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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Simultaneous saccharification and fermentation (SSF) of Jatropha curcas shells: utilization of co-products from the biodiesel production process(Bioprocess and Biosystems Engineering, 2011-12-04) Visser, Evan Michael; Oliveira Filho, Delly; Totola, Marcos Rogerio; Martins, Marcio Aredes; Guimaraes, Valeria MontezeJatropha curcas has great potential as an oil crop for use in biodiesel applications, and the outer shell is rich in lignocellulose that may be converted to ethanol, giving rise to the concept of a biorefinery. In this study, two dilute pretreatments of 0.5% H2SO4 and 1.0% NaOH were performed on Jatropha shells with subsequent simultaneous saccharification and fermentation (SSF) of the pretreated water-insoluble solids (WIS) to evaluate the effect of inhibitors in the pretreatment slurry. A cellulase loading of 15 FPU/g WIS, complimented with an excess of cellobiase (19.25 U/g), was used for SSF of either the washed WIS or the original slurry to determine the effect of inhibitors. Ethanol and glucose were monitored during SSF of 20 g of pretreated biomass. The unwashed slurry showed to have a positive effect on SSF efficiency for the NaOH-pretreated biomass. Maximum efficiencies of glucan conversion to ethanol in the WIS were 40.43% and 41.03% for the H2SO4- and NaOH-pretreated biomasses, respectively.Item The influence of presaccharification, fermentation temperature and yeast strain on ethanol production from sugarcane bagasse(Bioresource Technology, 2012-01-07) Souza, Carlos J.A. de; Costa, Daniela A.; Rodrigues, Marina Q.R.B.; Santos, Ancély F. dos; Lopes, Mariana R.; Abrantes, Aline B.P.; Costa, Patrícia dos Santos; Silveira, Wendel Batista; Passos, Flávia M.L.; Fietto, Luciano G.Ethanol can be produced from cellulosic biomass in a process known as simultaneous saccharification and fermentation (SSF). The presence of yeast together with the cellulolytic enzyme complex reduces the accumulation of sugars within the reactor, increasing the ethanol yield and saccharification rate. This paper reports the isolation of Saccharomyces cerevisiae LBM-1, a strain capable of growth at 42 °C. In addition, S. cerevisiae LBM-1 and Kluyveromyces marxianus UFV-3 were able to ferment sugar cane bagasse in SSF processes at 37 and 42 °C. Higher ethanol yields were observed when fermentation was initiated after presaccharification at 50 °C than at 37 or 42 °C. Furthermore, the volumetric productivity of fermentation increased with presaccharification time, from 0.43 g/L/h at 0 h to 1.79 g/L/h after 72 h of presaccharification. The results suggest that the use of thermotolerant yeasts and a presaccharification stage are key toincreasing yields in this process.Item Optimization of Endoglucanase and Xylanase activities from fusarium verticillioides for simultaneous saccharification and fermentation of sugarcane bagasse(Applied Biochemistry and Biotechnology, 2013-10-30) Almeida, Maíra N. de; Guimarães, Valéria M.; Falkoski, Daniel L.; Paes, Guilherme B. T.; Ribeiro Jr., José Ivo; Visser, Evan M.; Alfenas, Rafael F.; Pereira, Olinto L.; Rezende, Sebastião T. deEnzymatic hydrolysis is an important but expensive step in the production of ethanol from biomass. Thus, the production of efficient enzymatic cocktails is of great interest for this biotechnological application. The production of endoglucanase and xylanase activites from F. verticillioides were optimized in a factorial design (25) followed by a CCDR design. Endoglucanase and xylanase activities increased from 2.8 to 8.0 U/mL and from 13.4 to 114 U/mL, respectively. The optimal pH and temperature were determined for endoglucanase (5.6, 80 °C), cellobiase (5.6, 60 °C), FPase (6.0, 55 °C) and xylanase (7.0, 50 °C). The optimized crude extract was applied in saccharification and fermentation of sugarcane bagasse from which 9.7 g/L of ethanol was produced at an ethanol/biomass yield of 0.19.Item Direct ethanol production from glucose, xylose and sugarcane bagasse by the corn endophytic fungi Fusarium verticillioides and Acremonium zeae(Journal of Biotechnology, 2013-07-31) Almeida, Maíra N. de; Guimarães, Valéria M.; Falkoski, Daniel L.; Visser, Evan M.; Siqueira, Germano A.; Milagres, Adriane M.F.; Rezende, Sebastião T. deProduction of ethanol with two corn endophytic fungi, Fusarium verticillioides and Acremonium zeae, was studied. The yield of ethanol from glucose, xylose and a mixture of both sugars were 0.47, 0.46 and 0.50 g/g ethanol/sugar for F. verticillioides and 0.37, 0.39 and 0.48 g/g ethanol/sugar for A. zeae. Both fungi were able to co-ferment glucose and xylose. Ethanol production from 40 g/L of pre-treated sugarcane bagasse was 4.6 and 3.9 g/L for F. verticillioides and A. zeae, respectively, yielding 0.31 g/g of ethanol per consumed sugar. Both fungi studied were capable of co-fermenting glucose and xylose at high yields. Moreover, they were able to produce ethanol directly from lignocellulosic biomass, demonstrating to be suitable microorganisms for consolidated bioprocessing.Item Cellulases and hemicellulases from endophytic acremonium species and its application on sugarcane bagasse hydrolysis(Appl Biochem Biotechnol, 2011-05-02) Almeida, Maíra Nicolau de; Guimarães, Valéria Monteze; Bischoff, Kenneth M.; Falkoski, Daniel Luciano; Pereira, Olinto Liparini; Gonçalves, Dayelle S. P. O.; Rezende, Sebastião Tavares deThe aim of this work was to have cellulase activity and hemicellulase activity screenings of endophyte Acremonium species (Acremonium zeae EA0802 and Acremonium sp. EA0810). Both fungi were cultivated in submerged culture (SC) containing L -arabinose, D -xylose, oat spelt xylan, sugarcane bagasse, or corn straw as carbon source. In solid-state fermentation, it was tested as carbon source sugarcane bagasse or corn straw. The highest FPase, endoglucanase, and xylanase activities were produced by Acremonium sp. EA0810 cultivated in SC containing sugarcane bagasse as a carbon source. The highest β-glucosidase activity was produced by Acremonium sp. EA0810 cultivated in SC using D -xylose as carbon source. A. zeae EA0802 has highest α-arabinofuranosidase and α-galactosidase activities in SC using xylan as a carbon source. FPase, endoglucanase, β-glucosidase, and xylanase from Acremonium sp. EA0810 has optimum pH and temperatures of 6.0, 55 °C; 5.0, 70 °C; 4.5, 60 °C; and 6.5, 50 °C, respectively. α-Arabinofuranosidase and α-galactosidase from A. zeae EA0802 has optimum pH and temperatures of 5.0, 60 °C and 4.5, 45 °C, respectively. It was analyzed the application of Acremonium sp. EA0810 to hydrolyze sugarcane bagasse, and it was achieved 63% of conversion into reducing sugar and 42% of conversion into glucose.