Production of Ethanol and Biomass from Rice Husk Using Cultures of Aspergillus flavus, Aspergillus eamarii and Saccharomyces cerevisiae

Onwuakor Chijioke E^1, , Hans-Anukam Uzunma² and Uzokwe Munachi J¹

¹Department of Microbiology, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria

²Department of Microbiology/Biochemistry, Federal Polytechnic, Nekede, Imo State, Nigeria

Cite this paper:
Onwuakor Chijioke E, Hans-Anukam Uzunma and Uzokwe Munachi J. Production of Ethanol and Biomass from Rice Husk Using Cultures of Aspergillus flavus, Aspergillus eamarii and Saccharomyces cerevisiae. American Journal of Microbiological Research. 2017; 5(4):86-90. doi: 10.12691/ajmr-5-4-3

Abstract

Microbial degradation/conversion of agricultural/industrial wastes to useful bio-products such as bioethanol has become increasingly a popular alternative to gasoline worldwide and has been proven to be useful in many industrial and pharmaceutical processes. In this work, microbial hydrolysis of rice husk into fermentable sugars using Aspergillus flavus and Aspergillus eamarii and subsequent fermentation of sugars to ethanol was achieved using Saccharomyces cerevisiae. The rice husks were ground to fine powder and microbially hydrolyzed by incubating with Aspergillus flavus and Aspergillus eamarii in peptone water for 7 days. Determination of reducing sugar using Fehlings’ reagents confirmed the presence of fermentable sugar in both media. Approximately 6.89° Brix in Aspergillus flavus medium was optimized to 24.41° Brix while 7.12° Brix in Aspergillus eamarii was optimized to 24.10° Brix by adding 300g of sucrose and then fermented to ethanol using Saccharomyces cerevisiae isolated from palm wine at room temperature. The results showed a reduction in pH (6.5-4.1 and 6.8-4.1), an increase in temperature (28-30°C and 28-30°C), increase in percentage titratable acidity (0.33-2.96% and 0.27-2.90%), significant increase in alcohol content (0.00-14.89% and 2.42-14.47%), increase in biomass (0.00-2.16g/l and 0.00-2.08g/l) and decrease in specific gravity (1.112-1.005 and 1.114-1.007) in Aspergillus flavus and Aspergillus eamarii media respectively over a period of 7 days of fermentation. Aspergillus flavus and Aspergillus eamarii hydrolysates yielded 14.89% and 14.47% ethanol respectively after distillation. The results of the experiment conducted shows that rice husk and other cellulosic agricultural wastes could be potential substrates which can be exploited by industries for production of bioethanol and other biotechnological products.

Keywords:
rice husk ethanol biomass Aspergillus saccharomyces hydrolysis

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]	Chandel, A.K., Chan, E.S., Rudravaram, R.M., Narasu, L.L., Rao, V. and Ravindra, P “Economics and environmental impact of bioethanol production technologies: an appraisal,” Biotechnology and Molecular Biology Review, 2 (1), 14-32, Feb. 2007.
[2]	Rabelo, S.C., Carrere, H., MacielFilho, R. and Costa, A.C. “Production of Bioethanol, Methane and Heat from Sugarcane Bagasse in a Biorefinery Concept,” Bioresource Technology, 102, 7887-7895. 2011.
[3]	Mosier, N., Wyman, C., Dale, B., Elander, R., Lee, Y.Y. and Holtzapple, M. “Features of promising technologies for pretreatment of lignocellulosic biomass,” Bioresource Technology, 96: 673-686. 2005.
[4]	FAOSTAT, “Rice”. Available at http://faostat.fao.org/site/339/default.aspx. 2015. Retrieved November 14, 2016.
[5]	Binod, P., Sindhu, R., Singhania, R.R., Vikram, S., Devi, L., Nagalakshmi, S., Kurien, N., Sukumaran, R.K., and Pandey, A. “Bioethanol from Rice Husk: An Overview,” Bioresource Technology, 101, 4767-4774. 2010.
[6]	James, C.S. Experimental methods on analytical chemistry of foods. Chapman and Hull, New York, 1995, 114-116.
[7]	Onwuka, G.I. Food analysis and Instrumentation: Theory and Practice. Naphthalein Prints, Lagos, 2005, 39-42.
[8]	Mbajiuka, C.S., Omeh, S.F. and Ezeja, M.I. “Fermentation of Sorghum using Yeast (Saccharomyces cerevisiae) as starter culture for Burukutu Production,” Continental Journal of Biological Sciences. 3, 63-74. 2010.
[9]	Patel, S.J. Onkarappa, R. and Shobha, K.S. “Study of Ethanol production from Fungal pretreated wheat and rice straw,” The Internet Journal of Microbiology, 4 (1), 1-5. 2006.
[10]	Sun, Y. and Cheng, J. “Hydrolysis of lignocellulosic materials for ethanol production, A review,” Bioresource Technology, 83, 1-11. 2002.
[11]	Hough, J.S., Briggs, D.E., Steven, R. and Young, T.W. Hopped Wort and Beer In: Malting and Brewing Science, Vol. 2.Chapman and Hall, 1997. 580-785.
[12]	Idise, O.E. “Studies on wine production from coconut (Cocos nucifera),” Journal of Brewing and Distilling, 2 (5), 69-74. Dec. 2011.
[13]	Karimi, K., Emtiazi, G. and Taherzadeh, M.J. “Ethanol production from dilute-acid pretreated rice straw by simultaneous saccharification and fermentation with Mucor indicus, Rhizopus oryzae, and Saccharomyces cerevisiae,” Enzyme Microbiology Technology, 40, 138-144. 2006.
[14]	Azuma, J., Tanaka, F. and Koshijima, T. “Enhancement of enzymatic susceptibility of lignocellulosic wastes by microwave irradiation,” Journal of Fermentation Technology, 62, 377-384. 1984.
[15]	Taouda1, H, Chabir1, R., Aarab, L., Miyah, Y. Errachidi, F. “Biomass and bio-ethanol production from date extract,” Journal of Materials and Environmental Sciences, 8 (9), 3093-3098. 2017.
[16]	Mbajiuka, C.S., Ifediora, A.C., Onwuakor, C.E., and Nwokoji, L.I. “Fermentation of pods of cocoa (Theobroma cacao L) using palm wine yeasts for the production of alcohol and biomass,” American Journal of Microbiological Research, 3, 80-84. 2015.
[17]	Reed, G. Prescott and Dunn’s Industrial Microbiology 4th Edition. CBS Press, New Dehli, 2004, 568-849.