Huynh Xuan Phong * , Nguyen Ngoc Thanh , Pham Thieu Quan and Ngo Thi Phuong Dung

* Correspondence: Huynh Xuan Phong (email:

Main Article Content


Bioethanol is an environmentally friendly fuel and renewable source in many industrial applications. Cocoa pod is an abundant agro-waste source and can be used for bioethanol production because this lignocellulosic material has high content of cellulose. The aim of this study was to investigate the ability for bioethanol production from cocoa pod hydrolysate. Four strains of Saccharomyces cerevisiae (2.1, B3, D3, D4) were examined for bioethanol production from cocoa pod hydrolysate with the initial inoculation levels at 102, 104, 106, 107 cells/mL. The fermenting medium was tested with the reducing sugar concentration in a range of 5.0, 6.0, 7.0, and 8.6% (w/v) and pH value at 4.5, 5.0, 5.5 and 6.0. The fermentation conditions were designed at different temperatures (25, 30, 37°C) and times (3, 5, 7, 9 days). The results showed that the suitable yeast strain for ethanol fermentation was S. cerevisiae D3 with the inoculum level of 106 cells/mL. The ethanol concentrations of 4.14-4.19% (w/v) were achieved after 9 days at 30°C from cocoa pod hydrolysate contained 8.6% (w/v) of reducing sugar with initial pH at 5.5, the sugar consumption efficiencies were 97.54-97.56%. These outputs indicated the promising feasibility of bioethanol production from such waste material source of cocoa pods.
Keywords: Cocoa, cocoa pod hydrolysate, ethanol fermentation, Saccharomyces cerevisiae, Theobroma cacao

Article Details


Adeleke, E.O., Bridget, O.O., Isaac, O.A., Mufutau, K.B., 2012. Purification and characterization of a cellulase obtained from cocoa (Theobroma cacao) pod-degrading Bacillus coagulans co4. Turkish Journal of Biochemistry. 37(2): 222-230.

Bennett, C., 1971. Spectrophotometric acid dichromate method for the determination of ethyl alcohol. The American Journal of Medical Technology. 37(6): 217.

Duku, M.H., Gu, S., Hagan, E.B., 2011. A comprehensive review of biomass resources and biofuels potential in Ghana. Renewable and Sustainable Energy Reviews. 15(1): 404-415.

Galazzo, J.L., Bailey, J.E., 1990. Fermentation pathway kinetics and metabolic flux control in suspended and immobilized Saccharomyces cerevisiae. Enzyme and Microbial Technology. 12(3): 162-172.

Hoa, N.V., 2007. Overview: the present and future cocoa plantation and production in Vietnam. Substantial Cocoa Development in Vietnam Workshop. Ben Tre, Vietnam (in Vietnamese).

Laluce, C., Schenberg, A.C.G., Gallardo, J.C.M., Coradello, L.F.C., Pombeiro-Sponchiado, S.R., 2012. Advances and developments in strategies to improve strains of Saccharomyces cerevisiae and processes to obtain the lignocellulosic ethanol - A Review. Applied Biochemistry and Biotechnology. 166(8): 1908-1926.

Lam, F.H., Ghaderi, A., Fink, G.R., Stephanopoulos, G., 2014. Engineering alcohol tolerance in yeast. Science. 346(6205): 71-75.

Orlandi, I., Ronzulli, R., Casatta, N., Vai, M., 2013. Ethanol and acetate acting as carbon/energy sources negatively affect yeast chronological aging. Oxidative Medicine and Cellular Longevity. (ID 802870): 1-10.

Pampulha, M.E., Loureiro-Dias, M.C., 1989. Combined effect of acetic acid, pH and ethanol on intracellular pH of fermenting yeast. Applied Microbiology and Biotechnology. 31(5-6): 547-550.

Pham, L.D., 2009. Industrial Yeasts. Science and Technology Publishing House, Hanoi, Vietnam (in Vietnamese).

Phong, H.X., Quan, P.T. Quan, Thanh, N.N., Dung, N.T.P., 2015. Study on the possibility of hydrolysis of cocoa pod for ethanol fermentation. Dong Thap University Journal of Science. 16: 92-96 (in Vietnamese).

Stanley, D., Bandara, A., Fraser, S., Chambers, P.J, Stanley, G.A., 2010. The ethanol stress response and ethanol tolerance of Saccharomyces cerevisiae. Journal of Applied Microbiology. 109(1): 13-24.

Tasun, K., Chose, P., Ghen, K., 1970. Sugar determination of DNS method. Biotechnology and Bioengineering. 12: 921.

Thomsen, S.T., Kádár, Z., Schmidt, J.E., 2014. Compositional analysis and projected biofuel potentials from common West African agricultural residues. Biomass and Bioenergy. 63: 210-217.

Trumbly, R.J., 1992. Glucose repression in the yeast Saccharomyces cerevisiae. Molecular Microbiology. 6(1): 15-21.

van Maris, A.A., Abbott, D.A., Bellissimi, E., van den Brink, J., Kuyper, M., Luttik, M.H., Wisselink, H.W., Scheffers, W.A., van Dijken, J.P., Pronk. J.T., 2006. Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae: Current status. Antonie van Leeuwenhoek. 90(4): 391-418.

You, K.M., Rosenfield, C.L., Knipple, D.C., 2003. Ethanol tolerance in the yeast Saccharomyces cerevisiae is dependent on cellular oleic acid content. Applied and Environmental Microbiology. 69(3): 1499-1503.

Wallace-Salinas, V., Gorwa-Grauslund, M.F., 2013. Adaptive evolution of an industrial strain of Saccharomyces cerevisiae for combined tolerance to inhibitors and temperature. Biotechnology for Biofuels. 6: 151-151.