Recent updates on different methods of pretreatment of lignocellulosic feedstocks: a review

Abstract

Lignocellulosic feedstock materials are the most abundant renewable bioresource material available on earth. It is primarily composed of cellulose, hemicellulose, and lignin, which are strongly associated with each other. Pretreatment processes are mainly involved in effective separation of these complex interlinked fractions and increase the accessibility of each individual component, thereby becoming an essential step in a broad range of applications particularly for biomass valorization. However, a major hurdle is the removal of sturdy and rugged lignin component which is highly resistant to solubilization and is also a major inhibitor for hydrolysis of cellulose and hemicellulose. Moreover, other factors such as lignin content, crystalline, and rigid nature of cellulose, production of post-pretreatment inhibitory products and size of feed stock particle limit the digestibility of lignocellulosic biomass. This has led to extensive research in the development of various pretreatment processes. The major pretreatment methods include physical, chemical, and biological approaches. The selection of pretreatment process depends exclusively on the application. As compared to the conventional single pretreatment process, integrated processes combining two or more pretreatment techniques is beneficial in reducing the number of process operational steps besides minimizing the production of undesirable inhibitors. However, an extensive research is still required for the development of new and more efficient pretreatment processes for lignocellulosic feedstocks yielding promising results.

Keywords

Pretreatment / Lignocellulosic biomass / Cellulose / Lignin / Reducing sugars

References

[] Abdullah R, Ueda K, Saka S. Hydrothermal decomposition of various crystalline celluloses as treated by semi-flow hot-compressed water. J Wood Sci, 2014, 60: 278-286.

[] Agbor VB, Cicek N, Sparling R, Berlin A, Levin DB. Biomass pretreatment: fundamentals toward application. Biotechnol Adv, 2011, 29: 675-685.

[] Aimin T, Hongwei Z, Gang C, Guohui X, Wenzhi L. Influence of ultrasound treatment on accessibility and regioselective oxidation reactivity of cellulose. Ultrason Sonochem, 2005, 12: 467-472.

[] Alizadeh H, Teymouri F, Gilbert TI, Dale BE. Pretreatment of switchgrass by ammonia fibre explosion (AFEX). Appl Biochem Biotechnol, 2005, 121: 1133-1141.

[] Alriols MG, Garcia A, Llano Ponte R, Labidi J. Combined organosolv and ultrafiltration lignocellulosic biorefinery process. Chem Eng J, 2010, 157: 113-120.

[] Alriols MG, Tejado A, Blanco M, Mondragon I, Labidi J. Agricultural palm oil tree residues as raw material for cellulose, lignin and hemicelluloses production by ethylene glycol pulping process. Chem Eng J, 2009, 148: 106-114.

[] Alvira P, Tomas-Pejo E, Ballesteros M, Negro MJ. Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: a review. Biores Technol, 2010, 10: 4851-4861.

[] Bajpai P (2016) In Pretreatment of lignocellulosic biomass for biofuel production. Springer Briefs in Molecular Science, pp 17–70

[] Balan V, Souca LDC, Chundawat SPS, Vismeh R, Jones AD, Dale BEJ. Mushroom-spent straw: a potential substrate for an ethanol based biorefinery. Ind Microbiol Biotechnol, 2008, 35: 293-301.

[] Banerjee S, Sen R, Mudliar S, Pandey RA, Chakrabarti T, Satpute D. Alkaline peroxide assisted wet air oxidation pretreatment approach to enhance enzymatic convertibility of rice husk. Biotechnol Prog, 2011, 27: 691-697.

[] Banerjee S, Sen R, Pandey RA, Chakrabarti T, Satpute D, Giri BS, Mudliar S. Evaluation of wet air oxidation as a pretreatment strategy for bioethanol production from rice husk and process optimization. Biomass Bioenerg, 2009, 33: 1680-1686.

[] Behera S, Arora R, Nandhagopal N, Kumar S. Importance of chemical pretreatment for bioconversion of lignocellulosic biomass. Renew Sustain Energy Rev, 2014, 36: 91-106.

[] Ben GD, Miron J. The effect of combined chemical and enzyme treatment on the saccharification and in vitro digestion rate of wheat straw. Biotechnol Bioeng, 1981, 23: 823-831.

[] Boonmanumsin P, Treeboobpha S, Jeamjumnunja K, Luengnaremitchai A, Chaisuwan T, Wongkasemjit S. Release of monomeric sugars from Miscanthus sinensis by microwave assisted ammonia and phosphoric acid treatments. Bioresour Technol, 2012, 103: 425-431.

[] Brinchi L, Contana F, Fortunati E, Kenny JM. Production of nanocrystalline cellulose from lignocellulosic biomass: technology and applications. Carbohydr Polym, 2013, 94: 154-169.

[] Brodeur G, Yau E, Badal K, Collier J, Ramachandran KB, Ramakrishnan S (2011) Chemical and physicochemical pretreatment of lignocellulosic biomass: A review. Enzyme Res 2011:787532. doi:10.4061/2011/787532

[] Bussemaker MJ, Zhang D. Effect of ultrasound on lignocellulosic biomass as a pretreatment for biorefinery and biofuel applications. Ind Eng Chem Res, 2013, 52: 3563-3580.

[] Cao W, Sun C, Liu R, Yin R, Wu X. Comparison of the effects of five pretreatment methods on enhancing the enzymatic digestibility and ethanol production from sweet sorghum bagasse. Bioresour Technol, 2012, 111: 215-221.

[] Castoldi R, Bracht A, de Morais GR, Baesso ML, Correa RCG, Peralta RA, Moreira RFPM, Polizeli MT, de Souz CGM, Peralta RM. Biological pretreatment of Eucalyptus grandis sawdust with white-rot fungi: study of degradation patterns and saccharification kinetics. Chem Eng J, 2014, 258: 240-246.

[] Chandel AK, Goncalves BC, Strap JL, de Silva SS. Biodelignification of lignocellulose substrates: an intrinsic and sustainable pretreatment strategy for clean energy production. Crit Rev Biotechn, 2015, 35: 281-293.

[] Chang VS, Burr B, Holtzapple MT. Lime pretreatment of switchgrass. Appl Biochem Biotechnol, 1997, 63–65: 3-19.

[] Chaturvedi V, Verma P. An overview of key pretreatment processes employed for bioconversion of lignocellulosic biomass into biofuels and value added products. 3. Biotech, 2013, 3: 415-431.

[] Chen W, Yu H, Liu Y, Chen P, Zhang M, Hai Y. Individualization of cellulose nanofibers from wood using high-intensity ultrasonication combined with chemical pretreatments. Carbohy Polym, 2011, 83: 1804-1811.

[] Chen WH, Tu YJ, Sheen HK. Disruption of sugarcane bagasse lignocellulosic structure by means of dilute sulfuric acid pretreatment with microwave-assisted heating. Appl Energy, 2011, 88: 2726-2734.

[] Cheng YS, Zheng Y, Yu CW, Dooley TM, Jenkins BM, Gheynst JSV. Evaluation of high solids alkaline pretreatment of rice straw. Appl Biochem Biotech, 2010, 162: 1768-1784.

[] Choi S, Song CW, Shin JH, Lee SY. Biorefineries for the production of top building block chemicals and their derivatives. Metab Eng, 2015, 28: 223-239.

[] Cianchetta S, Maggio BD, Burzi PL, Galletti S. Evaluation of selected white-rot fungal isolates for improving the sugar yield from wheat straw. Appl Biochem Biotechnol, 2014, 173: 609-623.

[] Dadi AP, Varanasi S, Schall CA. Enhancement of cellulose saccharification kinetics using an ionic liquid pretreatment step. Biotechnol Bioeng, 2006, 95: 904-910.

[] Dai Y, van Spronsen J, Witkamp G-J, Verpoorte R, Choi YH. Natural deep eutectic solvents as new potential media for green technology. Anal Chim Acta, 2013, 766: 61-68.

[] Dai Y, Witkamp GJ, Verpoorte R, Choi YH (2015) Tailoring properties of natural deep eutectic solvents with water to facilitate their applications. Food Chem 187:14–19

[] Delidovich I, Hausoul PJC, Deng L, Pfutzenreuter R, Rose M, Palkovits R. Alternative monomers based on lignocellulose and their use for polymer production. Chem Rev, 2016, 116: 1540-1599.

[] Dhiman SS, Haw J, Kalyani D, Kalia VC, Kang YC, Lee J. Simultaneous pretreatment and saccharification: green technology for enhanced sugar yields from biomass using a fungal consortium. Bioresour Technol, 2015, 179: 50-57.

[] Digman MF, Shinners KJ, Casler MD. Optimizing on-farm pretreatment of perennial grasses for fuel ethanol production. Bioresour Technol, 2010, 101: 5305-5314.

[] Du W, Yu H, Song L, Zhang J, Weng C, Ma F, Zhang X. The promising effects of by-products from Irpex lacteus on subsequent enzymatic hydrolysis of bio-pretreated corn stalks. Biotechnol Biofuels, 2011, 4: 37.

[] Fan LT, Gharpuray MM, Lee YH. Cellulose hydrolysis biotechnology monographs, 1987, Berlin: Springer, 57.

[] Geng A, Xin F, Ip JY. Ethanol production from horticultural waste treated by a modified organosolv method. Bioresour Technol, 2012, 104: 715-721.

[] Gogate PR, Sutkar VS, Pandit AB. Sonochemical reactors: important design and scale up considerations with a special emphasis on heterogeneous systems. Chem Eng J, 2011, 166: 1066-1082.

[] Grous WR, Converse AO, Grethlein HE. Effect of steam explosion pretreatment on pore size and enzymatic hydrolysis of poplar. Enzyme Microb Technol, 1986, 8: 274-280.

[] Hammel KE, Kapich AN, Jensen KA, Ryan ZC. Reactive oxygen species as agents of wood decay by fungi. Enz Microb Technol, 2002, 30: 445-453.

[] Hendricks AT, Zeeman G. Pretreatments to enhance the digestibility of lignocellulosic biomass. Bioresour Technol, 2009, 100: 10-18.

[] Hideno A, Inoue H, Tsukahara K, Fujimoto S, Minowa T, Inoue S, Endo T, Sawayama S. Wet disk milling pretreatment without sulfuric acid for enzymatic hydrolysis of rice straw. Bioresour Technol, 2009, 100: 2706-2711.

[] Hideno A, Kawashima A, Endo T, Honda K, Morita M. Ethanol-based organosolv treatment with trace hydrochloric acid improves the enzymatic digestibility of Japanese cypress (Chamaecyparis obtusa) by exposing nanofibers on the surface. Bioresour Technol, 2013, 18: 64-70.

[] Hu ZH, Wen ZY. Enhancing enzymatic digestibility of switchgrass by microwave-assisted alkali pretreatment. Biochem Eng J, 2008, 38: 369-378.

[] Huijgen WJJ, Van der Laan RR, Reith JH (2008) Modified organosolv as a fractionation process of lignocellulosic biomass for coproduction of fuels and chemicals. In: Proceedings of the 16th European biomass conference and exhibition, Valencia

[] Ibrahim MM, El-Zawawy WK, Abdel-Fattah YR, Soliman NA, Agblevor FA. Comparison of alkaline pulping with steam explosion for glucose production from rice straw. Carbohydr Polym, 2011, 83: 720-726.

[] Ichwan M, Son TW (2011) Study on organosolv pulping methods of oil palm biomass. In: International seminar on chemistry. pp 364–370

[] Idrees M, Adnan A, Qureshi FA. Optimization of sulfide/sulfite pretreatment of lignocellulosic biomass for lactic acid production. BioMed Research International, 2013, 2013: 1-11.

[] Jacquet N, Vanderghem C, Danthine S, Quiévy N, Blecker C, Devaux J, Paquot M. Influence of steam explosion on physicochemical properties and hydrolysis rate of pure cellulose fibers. Bioresour Technol, 2012, 121: 221-227.

[] Jagmann N, Philipp B. Design of synthetic microbial communities for biotechnological production processes. J Biotechnol, 2014, 184: 209-218.

[] Kang S, Li X, Fan J, Chang J. Hydrothermal conversion of lignin: a review. Renew Sust Ener Rev, 2013, 27: 546-558.

[] Karunanithy C, Muthukumarappan K. Influence of extruder temperature and screw speed on pretreatment of corn stover while varying enzymes and their ratios. Appl Biochem Biotechnol, 2010, 162: 264-279.

[] Karunanithy C, Muthukumarappan K, Gibbons WR. Effect of extruder screw speed, temperature, and enzyme levels on sugar recovery from different biomasses. ISRN Biotechnol, 2013, 942810: 1-13.

[] Karunanithy C, Muthukumarappan K, Julson JL (2008) Influence of high shear bioreactor parameters on carbohydrate release from different biomasses. American Society of Agricultural and Biological Engineers, Annual International Meeting 2008. ASABE 084114. ASABE, St. Joseph

[] Karunanithy V, Muthukumarappan K. Optimizing extrusion pretreatment and big bluestem parameters for enzymatic hydrolysis to produce biofuel using response surface methodology. Int J Agric Biol Eng, 2011, 4: 61-74.

[] Keshwani DR, Cheng JJ. Microwave-based alkali pretreatment of switchgrass and coastal bermudagrass for bioethanol production. Biotechnol Prog, 2010, 3: 644-652.

[] Kilzer FJ, Broido A. Speculations on the nature of cellulose pyrolysis. Pyrodynamics, 1965, 2: 151-163.

[] Kim HJ, Chang JH, Jeong BY, Lee JH. Comparison of milling modes as a pretreatment method for cellulosic biofuel production. J Clean Energy Technol, 2013, 1: 45-48.

[] Kim HK, Hong J. Supercritical CO₂ pretreatment of lignocellulose enhances enzymatic cellulose hydrolysis. Bioresour Technol, 2001, 77: 139-144.

[] Kim JS, Kim H, Lee JS, Lee JP, Park SC. Pretreatment characteristics of waste oak wood by ammonia percolation. Appl Biochem Biotechnol, 2008, 148: 15-22.

[] Kim JW, Kim KS, Lee JS, Park SM, Cho HY, Park JC, Kim JS. Two-stage pretreatment of rice straw using aqueous ammonia and dilute acid. Bioresour Technol, 2011, 102: 8992-8999.

[] Kim TH, Lee YY. Pretreatment and fractionation of corn stover by soaking in aqueous ammonia. Appl Biochem Biotechnol, 2005, 121: 1119-1131.

[] Kim TH, Lee YY. Pretreatment of corn stover by ammonia recycle percolation process. Bioresour Technol, 2005, 96: 2007-2013.

[] Kim Y, Yu A, Han M, Choi GW, Chung B. Enhanced enzymatic saccharification of barley straw pretreated by ethanosolv technology. Appl Biochem Biotechnol, 2011, 163: 143-152.

[] Kleinert M, Barth T. Phenols from lignin. Chem Eng Technol, 2008, 31: 736-745.

[] Koo BW, Min BC, Gwak KS. Structural changes in lignin during organosolv pretreatment of Liriodendron tulipifera and the effect on enzymatic hydrolysis. Biomass Bioenerg, 2012, 42: 24-32.

[] Kootstra AM, Beeftink HH, Scott EL, Sanders JPM. Comparison of dilute mineral and organic acid pretreatment for enzymatic hydrolysis of wheat straw. Biochem Eng J, 2009, 46: 126-131.

[] Kumar AK, Parikh BS, Pravakar M. Natural deep eutectic solvent mediated pretreatment of rice straw: bioanalytical characterization of lignin extract and enzymatic hydrolysis of pretreated biomass residue. Environ Sci Pollut Res Int, 2016, 23: 9265-9275.

[] Kumar P, Barrett DM, Delwiche MJ, Stroeve P. Methods for pretreatment of lignocellulosic biomass for efficient hydrolysis and biofuel production. Ind Eng Chem Res, 2009, 48: 3713-3729.

[] Kumar P, Barrett DM, Delwiche MJ, Stroeve P. Pulsed electric field pretreatment of switchgrass and woodchips species for biofuels production. Ind Eng Chem Res, 2011, 50: 10996-11001.

[] 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.

[] Kuo CH, Lee CK. Enhanced enzymatic hydrolysis of sugarcane bagasse by N methylmorpholine-N-oxide pretreatment. Bioresour Technol, 2009, 100: 866-871.

[] Lamsal B, Yoo J, Brijwani K, Alavi S. Extrusion as a thermo-mechanical pre-treatment for lignocellulosic ethanol. Biomass Bioenerg, 2010, 34: 1703-1710.

[] Laser M, Larson E, Dale B, Wang M, Greene N, Lynd LR. Comparative analysis of efficiency, environmental impact, and process economics for mature biomass refining scenarios. Biofpr, 2009, 3: 247-270.

[] Lee J, Houtman CJ, Kim HY, Choi IG, Jeffries TW. Scale-up study of oxalic acid pretreatment of agricultural lignocellulosic biomass for the production of bioethanol. Bioresour Technol, 2011, 102: 7451-7456.

[] Lee J, Jeffries TW. Efficiencies of acid catalysts in the hydrolysis of lignocellulosic biomass over a range of combined severity factors. Bioresour Technol, 2011, 102: 5884-5890.

[] Lee JW, Rodrigues RCLB, Jeffries TW. Simultaneous saccharification and ethanol fermentation of oxalic acid pretreated corncob assessed with response surface methodology. Bioresour Technol, 2009, 100: 6307-6311.

[] Li L, Yu ST, Liu FS, Xie CS, Xu CZ. Efficient enzymatic in situ saccharification of cellulose in aqueous-ionic liquid media by microwave treatment. BioResources, 2011, 6: 4494-4504.

[] Lin Z, Huang H, Zhang H, Zhang L, Yan L, Chen J. Ball milling pretreatment of corn stover for enhancing the efficiency of enzymatic hydrolysis. Appl Biochem Biotechnol, 2010, 162: 1872-1880.

[] Liu LY, Chen HZ. Enzymatic hydrolysis of cellulose materials treated with ionic liquid [BMIM] Cl. Chin Sci Bull, 2006, 51: 2432-2436.

[] Lu X, Xi B, Zhang Y, Angelidaki I. Microwave pretreatment of rape straw for bioethanol production: focus on energy efficiency. Bioresour Technol, 2011, 102: 7937-7940.

[] Lu Y, Mosier NS. Biomimetic catalysis for hemicelluloses hydrolysis in corn stover. Biotechnol Progr, 2007, 23: 116-123.

[] Lucas M, Hanson SK, Wagner GL, Kimball DB, Rector KD. Evidence for room temperature delignification of wood using hydrogen peroxide and manganese acetate as a catalyst. Bioresour Technol, 2012, 119: 174-180.

[] Luengo E, Martínez JM, Coustets M, Álvarez I, Teissié J, Rols MP, Raso J. A comparative study on the effects of millisecond and microsecond-pulsed electric field treatments on the permeabilization and extraction of pigments from Chlorella vulgaris. J Membrane Biol, 2015, 248: 883-891.

[] Lynd LR, Elander RT, Wyman CE. Likely features and costs of mature biomass ethanol technology. App Biochem Biotechnol, 1996, 57: 741-761.

[] Ma F, Yang N, Xu C, Yu H, Wu J, Zhang X. Combination of biological pretreatment with mild acid pretreatment for enzymatic hydrolysis and ethanol production from water hyacinth. Bioresour Technol, 2010, 101: 9600-9604.

[] Ma R, Xu Y, Zhang X. Catalytic oxidation of biorefinery lignin to value-added chemicals to support sustainable biofuel production. Chem Sus Chem, 2015, 8: 24-51.

[] Marzialetti T, Olarte MBV, Sievers C, Hoskins TJC, Agrawal PK, Jones CW. Dilute acid hydrolysis of loblolly pine: a comprehensive approach. Ind Eng Chem Res, 2008, 47: 7131-7140.

[] McIntosh S, Vancov T. Enhanced enzyme saccharification of Sorghum bicolor straw using dilute alkali pretreatment. Bioresour Technol, 2010, 101: 6718-6727.

[] Mesa L, González E, Cara C, González M, Castro E, Mussatto SI. The effect of organosolv pretreatment variables on enzymatic hydrolysis of sugarcane bagasse. Chem Eng J, 2011, 168: 1157-1162.

[] Montalbo LM, Johnson L, Khanal SK, Leeuwene JV, Grewell D. Sonication of sugary-2 corn: a potential pretreatment to enhance sugar release. Bioresour Technol, 2010, 101: 351-358.

[] Mosier N, Wyman CE, Dale BE, Elander R, Lee YY, Holtzapple MT, Ladisch M. Features of promising technologies for pretreatment of lignocellulosic biomass. Bioresour Technol, 2005, 96: 673-686.

[] Mosier NS, Ladisch CM, Ladisch MR. Characterization of acid catalytic domains for cellulose hydrolysis and glucose degradation. Biotechnol Bioeng, 2002, 79(6): 610-618.

[] Moultrop JS, Swatloski RP, Moyna G, Rogers RD (2005) High resolution 13-C NMR studies of cellulose and cellulose oligomers in ionic liquid solutions. Chem Commun 2005:1557–1559

[] Nakamura Y, Daidai M, Kobayashi F. Ozonolysis mechanism of lignin model compounds and microbial treatment of organic acids produced. Water Sci Technol, 2004, 50: 167-172.

[] Neely WC. Factors affecting the pretreatment of biomass with gaseous ozone. Biotechnol Bioeng, 1984, 26: 59-65.

[] Ni M, Leung DYC, Leung MKH, Sumathy K. An overview of hydrogen production from biomass. Fuel Process Technol, 2006, 87: 461-472.

[] Nomanbhay SM, Hussain R, Palanisamy K. Microwave assisted enzymatic saccharification of oil palm empty fruit bunch fiber for enhanced fermentable sugar yield. J Sustain Bioenergy Syst, 2013, 3: 7-17.

[] Ogura M, Phaiboonsilpa N, Yamauchi K, Saka S. Two-step decomposition behavior of rice straw as treated by semi-flow hot-compressed water (in Japanese). J Jpn Inst Energy, 2013, 92: 456.

[] Paiva A, Craveir R, Aroso I, Martins M, Reis RL, Duarte ARC. Natural deep eutectic solvents—solvents for the 21st century. ACS Sustain Chem Eng, 2014, 2: 1063-1071.

[] Panagiotopoulos IA, Chandra RP, Saddler JN. A two-stage pretreatment approach to maximise sugar yield and enhance reactive lignin recovery from poplar wood chips. Bioresour Technol, 2012, 130: 570-577.

[] Park JY, Shiroma R, Al-Haq MI, Zhang Y, Ike M, Arai-Sanoh Y, Ida A, Kondo M, Tokuyasu K. A novel lime pretreatment for subsequent bioethanol production from rice straw—calcium capturing by carbonation (CaCCO) process. Bioresour Technol, 2010, 101: 6805-6811.

[] Park N, Kim HY, Koo BW, Yeo H, Choi IG. Organosolv pretreatment with various catalysts for enhancing enzymatic hydrolysis of pitch pine (Pinus rigida). Bioresour Technol, 2010, 101: 7046-7053.

[] Phaiboonsilpa N (2010) Chemical conversion of lignocellulosics as treated by two step semi-flow hot-compressed water. In: Graduate School of Energy Science, Doctoral dissertation, Kyoto University, Kyoto

[] Potumarthi R, Baadhe RR, Nayak P, Jetty A. Simultaneous pretreatment and saccharification of rice husk by Phanerochete chrysosporium for improved production of reducing sugars. Bioresour Technol, 2013, 128: 113-117.

[] Prado R, Erdocia X, Serrano L, Labidi J. Lignin purification with green solvents. Cellul Chem Technol, 2012, 46: 221-225.

[] Putro JN, Soetaredjo FE, Lin SY, Ju YH, Ismadi S. Pretreatment and conversion of lignocellulose biomass into valuable chemicals. RSC Adv, 2016, 6: 46834-46852.

[] Quesada J, Rubio M, Gomez D. Ozonation of lignin rich solid fractions from corn stalks. J Wood Chem Technol, 1999, 19: 115-137.

[] Rabemanolontsoa H, Saka S. Various pretreatments of lignocellulosics. Bioresour Technol, 2016, 199: 83-91.

[] Rehman MSU, Kim I, Chisti Y, Han JI. Use of ultrasound in the production of bioethanol from lignocellulosic biomass. EEST Part A Energy Sci Res, 2013, 30: 1391-1410.

[] Roberts VM, Stein V, Reiner T, Lemonidou A, Li X, Lercher JA. Towards quantitative catalytic lignin depolymerization. Chem Eur J, 2011, 17: 5939-5948.

[] Romero A, Alonso A, Sastre A, Marquez AN. Conversion of biomass into sorbitol: cellulose hydrolysis on MCM-48 and d-Glucose hydrogenation on Ru/MCM-48. Micropor Mesopor Mat, 2016, 224: 1-8.

[] Saha BC, Cotta MA. Enzymatic saccharification and fermentation of alkaline peroxide pretreated rice hulls to ethanol. Enzyme Microb Technol, 2007, 41: 528-532.

[] Saha BC, Iten BL, Cotta M, Wu YV. Dilute acid pretreatment, enzymatic saccharification, and fermentation of rice hulls to ethanol. Biotechnol Prog, 2005, 21: 3816-3822.

[] Salerno MB, Lee HS, Parameswaran P, Rittmann BE (2009) Using a pulsed electric field as a pretreatment for improved biosolids digestion and methanogenesis. Water Environment Federation WEFTEC. 2005–2018

[] Sánchez C. Lignocellulosic residues: biodegradation and bioconversion by fungi. Biotechnol Adv, 2009, 27: 185-194.

[] Sant’ Ana daSilva A, Inoue H, Endo T, Yano S, Bon EPS. Milling pretreatment of sugarcane bagasse and straw for enzymatic hydrolysis and ethanol fermentation. Biores Technol, 2010, 101: 7402-7409.

[] Sarkar N, Ghosh SK, Bannerjee S, Aikat K. Bioethanol production from agricultural wastes: an overview. Renew Energy, 2012, 37: 19-27.

[] Sassner P, Martensson CG, Galbe M, Zacchi G. Steam pretreatment of H₂SO₄ impregnated salix for the production of bioethanol. Biores Technol, 2008, 99: 137-145.

[] Sawada T, Nakmura Y, Kobayashi F, Kuwahara M, Watanabe T. Effects of fungal pretreatment and steam explosion pretreatment on enzymatic saccharification of plant biomass. Biotechnol Bioeng, 1995, 48: 719-724.

[] Shafizadeh F, Bradbury AGW. Thermal degradation of cellulose in air and nitrogen at low temperatures. J Appl Poly Sci, 1979, 23: 1431-1442.

[] Shi J, Chinn MS, Sharma-Shivappa RR. Microbial pretreatment of cotton stalks by solid state cultivation of Phanerochaete chrysosporium. Bioresour Technol, 2008, 99: 6556-6564.

[] Shuai L, Yang Q, Zhu JY, Lu FC, Weimer PJ, Ralph J, Pan XJ. Comparative study of SPORL and dilute-acid pretreatments of spruce for cellulosic ethanol production. Biores Technol, 2010, 101: 3106-3114.

[] Sills DL, Gossett JM. Assessment of commercial hemicellulases for saccharification of alkaline pretreated perennial biomass. Biores Technol, 2011, 102: 1389-1398.

[] Sindhu R, Binod P, Pandey A. Biological pretreatment of lignocellulosic biomass—an overview. Bioresour Technol, 2016, 199: 76-82.

[] Sivagurunathan P, Kumar G, Bakonyi P, Kim SH, Kobayashi T, Xu KQ, Lakner G, Toth G, Nemestothy N, Bako KB. A critical review on issues and overcoming strategies for the enhancement of dark fermentative hydrogen production in continuous systems. Int J Hydrogen Energy, 2016, 41: 3820-3836.

[] Smith EL, Abbott AP, Ryder KS. Deep eutectic solvents (DESs) and Their applications. Chem Rev, 2014, 114: 11060-11082.

[] Song L, Yu H, Ma F, Zhang X. Biological pretreatment under non-sterile conditions for enzymatic hydrolysis of corn stover. BioResources, 2013, 8: 3802-3816.

[] Suhara H, Kodama S, Kamei I, Maekawa N, Meguro S. Screening of selective lignin-degrading basidiomycetes and biological pretreatment for enzymatic hydrolysis of bamboo culms. Int Biodeter Biodegr, 2012, 75: 176-180.

[] Sun R, Lawther JM, Banks WB. Influence of alkaline pre-treatments on the cell wall components of wheat straw. Industrial Crop Prod, 1995, 2: 127-145.

[] Sun RC, Tomkinson J. Comparative study of lignins isolated by alkali and ultrasound-assisted alkali extractions from wheat straw. Ultrason Sonochem, 2002, 9: 85-93.

[] Sun Y, Cheng J. Hydrolysis of lignocellulosic materials for ethanol production: a review. Bioresour Technol, 2002, 83: 1-11.

[] Sun YE, Cheng JJ. Dilute acid pretreatment of rye straw and Bermuda grass for ethanol production. Bioresour Technol, 2005, 96: 1599-1606.

[] Szijártó N, Kádár Z, Varga E, Thomsen AB, Costa-Ferreira M, Réczey K. Pretreatment of reed by wet oxidation and subsequent utilization of the pretreated fibers for ethanol production. Appl Biochem Biotechnol, 2009, 155: 386-396.

[] Taha M, Shahsavari E, Al-Hothaly K, Mouradov A, Smith AT, Ball AS, Adetutu EM. Enhanced biological straw saccharification through co-culturing of lignocellulose degrading microorganisms. Appl Biochem Biotechnol, 2015, 175: 3709-3728.

[] Taherzadeh MJ, Karimi K. Pretreatment of lignocellulosic wastes to improve ethanol and biogas production: a review. Int J Mol Sci, 2008, 9: 1621-1651.

[] Tang J, Chen K, Huang F, Xu J, Li J. Characterization of the pretreatment liquor of biomass from the perennial grass, Eulaliopsis binata, for the production of dissolving pulp. Bioresour Technol, 2013, 129: 548-552.

[] Uppugundla N, Da Costa Sousa L, Chundawat SPS, Yu X, Simmons B, Singh S, Gao X, Kumar R, Wyman CE, Dale BE, Balan V. A comparative study of ethanol production using dilute acid, ionic liquid and AFEXTM pretreated corn stover. Biotechnol Biofuel, 2014, 7: 72-85.

[] Varga E, Schmidt AS, Réczey K, Thomsen AB. Pretreatment of corn stover using wet oxidation to enhance enzymatic digestibility. Appl Biochem Biotechnol, 2003, 104: 37-50.

[] Vats S, Maurya DP, Shaimoon M, Negi S. Development of a microbial consortium for the production of blend enzymes for the hydrolysis of agricultural waste into sugars. J Sci Ind Res, 2013, 72: 585-590.

[] Vidal PF, Molinier J. Ozonolysis of lignin—improvement of in vitro digestibility of poplar sawdust. Biomass, 1988, 16: 1-17.

[] Villaverde JJ, Ligero P, De Vega A. Miscanthus x giganteus as a source of biobased products through organosolv fractionation: a mini review. Open Agric J, 2010, 4: 102-110.

[] Wan C, Li Y. Effectiveness of microbial pretreatment by Ceriporiopsis subvermispora on different biomass feed stocks. Bioresour Technol, 2011, 102: 7507-7512.

[] Wang L, Mu G, Tan C, Sun L, Zhou W, Yu P, Yin J, Fu H. Porous graphitic carbon nanosheets derived from cornstalk biomass for advanced supercapacitors. Chem Sus Chem, 2013, 6: 880-889.

[] Wang W, Yuan T, Wang K, Cui B, Dai Y. Combination of biological pretreatment with liquid hot water pretreatment to enhance enzymatic hydrolysis of Populus tomentosa. Bioresour Technol, 2012, 107: 282-286.

[] Wright JD. Ethanol from biomass by enzymatic hydrolysis. Chem Eng Prog, 1988, 84: 62-74.

[] Wyman CE. Biomass ethanol: technical progress, opportunities, and commercial challenges. Ann Rev Energy Environ, 1999, 24: 189-226.

[] Xu H, Li B, Mu X. Review of alkali-based pretreatment to enhance enzymatic saccharification for lignocellulosic biomass conversion. Ind Eng Chem Res, 2016, 55: 8691-8705.

[] Xu J, Chen H, Kadar Z, Thomsen AB, Schmidt JE, Peng H. Optimization of microwave pretreatment on wheat straw for ethanol production. Biomass Bioenerg, 2011, 35: 385-386.

[] Xu J, Thomsen MH, Thomsen AB. Pretreatment on corn stover with low concentration of formic acid. J Microbiol Biotechnol, 2009, 19: 845-850.

[] Yachmenev V, Condon B, Klasson T, Lambert A. Acceleration of the enzymatic hydrolysis of corn stover and sugar cane bagasse celluloses by low intensity uniform ultrasound. J Biobased Mater Bioenergy, 2009, 3: 25-31.

[] Yang B, Wyman CE. Effect of xylan and lignin removal by batch and flow through pretreatment on enzymatic digestibility of corn stover cellulose. Biotechnol Bioeng, 2004, 86: 88-95.

[] Yang J, Christiansen K, Luchner S. Renewable, low-cost carbon fiber for light weight vehicles, 2013, U.S. Department of Energy: Detroit.

[] Yoo JY (2011) Technical and economical assessment of thermo-mechanical extrusion pretreatment for cellulosic ethanol production. Ph.D. Thesis, Kansas State University, Manhattan

[] Yoshikawa T, Yagi T, Shinohara S, Fukunaga T, Nakasaka Y, Tago T, Masuda T. Production of phenols from lignin via depolymerization and catalytic cracking. Fuel Process Technol, 2013, 108: 69-75.

[] Yu J, Zhang J, He J, Liu Z, Yu Z. Combinations of mild physical or chemical pretreatment with biological pretreatment for enzymatic hydrolysis of rice hull. Bioresour Technol, 2009, 100: 903-908.

[] Yu X, Gouyo T, Grimi N, Bals O, Vorobiev E. Pulsed electric field pretreatment of rapeseed green biomass (stems) to enhance pressing and extractives recovery. Bioresour Technol, 2016, 199: 194-201.

[] Zakaria MR, Fujimoto S, Hirata S, Hassan MA. Ball milling pretreatment of oil palm biomass for enhancing enzymatic hydrolysis. Appl Biochem Biotechnol, 2014, 173: 1778-1789.

[] Zavrel M, Bross D, Funke M, Buchs J, Spiess AC. High-throughput screening for ionic liquids dissolving (ligno-)cellulose. Bioresour Technol, 2009, 100: 2580-2587.

[] Zhang DS, Yang Q, Zhu JY, Pan XJ. Sulfite (SPORL) pretreatment of switchgrass for enzymatic saccharification. Bioresour Technol, 2013, 129: 127-134.

[] Zhang SH, Xu YX, Hanna MA. Pretreatment of corn stover with twin-screw extrusion followed by enzymatic saccharification. Appl Biochem Biotechnol, 2012, 166: 458-469.

[] Zhang Q, De Vigier KO, Royer S, Jérôme F. Deep eutectic solvents: syntheses, properties and applications. Chem Soc Rev, 2012, 41: 7108-7146.

[] Zhao X, Liu D. Fractionating pretreatment of sugarcane bagasse by aqueous formic acid with direct recycle of spent liquor to increase cellulose digestibility-the Formiline process. Bioresour Technol, 2012, 117: 25-32.

[] Zhao Y, Wang Y, Zhu JY, Ragauskas A, Deng Y. Enhanced enzymatic hydrolysis of spruce by alkaline pretreatment at low temperature. Biotechnol Bioeng, 2008, 99: 1320-1328.

[] Zheng J, Rehmann L. Extrusion pretreatment of lignocellulosic biomass: a review. Int J Mol Sci, 2014, 15: 18967-18984.

[] Zheng YZ, Lin HM, Tsao GT. Supercritical carbon-dioxide explosion as a pretreatment for cellulose hydrolysis. Biotechnol Lett, 1995, 17: 845-850.

[] Zhu J, Rezende CA, Simister R, McQueen-Mason SJ, Macquarrie DJ, Polikarpov I, Gomez LD. Efficient sugar production from sugarcane bagasse by microwave assisted acid and alkali pretreatment. Biomass Bioenerg, 2016, 93: 269-278.

[] Zhu J, Wan C, Li Y. Enhanced solid-state anaerobic digestion of corn stover by alkaline pretreatment. Bioresour Technol, 2010, 101: 7523-7528.

[] Zhu JY, Pan XJ. Woody biomass pretreatment for cellulosic ethanol production technology and energy consumption evaluation. Bioresour Technol, 2010, 101: 4992-5002.

[] Zhu JY, Pan XJ, Wang GS, Gleisner R. Sulfite pretreatment (SPORL) for robust enzymatic saccharification of spruce and red pine. Bioresour Technol, 2009, 100: 2411-2418.

[] Zhu Z, Macquarrie DJ, Simister R, Gomez LD, McQueen-Mason SJ. Microwave assisted chemical pretreatment of Miscanthus under different temperature regimes. Sustain Chem Process, 2015, 3: 15-27.

[] Zhu Z, Simister R, Bird S, McQueen-Mason SJ, Gomez LD, Macquarrie DJ. Microwave assisted acid and alkali pretreatment of Miscanthus biomass for biorefineries. AIMS Bioeng, 2015, 2: 449-468.

[] Zhua JY, Wang GS, Pan XJ, Gleisner R. Specific surface to evaluate the efficiencies of milling and pretreatment of wood for enzymatic saccharification. Chem Eng Sci, 2009, 64: 474-485.

[] Zwart RWR, Boerrigter H, Van der Drift A. The impact of biomass pretreatment on the feasibility of overseas biomass conversion to fischer-tropsch products. Energy Fuels, 2006, 20: 2192-2197.

Funding

Indian Council of Agricultural Research(VVN/RES/DRET-LBT/2014/3); Department of Biotechnology , Ministry of Science and Technology(BT/PR12368/PDB/26/431/2014)