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Introductionഀ Lignocellulose biorefining is a worldwide challenge for chemical and biochemical processes. The bioconversion of renewable materials into chemical and fuel ethanol involves three steps: pretreatment, enzymatic hydrolysis and fermentation. The first step represents the major barrier to commercialization of ethanol due the costs of the pretreatment. ഀ In the recent time, various research initiatives have been developed to find a way of reducing the production costs associated with the production of bioethanol from lignocellulose materials. One of these initiatives is to use classical and precision breeding of feedstocks for preferred characteristics, such as, higher biomass yields per hectare and physico-chemical composition that is amenable to pretreatment-hydrolysis. Any attempt to change the structure matrix of the lignocellulose biomass to make it easier for enzyme attack and reduce the pretreatment cost will be a step forward for the development of large scale, especially if this can be combined with higher biomass yields per hectare, to maximize energy production per land used.ഀ Results and Conclusionsഀ In the present work, the bagasse residues from milling of different varieties of sweet sorghum and sugarcane were evaluated to establish how they respond to diluted acid treatment. The use of bagasse from a variety that is more susceptible to dilute acid pretreatment can reduce input costs to the process by reducing the amount acid, reaction time as well as the energy needed to break the structure of the biomass and release the sugar. In turn, low acid concentration and low temperature can decrease the potential for reduced sugar yield through the formation of sugar degradation products which also inhibit fermentation. Significant improvements in the yield of sugar from hydrolysis of pretreated bagasse, when using preferred varieties were observed. This provides substantial evidence for the use of rational feedstock development to maximise bio-ethanol production per hectare, by using the complete sugarcane or sweet sorghum plant.ഀ Thermo-chemical pretreatment of lignocellulosic biomass also results in the production of toxic by-products resulting of sugar degradation. Furfural and HMF are typically present in the greatest concentrations and inhibit microbial metabolism resulting in decreased ethanol yield and productivity. Therefore, the development of yeast strains tolerant to these by-products is required to enhance ethanol production. In this work, a recombinant xylose-utilizing Saccharomyces cerevisiae strain D5A+ was subjected to one round of random mutagenesis through exposure to the chemical mutagen EMS. Significant improvements in fermentation performance and inhibitor resistance could be achieved by random mutagenesis, selection and evolutionary adaptation of the yeasts.ഀ These represent examples of the application of biotechnologies to significantly improve the efficiency of cellulosic ethanol production from energy crops.ഀ Author publicationsഀ 1. Amigun B, JF Görgens, JH Knoetze (2010). Biomethanol production from gasification of non-woody plants in South Africa: Optimum scale and economic performance. Energy Policy 38: 312–322 ഀ 2. Lalloo R, D Maharajh, J Görgens, N Gardiner (2010). A downstream process for production of a viable and stable Bacillus cereus aquaculture biological agent. Applied Microbiology and Biotechnology 86(2): 499-508ഀ 3. Vena PF, JF Görgens and T. Rypstra (2010). Hemicelluloses Extraction from Giant Bamboo prior to Kraft and Soda AQ Pulping to Produce Paper Pulps, Value-added Biopolymers and Bio-ethanol. Cellulose Chemistry and Technology 44 (4-6): 153-163 ഀ 4. Van Zyl WH, SH Rose, KM Trollope, JF Görgens (2010). Fungal β-mannanases: Mannan Hydrolysis, Heterologous production and Biotechnological applications. Process Biochemistry 45(8): 1203-1213ഀ 5. Bredenkamp A, H Velankar, WH van Zyl, JF Görgens (2010). Effect of Dimorphic Regulation on Heterologous Glucose Oxidase Production by Mucor circinelloides. Yeast 27 (10): 849–860.ഀ 6. Lalloo, R., Moonsamy, G., Ramchuran, S., Görgens, J., Gardiner, N. 2010. Competitive exclusion as a mode of action of a novel Bacillus cereus aquaculture biological agent. Letters in Applied Microbiology 50 (6), pp. 563-570 ഀ 7. Kotzé L, JJ Smith, R. den Haan, WH van Zyl and JF Görgens (2011). Expression of human papillomavirus type 16 (HPV16) L1 protein in Pichia pastoris. African Journal of Biotechnology Vol. 10 (2), pp. 214-219ഀ 8. Carrier M, T Hugo, J Görgens, JH Knoetze (2011). Comparison of slow and vacuum pyrolysis of sugar cane bagasse. Journal of Analytical and Applied Pyrolysis 90 (1), pp. 18-26ഀ 9. Van Zyl WH, AFA Chimphango, R den Haan, JF Görgens, P Chirwa (2011). Next generation cellulosic ethanol technologies and their contribution to a sustainable Africa. Interface Focus 1:196-211ഀ 10. Aboyade AO, TJ Hugo, M Carrier, EL Meyer, R Stahl, JH Knoetze, JF Görgens. 2011. Non-isothermal kinetic analysis of corn cobs and sugar cane bagasse pyrolysis. Thermochimica Acta 517: 81–89ഀ 11. Leibbrandt NH, JH Knoetze, JF Görgens. 2011. Comparing biological and thermochemical processing of sugarcane bagasse: An energy balance perspective. Accepted for publication in Biomass and Bioenergy ഀ 12. García-Aparicio M, K Trollope, L Tyhoda, D Diedericks, J Görgens. (2011). Evaluation of Triticale Bran as Raw Material for Bioethanol Production. In press in Fuel.ഀ 13. Amigun B, D Petrie, JF Görgens. 2011. Economic risk assessment of advanced process technologies for bioethanol production in South Africa: Monte Carlo analysis. Accepted for publication in Renewable Energy.ഀ