Sains Malaysiana 45(6)(2016): 955–962

Effects of Alkaline Combined with Ultrasonic Pretreatment and Enzymatic Hydrolysis of Agricultural Wastes for High Reducing Sugar Production

(Kesan Gabungan Alkali dengan Ultrasonik Prarawatan dan Hidrolisis Enzim Sisa Pertanian untuk Penurunan Pengeluaran Gula yang Tinggi)

WAESARAT SOONTORNCHAIBOON¹, SANG MOO KIM² & RATCHAPOL PAWONGRAT¹*

¹Department of Liberal Arts and Science, Kasetsart University, Nakhon Pathom 73140, Thailand

²Department of Marine Food Science and Technology, Gangneung-Wonju National University

Gangneung 25457, Republic of Korea

Received: 10 February 2015/Accepted: 11 January 2016

ABSTRACT

The effects of six pretreatments of five agricultural wastes (corn cob, pineapple waste, bagasse, rice straw and water hyacinth) on the chemical composition and total reducing sugar yield were investigated. Six pretreatments were: 1% NaOH with ultrasound for 60 min; 1% NaOH with ultrasound 100% duty; 2% NaOH with ultrasound for 60 min; 2% NaOH with ultrasound 100% duty cycle; 1% NaOH by standing in the oven at 60°C for 90 min; and 2% NaOH by standing in the oven at 60°C for 90 min. Among them, the highest cellulose content of 55.15% was obtained from bagasse by pretreating with 1% NaOH with ultrasound 100% duty cycle. It subsequently yielded the highest total reducing sugar of 36.21% (36.21 g reducing sugar/100 g substrate). The lignin content of all samples significantly decreased, but ultrasonic pretreatment increased the cellulose content. However, the best pretreatment method for each sample was different. Based on SEM analysis, the morphologies of all samples were changed after pretreatment. In addition, the increase of enzyme loading from 250 to 550 CMC U/g biomass led to more than 20% increase in the total reducing sugar. It was found that the higher enzyme loading (700 CMC U/g dried biomass) did not improve the total reducing sugar for all samples.

Keywords: Agricultural waste; alkaline; hydrolysate; pretreatment; ultrasonic

ABSTRAK

Kesan enam prarawatan ke atas lima sisa pertanian (tongkol jagung, sisa nanas, hampas tebu, jerami padi dan keladi bunting) terhadap komposisi kimia dan jumlah hasil penurunan gula telah dikaji. Enam prarawatan adalah: 1% NaOH dengan ultrabunyi untuk 60 min; 1% NaOH dengan ultrabunyi tugas 100%; 2% NaOH dengan ultrabunyi untuk 60 min; 2% NaOH dengan ultrabunyi kitar tugas 100%; 1% NaOH dengan dirian di dalam relau pada suhu 60°C selama 90 min; dan 2% NaOH dengan dirian di dalam relau pada suhu 60°C selama 90 min. Antara semua, kandungan selulosa tertinggi adalah 55.15% telah diperoleh daripada hampas tebu dengan prarawatan 1% NaOH dengan ultrabunyi kitar tugas 100%. Ia kemudiannya menghasilkan jumlah penurunan gula yang paling tinggi sebanyak 36.21% (36.21 g penurunan gula/100 g substrat). Kandungan lignin daripada semua sampel menurun dengan ketara, tetapi rawatan awal ultrasonik meningkatkan kandungan selulosa. Walau bagaimanapun, kaedah rawatan awal yang terbaik bagi setiap sampel adalah berbeza. Berdasarkan analisis SEM, morfologi semua sampel telah berubah selepas rawatan awal. Di samping itu, peningkatan muatan enzim sebanyak 250-550 CMC U/g biojisim membawa kepada 20% peningkatan dalam jumlah penurunan gula. Didapati bahawa pemuatan enzim yang tinggi (700 CMC U/g biojisim kering) tidak meningkatkan jumlah penurunan gula untuk semua sampel.

Kata kunci: Alkali; hidrolisat; prarawatan; sisa pertanian; ultrasonic

REFERENCES

Binod, P., Satyanagalakshmi, K., Sindhu, R., Janu, K.U., Sukumaran, R.K. & Pandey, A. 2012. Short duration microwave assisted pretreatment enhances the enzymatic saccharification and fermentable sugar yield from sugarcane bagasse. Renewable Energy 37(1): 109-116.

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

Chantasiri, S. & Chaiyopratum S. 2009. Water hyacinth. http://www.tistr.or.th/t/publication/page_area_show_ bc.asp?i1=86&i2=27. Accessed 21 February 2009.

Chen, M., Xia, L. & Xue, P. 2006. Enzymatic hydrolysis of corncob and ethanol production from cellulosic hydrolysate. International Biodeterioration and Biodegradation 59: 85-89.

Cheng, Y.S., Zheng, Y., Yu, C.W., Dooley, T.M., Jenkins, B.M. & VanderGheynst, J.S. 2010. Evaluation of high solids alkaline pretreatment of rice straw. Applied Biochemistry and Biotechnology 162(6): 1768-1784.

Dacera, D.M. & Babel, S. 2007. Heavy metals removal from contaminated sewage sludge by naturally fermented raw liquid from pineapple wastes. Water Science and Technology 56(7): 145-152.

Department of Alternative Energy Development and Efficiency, Thailand. 2010. Biomass Database Potential in Thailand. http://weben.dede.go.th/webmax/content/biomass-database-potential-thailand. Accessed January 3, 2016.

Eblaghi, M., Niakousari, M., Sarshar, M. & Mesbahi, G.R. 2015. Combining ultrasound with mild alkaline solutions as an effective pretreatment to boost the release of sugar trapped in sugarcane bagasse for bioethanol production. Journal of Food Process Engineering. doi:10.1111/jfpe.12220.

Filson, P.B. & Dawson-Andoh, B.E. 2009. Sono-chemical preparation of cellulose nanocrystals from lignocellulose derived materials. Bioresource Technology. 100: 2259-2264.

Kumar, P., Barrett, D.M., Delwiche, M.J. & Stroeve, P. 2009. Methods for pretreatment of lignocellulosic biomass for efficient hydrolysis and biofuel production. Industrial & Engineering Chemistry Research 48: 3713-3729.

Kunaver, M., Jasiukaitytė, E. & Čuk, N. 2012. Ultrasonically assisted liquefaction of lignocellulosic materials. Bioresource Technology 103: 360-366.

Madeleine, J.B. & Dongke, Z. 2013. Effect of ultrasound on lignocellulosic biomass as a pretreatment for biorefinery and biofuel applications. Industrial & Engineering Chemical Research 52: 3563-3580.

Martin, C., Rocha, G.J.M., Santos, J.R.A., Wanderley, C.A. & Gouveia, E.R. 2012. Enzyme loading dependence of cellulose hydrolysis of sugarcane bagasse. Quimica Nova 35: 1927-1930.

Mcintosh, S. & Vancov, T. 2010. Enhanced enzyme saccharification of Sorghum bicolor straw using dilute alkali pretreatment. Bioresource Technology 101: 6718-6727.

Miller, G. 1959. Use of dinitrisalicylic acid reagent for determination of reducing sugars. Analytical Chemistry 31: 426-429.

Mishima, D., Kuniki, M., Sei, K., Soda, S., Ike, M. & Fujita, M. 2008. Ethanol production from candidate energy crops: Water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes L.). Bioresource Technology 99(7): 2495-2500.

Nitayavardhana, S., Shrestha, P., Rasmussen, M., Lamsal, B.P., (Hans) van Leeuwen, J. & Khanal, S.K. 2010. Ultrasound improved ethanol fermentation from cassava chips in cassava-based ethanol plants. Bioresource Technology 101: 2741-2747.

Poddar, K., Mandal, L. & Banerjee, G.C. 1991. Studies on water hyacinth (Eichhornia crassipes) - Chemical composition of the plant and water from different habitats. Indian Veterinary Journal 68: 833-837.

Singh, S., Bharadwaja, S.T.P., Yadav, P.K. & Moholkar, V.S. 2014. Mechnistic investigation in ultrasound-assisted (Alkaline) delignification of Parthenium hysterophorus biomass. Industrial & Engineering Chemistry Research 53: 14241-14252.

Sluiter, A., Hames, B., Ruiz, R., Scarlata, C., Sluiter, J., Templeton, D. & Crocker, D. 2008. Determination of structural carbohydrates and lignin in biomass. Laboratory Analytical Procedure (LAP).

Sun, Y. & Cheng, J. 2008. Hydrolysis of lignocellulosic materials for ethanol production. Bioresource Technology 83(1): 1-11.

Sun, R., Lawther, J.M. & Banks, W.B. 1995. Influence of alkaline pre-treatments on the cell wall components of wheat straw. Industrial Crops and Products 4(2): 127-145.

Taherzadeh, M.J. & Karimi, K. 2008. Pretreatment of lignocellulosic wastes to improve ethanol and biogas production: A review. International Journal of Molecular Sciences 9(9): 1621-1651.

Teater, C., Yue, Z., MacLellan, J., Liu, Y. & Liao, W. 2011. Assessing solid digestate from anaerobic digestion as feedstock for ethanol production. Bioresource Technology 102: 1856-1862.

Teerapatr, S., Yuttasak, S., Nantana, B., Pichit, P. & Vorakan, B. 2012. Effect of lignocellulosic substrate and commercial cellulase loading on reducing sugar concentration for ethanol production. Journal of Food Science and Engineering 2: 149-156.

The Centre for Agricultural Information (CAI) and Regional Offices of Agricultural Economics, Agricultural Statistics of Thailand 2007. Office of Agricultural Economics. http://www. oae.go.th/pdffile/yearbook%2050/yearbook50.pdf. Accessed on 21 February 2009.

Velmurugan, R. & Muthukumar, K. 2012. Sono-assisted enzymatic saccharification of sugarcane bagasse for bioethanol production. Biochemical Engineering Journal 63: 1-9.

Zhang, Y., Fu, E. & Liang, J. 2008. Effect of ultrasonic waves on the saccharification processes of lignocellulose. Chemical Engineering and Technology 31: 1510-1515.

*Corresponding author; email: faasrpp@ku.ac.th