scarlata C, Sluiter J, Templeton D, Wolfe J: Determination of Total Solids in Biomass and Total Dissolved Solids in Liquid Process Samples. Golden, CO: National Renewable Energy Laboratory; 2008. [Technical Report NREL/TP-510-42621]
• [62]DeMartini JD, Studer MH, Wyman CE: Small-scale and automatable high-throughput compositional analysis of biomass. Biotechnol Bioeng 2011, 108:306-312.
• [63]Beldman G, Voragen AGJ, Rombouts FM, Searlevanleeuwen MF, Pilnik W: Adsorption and kinetic-behavior of purified endoglucanases and exoglucanases from Trichoderma viride. Biotechnol Bioeng 1987, 30:251-257.