Azlin Suhaida Azmi, Nurlisa Yusuf, Dzun Noraini Jimat, Noor Illi Mohamad Puad


Production of lactic acid and ethanol from inedible cassava starch and leaves was investigated. Prior to fermentation, hydrolysis of the starch and leaves was conducted. Hydrolysis was optimized by manipulating at three levels each four particular factors, namely acid concentration, starch concentration, temperature, and reaction time. Maximum glucose yield of 0.96 g/g was obtained when 2.5% (w/v) of cassava leaves with 2.5% (w/v) of starch was hydrolyzed using 0.20 M of nitric acid at 160oC of temperature for 10 min. The potential of hydrolyzed cassava starch and leaves was then investigated for lactic acid production using fungal Rhizopus sp. The fermentation process was then conducted in shake flask by varying four factors at three levels each. Maximum lactic acid and ethanol yields of 0.95 g/g and 0.52 g/g, respectively, were achieved at different optimum conditions.  Lactic acid production was found to be linked to a decrease in ethanol production. Design Expert v6.0.8 was used to aid in the design of the experiment using Taguchi’s methodology.

Full Text:


View Counters:

Abstract - 201 PDF - 275


Wee Y-J, Kim J-N, Ryu H-W. Biotechnological production of lactic acid and its recent applications. Food Technol. Biotechnol. 2006,44,163-72.

Fregene M, Puonti-Kaerlas J. Cassava biotechnology. Cassava: Biology, production and utilization. 2002,10,179-207.

Lim KK. Project Consultant from Kibartek Sdn Bhd. 2011.

Fasuyi AO. Nutrient composition and processing effects on cassava leaf (Manihot esculenta, Crantz) antinutrients. Pak J Nutr. 2005,4,37-42.

Ravindran V. Preparation of cassava leaf products and their use as animal feeds. Roots, tubers, plantains and bananas in animal feeding FAO Animal Production and Health Paper. 1992.

Cereda M, Mattos M. Linamarin: the toxic compound of cassava. J. Venomous Anim. Toxins. 1996,2,06-12.

Taskin M, Ortucu S, Unver Y, Arslan NP, Algur OF, Saghafian A. L-lactic acid production by Rhizopus oryzae MBG-10 using starch-rich waste loquat kernels as substrate. Starch - Stärke. 2013,65,322-9.

Zhang ZY, Jin B, Kelly JM. Production of lactic acid from renewable materials by Rhizopus fungi. Biochem. Eng. J. 2007,35,251-63.

Bulut S, Elibol M, Ozer D. Effect of different carbon sources on l(+) -lactic acid production by Rhizopus oryzae. Biochem. Eng. J. 2004,21,33-7.

Park EY, Anh PN, Okuda N. Bioconversion of waste office paper to l (+)-lactic acid by the filamentous fungus Rhizopus oryzae. Bioresour. Technol. 2004,93,77-83.

Soccol C, Marin B, Raimbault M, Lebeault J-M. Potential of solid state fermentation for production of L (+)-lactic acid by Rhizopus oryzae. Appl. Microbiol. Biotechnol. 1994,41,286-90.

Azmi AS, Ngoh CG, Mel M. Prediction of significant factors in the production of ethanol by ragi tapai co-culture using Taguchi methodology. Afr. J. Biotechnol. 2013,10,18833-41.

Widiasa IN, Wenten IG. Saccharification of native cassava starch at high dry solids in an enzymatic membrane reactor. REAKTOR. 2009,12,129–36.

Xiao Z, Wu M, Beauchemin M, Groleau D, Lau PC. ORIGINAL RESEARCH: Direct fermentation oftriticale starch to lactic acid by Rhizopus oryzae. Ind. Biotechnol. 2011,7,129-34.

Büyükkileci AO, Hamamcı H, Yucel M. Lactate and ethanol productions by Rhizopus oryzae ATCC 9363 and activities of related pyruvate branch point enzymes. J. Biosci. Bioeng. 2006,102,464-6.

Kossen N. The morphology of filamentous fungi. History of Modern Biotechnology II: Springer, 2000, p. 1-33.

Liao W, Liu Y, Frear C, Chen S. A new approach of pellet formation of a filamentous fungus–Rhizopus oryzae. Bioresour. Technol. 2007,98,3415-23.

Wu X, Jiang S, Liu M, Pan L, Zheng Z, Luo S. Production of L-lactic acid by Rhizopus oryzae using semicontinuous fermentation in bioreactor. J. Ind. Microbiol. Biotechnol. 2011,38,565-71.

Meussen BJ, de Graaff LH, Sanders JP, Weusthuis RA. Metabolic engineering of Rhizopus oryzae for the production of platform chemicals. Appl. Microbiol. Biotechnol. 2012,94,875-86.

Naranong N, Poocharoen D. Production of L-Lactic Acid from Raw Cassava Starch by Rhizopus oryzae NRRL 395. The Kasetsart J (Nat Sci). 2001,35,164-70.

Nasir NAM, Kamalbahrin MAM, Mohamad N, Anuar H, Mel M, Othman R. Effect of Rhizopus oryzae fermentation on kenaf-based polylactic acid’s Monomer. IIUM Eng. J. 2011,12.

Tanyıldızı MŞ, Bulut Ş, Selen V, Özer D. Optimization of lactic acid production with immobilized Rhizopus oryzae. Afr. J. Biotechnol. 2012, 11,8546-52.

Huang LP, Jin B, Lant P, Zhou J. Simultaneous saccharification and fermentation of potato starch wastewater to lactic acid by Rhizopus oryzae and Rhizopus arrhizus. Biochem. Engin. J. 2005, 23, 265-76.

Thongchul N, Navankasattusas S, Yang S-T. Production of lactic acid and ethanol by Rhizopus oryzae integrated with cassava pulp hydrolysis. Bioprocess and biosystems engineering. 2010; 33: 407-16.

Huang LP, Jin B, Lant P, Zhou J. Biotechnological production of lactic acid integrated with potato wastewater treatment by Rhizopus arrhizus. J. Chem. Technol. Biotechnol. 2003,78,899-906.

Skory CD. Induction of Rhizopus oryzae pyruvate decarboxylase genes. Curr. Microbiol. 2003,47,0059-64.


  • There are currently no refbacks.

ISSN:    1511-788X
E-ISSN: 2289-7860

Creative Commons License
IIUM Engineering Journal by is licensed under a Creative Commons Attribution 4.0 International License