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Using Viscosity Reducing Enzyme as Annexing Agent in the Very High Gravity Ethanol Fermentation with Fresh Cassava(PDF)

Chinese Journal of Applied & Environmental Biology[ISSN:1006-687X/CN:51-1482/Q]

2013 03
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Using Viscosity Reducing Enzyme as Annexing Agent in the Very High Gravity Ethanol Fermentation with Fresh Cassava
(1Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China)
(2University of Chinese Academy of Sciences, Beijing 100049, China)
(3Key Laboratory of Environmental and Applied Microbiology of Chinese Academy of Sciences, Chengdu 610041, China)
(4College of Life Sciences, Sichuan University, Chengdu 610041, China)
very high gravity ethanol fermentation cassava Saccharomyces cerevisiae viscosity reducing enzyme process optimization
TQ920.6 : S533.099

This research studied the high viscosity in ethanol production from cassava with Saccharomyces cerevisiae and the use of viscosity reducing enzyme as annexing agent. It provided theoretical basis for ethanol fermentation with cassava on industry scale. Viscosity reducing enzymes optimized in our lab was used for pretreatment, which was followed by adding starch hydrolyzing enzymes in fermentation. Two hours later, the viscosity was reduced from 9×103 mPa.s to 4×102 mPa.s. In the fermentation process, the viscosity reducing enzymes decreased the viscosity to as low as 200 mPa.s in 2-4 hours, significantly increasing the liquidity of the cassava mash, which saved more energy in churning. The study of very high gravity (VHG) ethanol fermentation by S. cerevisiae found the following optimal conditions for VHG fermentation: the total sugar in the cassava root as 24%; viscosity reducing enzyme dosage as 1 g/kg; the best nitrogen source as carbamide when using the simultaneous saccharification and fermentation process; and the dosage of N as 0.06% of the total fermentation mash. Accordingly, the final ethanol concentration was up to 115.57 g/kg, with the ethanol efficiency 91.92% and ethanol productivity 4.81 g kg-1 h-1 after 24 h. When the fermentation scale was expanded to 5 L, and the ethanol productivity was 4.78 g kg-1 h-1.


1 薛万伟, 党选举, 李鑫. 木薯酒精发酵工艺的研究[J]. 酿酒, 2005, 32 (4): 56-60 [Xue WW, Dang XJ, Li X. Study on the technology of cassava ethanol fermentation [J]. Liquor Making, 2005, 32 (4): 56-60]
2 Adeniyi OD, Kove AS, Abdulkareem AS, Chukwudozie C. Ethanol fuel production from cassava as a substitute for gasoline [J]. J Dispersion Sci Technol, 2007, 28: 501-504
3 Wang D, Bean S, McLaren J, Seib P, Madl R, Tuinstra M, Shi Y, Lenz M, Wu X, Zhao R. Grain sorghum is a viable feedstock for ethanol production [J]. J Ind Microbiol Biotechnol, 2008, 35 (5): 313-320
4 Ingledew WM, Thomas KC, Hynes SH, McLeod JG. Viscosity concerns with rye mashes used for ethanol production [J]. Cereal Chem, 1999, 76 (3): 459-464
5 Zhang L, Chen Q, Jin YL, Xue HL, Guan JF, Wang ZY, Zhao H. Energy-saving direct ethanol production from viscosity reduction mash of sweet potato at very high gravity (VHG) [J]. Fuel Process Technol, 2010, 91 (12): 1845-1850
6 Maldonado MC, Strasser de Saad AM. Production of pectinesterase and polygalacturonase by Aspergillus niger in submerged and solid state systems [J]. Ind Microbiol Biotechnol, 1998, 20 (1): 3438
7 Zaidul ISM, Norulain NAN, Omar AKM, Yamauchi H, Noda T. RVA analysis of mixtures of wheat flour and potato, sweet potato, yam, and cassava starches [J]. Carbohyde Polym, 2007, 69 (4): 784-791
8 伍彦华, 张家伟, 韩宏明, 盘柳萍. 木薯酒精发酵废液回用的工艺技术探[J]. 广西轻工, 2010 (5): 36-38
9 Mendes-Ferreira A, del Olmo M, García-Martínez J, Jiménez-Martí E, Leão C, Mendes-Faia1 A, Pérez-Ortín JE. Saccharomyces cerevisiae signature genes for predicting nitrogen deficiency during alcoholic fermentation [J]. Appl Environ Microbiol, 2007, 73 (16): 5363-5369
10 Jones AM, Ingledew WM. Fuel alcohol production: optimization of temperature for efficient very high gravity fermentation [J]. Appl Environ Microbiol, 1994, 60 (3): 1048-1051


Last Update: 2013-06-20