Effect of [EMIM]Ac Recycling on Salix gracilistyla Miq. Pretreatment for Enzymatic Saccharification

  • HAN, Song-Yi (Institute of Forest Science, Kangwon National University) ;
  • PARK, Chan-Woo (Institute of Forest Science, Kangwon National University) ;
  • KWON, Gu-Joong (Institute of Forest Science, Kangwon National University) ;
  • KIM, Jong-Ho (Institute of Forest Science, Kangwon National University) ;
  • KIM, Nam-Hun (Institute of Forest Science, Kangwon National University) ;
  • LEE, Seung-Hwan (Institute of Forest Science, Kangwon National University)
  • Received : 2020.02.17
  • Accepted : 2020.05.01
  • Published : 2020.05.25


Recycling of ionic liquid (1-ethyl-3-methylimidazolium acetate, [EMIM]Ac) after the pretreatment of Salix gracilistyla Miq. was conducted and the effect of the recycling number on the enzymatic saccharification yield was investigated. Enzymatic saccharification was performed using an enzyme cocktail (Acremonium cellulase and Optimash BG) at 50 ℃ for 72 h. All recycled [EMIM]Ac samples showed a lower amount of water soluble fraction than pure [EMIM]Ac. On increasing the recycling number from 1 to 4, the amount of water soluble fraction decreased from 18% to 15%. The X-ray diffraction pattern of the products pretreated with recycled [EMIM]Ac showed cellulose I crystalline polymorph. The crystallinity of the product pretreated with recycled [EMIM]Ac was 47-49%, which was lower than 33% of that with pure [EMIM]Ac. The yields of glucose and xylose decreased in the pretreatment with recycled [EMIM]Ac compared to that with pure [EMIM]Ac.


  1. Yanti, H., Syafii, W., Wistara, N.J., Febrianto, F., Kim, N.H. 2019. Effect of Biological and Liquid Hot Water Pretreatments on Ethanol Yield from Mengkuang (Pandanus artocarpus Griff). Journal of the Korean Wood Science and Technology 47(2): 145-162.
  2. Zhang, J., Wang, Y., Zhang, L., Zhang, R., Liu, G., Cheng, G. 2014. Understanding changes in cellulose crystalline structure of lignocellulosic biomass during ionic liquid pretreatment by XRD. Bioresource Technology 151: 402-405.
  3. Cheenkachorn, K., Douzou, T., Roddecha, S., Tantayotai, P., Tantayotai, P., Sriariyanun, M. 2016. Enzymatic saccharification of rice straw under influence of recycled ionic liquid pretreatments. Energy Procedia 100: 160-165.
  4. Cui, T., Li, J., Yan, Z., Yu, M., Li, S. 2014. The correlation between the enzymatic saccharification and the multidimensional structure of cellulose changed by different pretreatments. Biotechnology for Biofuels 7: 134.
  5. Ding, J.C., Xu, G.C., Han, R.Z., Ni, Y. 2016. Biobutanol production from corn stover hydrolysate pretreated with recycled ionic liquid by Clostridium saccharobutylicum DSM 13864. Bioresource Technology 199: 228-234.
  6. Dutta, T., Shi, J., Sun, J., Zhang, X., Cheng, G., Simmons, B.A., Singh, S. 2016. Ionic liquid pretreatment of lignocellulosic biomass for biofuels and chemicals. In: Ionic liquids in the biorefinery concept: challenges and perspectives. RSC Green Chemistry Ser. 36, Ed. by Bogel-Lukasik, R., Royal Society of Chemistry, Cambridge, UK.
  7. Elgharbawy, A.A., Alam, M.Z., Moniruzzaman, M., Goto, M. 2016. Ionic liquid pretreatment as emerging approaches for enhanced enzymatic hydrolysis of lignocellulosic biomass. Biochemical Engineering Journal 109: 252-267.
  8. George, A., Brandt, A., Tran, K., Zahari, S.M.S.N.S., Klein-Marcuschamer, D., Sun, N., Sathitsuksanoh, N., Shi, J., Stavila, V., Parthasarathi, R., Singh, S., Holmes, B.M., Welton, T., Simmons, B.A., Hallett, J.P. 2015. Design of low-cost ionic liquids for lignocellulosic biomass pretreatment. Green Chemistry 17(3): 1728-1734.
  9. Hall, M., Bansal, P., Lee, J.H., Realff, M.J., Bommarius A.S. 2010. Cellulose crystallinity-a key predictor of the enzymatic hydrolysis rate. The FEBS Journal 277(6): 1571-1582.
  10. Hamidah, U., Arakawa, T., H’ng, Y.Y., Nakagawaizumi, A., Kishino, M. 2018. Recycled ionic liquid 1-ethyl-3-methylimidazolium acetate pretreatment for enhancing enzymatic saccharification of softwood without cellulose regeneration. Journal of Wood Science 64(2): 149-156.
  11. Han, S.Y., Park, C.W., Kim, N.H., Lee, S.H. 2017a. Co-solvent system of [EMIM]Ac and DMF to improve the enzymatic saccharification of pussy willow (Salix gracilistyla Miq.). Holzforschung 71(1): 43-50.
  12. Han, S.Y., Park, C.W., Lee, S.H. 2017b. Preparation of lignocellulose nanofiber by mechanical defibrillation after pretreatment using cosolvent of ionic liquid and DMF. Journal of the Korean Wood Science and Technology 45(3):268-277.
  13. Han, S.Y., Park, C.W., Febrianto, F., Kim, N.H., Lee, S.H. 2020a. Pretreatment with [EMIM]Ac/DMAc Co-solvent to Improve Enzymatic Saccharification of Pussy Willow (Salix gracilistyla Miq.). Bio-Resources 15(1): 187-198.
  14. Han, S.Y., Park, C.W., Endo, T., Febrianto, F., Kim, N.H., Lee, S.H. 2020b. Extrusion process to enhance the pretreatment effect of ionic liquid for improving enzymatic hydrolysis of lignocellulosic biomass. Wood Science and Technology.
  15. Han, S.Y., Park, C.W., Park, J.B., Ha, S.J., Kim, N.H., Lee, S.H. 2020c. Ethanol fermentation of the enzymatic hydrolysates from the products pretreated using [EMIM]Ac and its co-solvents with DMF. Journal of Forest and Environmental Science 36(1): 62-66.
  16. Hou, X.D., Smith, T.J., Li, N., Zong, M.H. 2012. Novel renewable ionic liquids as highly effective solvents for pretreatment of rice straw biomass by selective removal of lignin. Biotechnology and Bioengineering 109(10): 2484-2493.
  17. Jung, J.Y., Ha, S.Y., Park, J.H., Yang, J.-K. 2017. Optimization of alkali pretreatment from steam exploded barley husk to enhance glucose fraction using response surface methodology. Journal of the Korean Wood Science and Technology 45(2): 182-194.
  18. Kim, J.-Y., Kim, T.-S., Hwang, H., Oh, S., Choi, J.W. 2012. Chemical⋅Structural characterization of lignin extracted from Pitch Pine with Ionic Liquid (1-ethyl-3-methylimidazolium acetate). Journal of the Korean Wood Science and Technology 40(3): 194-203
  19. Kucharska, K., Rybarczyk, P., Holowacz, I., Glinka, M., Kaminski, M. 2018. Pretreatment of lignocellulosic materials as substrates for fermentation processes. Molecules 23(11): 2937.
  20. Kumagai, A., Lee, S.H., Endo, T. 2016. Evaluation of the effect of hot-compressed water treatment on enzymatic hydrolysis of lignocellulosic nanofibrils with different lignin content using a quartz crystal microbalance. Biotechnology and Bioengineering 113(7): 1441-1447.
  21. Lee, S.H., Chang, F., Inoue, S., Endo, T. 2010. Increase in enzyme accessibility by generation of nanospace in cell wall supramolecular structure. Bioresource Technology 101(19): 7218-7223.
  22. Lee, H.S., An, C.H., Kang, J.W., Lee, W.Y., Yi, J.-S. 2018. Investigation of Growth Characteristics of Salix gracilistyla Clones. Journal of Korean Society of Forest Science 107(1): 16-24.
  23. Ling, Z., Chen, S., Zhang, X., Takabe, K., Xu, F. 2017. Unraveling variations of crystalline cellulose induced by ionic liquid and their effects on enzymatic hydrolysis. Scientific Reports 7: 10230.
  24. Park, S.Y., Hwang, H., Jang, S., Choi, I.G., Choi, J. 2015. study on pretreatment of giant miscanthus using ionic liquid and structural change of lignin. Journal of the Korean Wood Science and Technology 43(3): 344-354.
  25. Sangian, H., Kristian, J., Rahma, S., Dewi, H.K., Puspasari, D.A., Agnesty, S.Y., Gunawan, S., Widjaja, A. 2015. Preparation of reducing sugar hydrolyzed from high-lignin coconut coir dust pretreated by the recycled ionic liquid [mmim][dmp] and combination with alkaline. Bulletin of Chemical Reaction Engineering & Catalysis 10(1): 8-22.
  26. Segal, L., Creely, J.J., Martin Jr, A.E., Conrad, C.M. 1959. An empirical method for estimating the degree of crystallinity of native cellulose using the X-ray diffractometer. Textile Research Journals 29(10): 786-794.
  27. Shi, J., Balamurugan, K., Parthasarathi, R., Sathitsuksanoh, N., Zhang, S., Stavila, V., Zhang, S., Stavila, V., Subramanian, V., Simmons, B.A., Singh, S. 2014. Understanding the role of water during ionic liquid pretreatment of lignocellulose: Co-solvent or anti-solvent. Green Chemistry 16(8): 3830-3840.
  28. Sluiter, A., Crocker, D., Hames, B., Ruiz, R., Scarlata, C., Sluiter, J., Templeton, D. 2008. Determination of structural carbohydrates and lignin in biomass," NREL/TP-510-42618.
  29. Wu, L., Lee, S.H., Endo, T. 2013. Effect of dimethyl sulfoxide on ionic liquid 1-ethyl-3-methylimidazolium acetate pretreatment of eucalyptus wood for enzymatic hydrolysis. Bioresource Technology 140: 90-96.
  30. Xu, J., Liu, B., Hou, H., Hu, J. 2017. Pretreatment of eucalyptus with recycled ionic liquids for low-cost biorefinery. Bioresource Technology 234: 406-414.
  31. Yang, B., Wyman, C.E. 2008. Pretreatment: the key to unlocking low-cost cellulosic ethanol. Biofuels, Bioproducts and Biorefining 2(1): 26-40.