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BY-NC-ND 3.0 license Open Access Published by De Gruyter Open Access August 18, 2015

Bioconversion of degraded husked sorghum grains to ethanol

  • Muhammad Nasidi , Reginald C. Agu , Yusuf Deeni , Idris Bala Giginyu and Graeme Walker
From the journal Bioethanol

Abstract

Efficient starch saccharification is an essential step towards achieving improved ethanol yields by fermentation. Sorghum grains are important starch sources for bioconversion to ethanol. In the present study, disease degraded (spoilt) husked grains from Nigerian sorghum cultivars were obtained from field sites and subjected to bioprocessing to ethanol. The crude husked grains (comprising husks, spikelet, awn, rachis and pubescence materials) were hammer milled and each meal separately mashed with enzyme cocktails comprising amylase, glucanase and protease enzymes. The saccharified worts obtained were then fermented with the yeasts, Saccharomyces cerevisiae and Pichia stipitis (aka Scheffersomyces stipitis), without exogenous nutrient supplementation. Sugars liberated during mashing were determined and it was found that enzymatic hydrolysis of milled sorghum grains was effective in yielding favourable levels of fermentable sugars up to 70g sugar/100g substrate with one particular cultivar (KSV8). Ethanol and carbon dioxide production was measured from subsequent trial fermentations of the sorghum mash and it was found that S. cerevisiae produced ethanol levels equating to 420 L/t that compares very favourably with yields from wheat and barley. Our findings show that crude degraded sorghum grains represent favourable low-cost feedstocks for bioconversion to ethanol with reduced energy input and without additional costs for nutrient supplementation during fermentation. Consequently, our results suggest some economic benefits could be derived from spoilt or degraded sorghum grains.

References

[1] Nasidi M., Akunna J., Deeni Y., Blackwood D., Walker G., Bioethanol in Nigeria: comparative analysis of sugarcane and sweet sorghum as feedstock sources, J. Energy Environ. Sci., 2010, 3, 1447-1457. 10.1039/c0ee00084aSearch in Google Scholar

[2] Kothari D.P., Singal K.C., Ranjan R., Renewable energy sources and emerging technologies, 2nd ed., PHI Learning, New Delhi, 2012. Search in Google Scholar

[3] Walker G.M., Fuel alcohol: Current production and future challenges, J. Inst. Brew., 2011,1, 3–22. 10.1002/j.2050-0416.2011.tb00438.xSearch in Google Scholar

[4] Nasidi M., Deeni Y., Agu R. Walker G., Fermentation of stalk juices from different Nigerian sorghum cultivars to ethanol, J. Bioethanol, 2013, 1, 20-27. 10.2478/bioeth-2013-0003Search in Google Scholar

[5] Etuk E.B., Ifeduba A.V., Okata U.E., Chiaka I., Okoli, Ifeanyi C., Okeudo N.J., Esonu B.O., Udedibie A.B.I., Moreki, J.C., Nutrient composition and feeding value of sorghum for livestock and poultry: a review., J. Anim. Sci. Adv., 2012, 6, 510-524. Search in Google Scholar

[6] United State Department of Agriculture, Nigeria food security update: Famine early warning systems network (FEWS.NET), USAID, 2009, www.fews.net/foodsecurityscale Search in Google Scholar

[7] Ismaila U., Gana A.S., Tswanya N.M., Dogara, Cereals production in Nigeria: Problems, constraints and opportunities for betterment, Afri. J. Agric. Res., 2010, 5, 1341-1350. Search in Google Scholar

[8] Agu R.C., Bringhurst T.A., Brosnan J.M., Production of grain whisky and ethanol from wheat, maize and other cereals, J. Inst. Brew., 2006, 4, 314-323. 10.1002/j.2050-0416.2006.tb00737.xSearch in Google Scholar

[9] Showemimo F.A., Grain yield response and stability indices in sorghum (sorghum bicolor (L.) Moench), J. Agric. Biol., 2007, 2, 68-73. Search in Google Scholar

[10] Ijasan B., Goodfellow V., Bryce J.H., Bringhurst T.A., Brosnan J.M., Jack F.R., Agu R.C., Quality Assessment of a Sorghum Variety Malted Commercially under Tropical Conditions and Controlled Tropical Temperatures in the Laboratory, J. Inst. Brew., 2011, 2, 206–211. 10.1002/j.2050-0416.2011.tb00462.xSearch in Google Scholar

[11] Ng’uni D., Geleta M., Johansson E., Fatih M., Bryngelsson T., Characterization of the Southern African sorghum varieties for mineral contents: Prospects for breeding for grain mineral dense lines, African Journal of Food Science, 2011, 7, 436-445. Search in Google Scholar

[12] Yago J.I., Roh J., Bae S., Yoon Y., Kim H., Nam M., The Effect of Seed-borne mycoflora from sorghum and foxtail millet seeds on germination and disease transmission, Journal of Mycobiology, 2011, 3, 206-218. 10.5941/MYCO.2011.39.3.206Search in Google Scholar

[13] Panchal V.H., Dhale D.A., Isolation of seed-borne fungi of sorghum (Sorghum vulgarepers.), Journal of Phytology, 2011, 12, 45-48. Search in Google Scholar

[14] Ginovart M., Prats C., Portell X., Silbert M., Analysis of the effect of inoculum characteristics on the first stages of a growing yeast population in beer fermentations by means of an individual-based model, J. Industr. Microbiol. Biotech., 2011, 38, 153-165. 10.1007/s10295-010-0840-4Search in Google Scholar

[15] Youssef A. M., Extractability, fractionation and nutritional value of low and high tannin sorghum proteins, J. Food Chemi., 1998, 63, 325-329. 10.1016/S0308-8146(98)00028-4Search in Google Scholar

[16] de Mesa-Stonestreet N.J., Alavi S., Bean S.R., Sorghum proteins: The concentration, isolation, modification, and food applications of kafirins, J. Food Science, 2010, 5, R90-R104. 10.1111/j.1750-3841.2010.01623.xSearch in Google Scholar PubMed

[17] Aldaeus F., Sjoholm E., Round Robins of lignin samples Part 1: Lignin content, Innventia Report No.: IR 108, 2011, http:// ir108_costfp0901_pr1lignincontent.pdf Search in Google Scholar

[18] Zhang G., Hamaker B.R., Low a-amylase starch digestibility of cooked sorghum flours and the effect of protein, J. Cereal Chemistry, 1998, 75, 710-713. 10.1094/CCHEM.1998.75.5.710Search in Google Scholar

[19] Osman A., Coverdale S.M., Ferguson R., Watson K., Fox G., Hamilton E., de Jersey A., What causes low barley proteins modification and low wort free amino nitrogen - Proteins or Proteinases, In: Proceedings of the 10th Australian barley technical symposium (16-20 September 2001, Canberra, ACT., Australia), Canberra, 2001, T4. Search in Google Scholar

[20] Goldammer T., The Brewers’ Handbook: the Complete Book to Brewing Beer, Apex, New York, 2008 Search in Google Scholar

[21] Van Hung P., Maeda T., Morita N., Waxy and high-amylose wheat starches and flours characteristics, functionality and application, Trends in Food Science & Technology, 2006, 17, 448–456. 10.1016/j.tifs.2005.12.006Search in Google Scholar

[22] Lyumugabe F., Gros J., Nzungize J., Bajyana E., Thonart P., Characteristics of African traditional beers brewed with sorghum malt: a review. Biotechnology, Agronomy, Society and Environment, 2012, 4, 509-530. Search in Google Scholar

[23] Wong J.H., Lau T., Cai N., Singh J., Pedersen J.F., Vensel W.H., Hurkman W.J., Wilson J.D., Lemaux P.G., Buchanan B.B., Digestibility of protein and starch from sorghum (Sorghum bicolor) is linked to biochemical and structural features of grain endosperm, J. Cereal Science, 2009, 49, 73-82. 10.1016/j.jcs.2008.07.013Search in Google Scholar

[24] Caspeta L., Shoaie S., Agren R., Nookaew I., Nielsen J., Genome-scale metabolic reconstructions of Pichia stipitis and Pichia pastoris and in silico evaluation of their potentials, J. BMC Systems Biology, 2012, 24, 1-14. 10.1186/1752-0509-6-24Search in Google Scholar

[25] Thomas K.C., Ingledew W.M., Fuel alcohol production: effects of free amino nitrogen on fermentation of very-high-gravity wheat mashes, Applied and Environmental Microbiology, 1992, 56, 2046-2050. 10.1128/aem.56.7.2046-2050.1990Search in Google Scholar

[26] Jeffries T.W., Jin Y., Ethanol and thermotolerance in the bioconversion of xylose by yeasts, Advances in Applied Microbiology, 2009, 47, 221-268. 10.1016/S0065-2164(00)47006-1Search in Google Scholar

[27] Rouhollah H., Iraj N., Giti E., Sorah A., Mixed sugar fermentation by Pichia stipitis, Sacharomyces cerevisiae, and an isolated xylose fermenting Kluyveromyces marxianus and their cocultures, African Journal of Biotechnology, 2007, 9, 1110-1114. Search in Google Scholar

[28] Lee W.J., Yoon J.R., Park K.J., Chung K.M., Fermentation of corn and wheat with supplementation of inactive dry brewer’s yeast, J. Ameri. Soci. Brew. Chem., 2000, 58, 155-159. 10.1094/ASBCJ-58-0155Search in Google Scholar

[29] Agbogbo F.K., Coward-Kelly G., Torry-Smith M., Wenger K.S., Fermentation of glucose/xylose mixtures using Pichia stipitis. Process Biochemstry Journal, 2006, 41, 2333–2336. 10.1016/j.procbio.2006.05.004Search in Google Scholar

[30] Hotz C., Gibson R.S., Traditional food-processing and preparation practices to enhance the bioavailability of micronutrients in plant-based diets, The Journal of Nutrition, 2007, 137, 1097-1100. 10.1093/jn/137.4.1097Search in Google Scholar PubMed

[31] Gutierrez-Rivera C., Mendoza G.D., Pinos-Rodriguez R., Aranda E., Ricalde R., Mirande L.A., Effect of Storage Time and Processing Temperature of Grains With Added Amylolytic Enzymes on In situ Ruminal Starch Digestion, Journal of Applied Animal Research, 2011, 1, 39-44. 10.1080/09712119.2005.9706534Search in Google Scholar

[32] Wu X., Stagenborg S., Propheter J.L., Rooney W.L., Yu J., Wang D., Features of sweet sorghum juice and their performance in ethanol fermentation, Journal of Industrial Crops and Products, 2010, 13, 164-170. 10.1016/j.indcrop.2009.10.006Search in Google Scholar

[33] Sheorain V, Banka R, Chavan M., Ethanol production from sorghum, In: Chandrashekar A., Bandyopadhyay R., Hall A.J., (Eds.), Proceedings of an international consultation, (18-19 May 2000, Andhra Pradesh, India), ICRISAT, Andhra Pradesh, 2000, 228-239. Search in Google Scholar

[34] Ogbonna A.C., Current developments in malting and brewing trials with sorghum in Nigeria: A Review, J. Inst. Brew., 2011, 3, 394-400. 10.1002/j.2050-0416.2011.tb00485.xSearch in Google Scholar

[35] Okolo B.N., Moneke A.N., Ezeogu L.I. Ire F.S., The effects of calcium regulation of endosperm reserve protein mobilization of the Nigeria sorghum cultivars, ICSV 400 and KSV 8 during malting, J. Afri. Biotech., 2011, 27, 5355-5369. Search in Google Scholar

[36] Serna-Saldivar S.R.O., Cereal grains: properties, processing and nutritional attributes (Food preservation technology), The Food Preservation Technology Series, 1st ed. CRC, New York, 2011 Search in Google Scholar

[37] Adeteju A.O., Ayoade A.M., Obafemi A., Moisture Dependance of Some Properties of Malted Sorghum Grains, American- Eurasian Journal of Agricultural & Environmental Sciences, 2012, 3, 365-368. Search in Google Scholar

Received: 2014-9-1
Accepted: 2015-2-10
Published Online: 2015-8-18
Published in Print: 2016-1-1

© 2015 Muhammad Nasidi et al.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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