Browsing by Author "Baffi, Milla Alves"

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    Avaliação do pré-tratamento hidrotérmico da casca de café na hidrólise enzimática e produção de biogás.
    (2019) Silva, Nayara Clarisse Soares; Baeta, Bruno Eduardo Lobo; Gurgel, Leandro Vinícius Alves; Baeta, Bruno Eduardo Lobo; Gurgel, Leandro Vinícius Alves; Baffi, Milla Alves; Aquino, Sergio Francisco de
    Sabe-se que a biomassa lignocelulósica pode ser utilizada na produção de biocombustíveis como bioetanol e biogás. O Brasil destaca-se mundialmente por sua produção de café, sendo que, durante o beneficiamento dos grãos de café são geradas grandes quantidades de resíduos, como a casca. Entretanto, para um melhor aproveitamento energético desta biomassa lignocelulósica é importante adicionar uma etapa de pré-tratamento para tornar os açúcares fermentescíveis mais disponíveis, destacando-se o pré tratamento hidrotérmico.. Portanto, o objetivo deste trabalho foi avaliar o pré-tratamento hidrotérmico da casca de café, utilizando o planejamento experimental Box-Behnken, a melhor estratégia de utilização da casca de café como matéria prima para uma biorrefinaria lignocelulósica. Foram avaliadas 15 condições experimentais utilizando as variáveis independentes: temperatura (120 a 200°C), tempo (20 a 90 minutos) e razão líquido/sólido (5 a 10 mLg-1). Observou-se que nas condições com temperatura igual a 200 °C se obteve alta remoção de celulose, o que prejudicou o rendimento global do processo em relação à glicose recuperada visando a produção de etanol de segunda geração. Para obter um melhor rendimento no processo na hidrólise enzimática, foi gerada uma condição de desejabilidade visando a produção de etanol. Visando avaliar outras rotas de aproveitamento da biomassa, foram avaliadas a digestão anaeróbia (DA) de três condições de desejabilidade – CDB1 (120 °C, 20 min e 5 mL g-1), CDB2 (189 °C, 90 min e 5 mL g-1), CDB3 (200 °C, 61 min e 5 mL g-1). Além destas condições, realizou-se a DA do hidrolisado gerado na CDE. De maneira geral o pré-tratamento foi eficiente para aumentar a digestibilidade da biomassa. Além disso, vale ressaltar que a elevada concentração de compostos fenólicos interferiu negativamente na produção de metano, inibindo a produção na DA em estado sólido e semissólido da CDB3. A maior produção de metano em relação a DQO de entrada foi para a CDB3 em estado líquido. Por outro lado, a alta demanda energética do pré-tratamento não foi possível recuperar o gasto energético nesta condição. Desta forma, a condição que apresentou melhor rentabilidade econômica (R$ 150,00 ton de casca bruta-1) foi a CDE, utilizando a fração sólida para hidrolise enzimática visando a produção de etanol e o hidrolisado para produção de metano, adicionando ao sistema a combustão de 0,125 toneladas de casca bruta para suprir o déficit energético para pré tratar 1 tonelada de cascas destas condições.
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    Biomass sorghum as a novel substrate in solid-state fermentation for the production of hemicellulases and cellulases by Aspergillus niger and A. fumigatus.
    (2017) Dias, Lídia Manfrin; Santos, Beatriz Vieira dos; Albuquerque, Carlos Juliano Brant; Baeta, Bruno Eduardo Lobo; Pasquini, Daniel; Baffi, Milla Alves
    Aims: We investigated the role of carbon and nitrogen sources in the production of cellulase and hemicellulase by Aspergillus strains. Methods and Results: The strains Aspergillus niger SCBM1 and Aspergillus fumigatus SCBM6 were cultivated under solid-state fermentation (SSF), with biomass sorghum (BS) and wheat bran (WB) as lignocellulosic substrates, in different proportions, along with variable nitrogen sources. The best SSF condition for the induction of such enzymes was observed employing A. niger SCBM1 in BS supplemented with peptone; maximum production levels were achieved as follows: 72 h of fermentation for xylanase and exoglucanase (300 07 and 30 64 U g 1 respectively), 120 h for b-glucosidase and endoglucanase (54 90 and 41 47 U g 1 respectively) and 144 h for b-xylosidase (64 88 U g 1). Conclusions: This work demonstrated the viability of the use of BS for the production of hemi- and cellulolytic enzymes; the high concentration of celluloses in BS could be associated with the significant production of cellulases, mainly exoglucanase. Significance and Impact of the Study: This is the first study which presents the promising use of biomass sorghum (genetically modified sorghum to increase its biomass content) as an alternative carbon source for the production of enzymes by SSF.
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    Biomass sorghum as a novel substrate in solid-state fermentation for the production of hemicellulases and cellulases by Aspergillus niger and A. fumigatus.
    (2018) Dias, Lídia Manfrin; Santos, Beatriz Vieira dos; Albuquerque, Carlos Juliano Brant; Baeta, Bruno Eduardo Lobo; Pasquini, Daniel; Baffi, Milla Alves
    We investigated the role of carbon and nitrogen sources in the production of cellulase and hemicellulase by Aspergillus strains.
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    Lignocellulose-degrading enzymes production by solid-state fermentation through fungal consortium among Ascomycetes and Basidiomycetes.
    (2020) Rodrigues, Patrísia de Oliveira; Gurgel, Leandro Vinícius Alves; Pasquini, Daniel; Badotti, Fernanda; Góes Neto, Aristóteles; Baffi, Milla Alves
    In this study, five fungal strains (Aspergillus niger SCBM1 – Ni, Aspergillus fumigatus SCBM6 – Fu, Trametes versicolor 561 – Tr, Ganoderma lucidum 601 – Ga and Pleurotus ostreatus PL06 – Pl) were cultivated individually and in consortium for biosynthesis of lignocellulose-degrading enzymes by solid-state fermentation (SSF). The enzyme production was investigated using a 25−1 fractional factorial design, with a total of 16 experiments (F1–F16) using raw sugarcane bagasse and raw wheat bran as substrates. Among the enzymatic extracts produced, Ni (F1) exhibited the highest production of endoglucanase (82.70 U/gds) (units per gram of dry substrate), exoglucanase (80.48 U/gds), β-xylosidase (145.01 U/gds) and manganese peroxidase (3.38 U/gds). For filter paper cellulase, Tr cocktail (F5) was the one that stood out (9.45 U/gds). Among the extracts produced in consortium, Ni + Tr + Pl (F6) presented the highest production of β-glucosidase (171.09 U/gds), β-xylosidase (139.99 U/gds) and manganese peroxidase (3.29 U/gds). For FPase, Ni + Fu + Ga (F12) exhibited the best production (10.46 U/gds). The highest xylanase biosynthesis (2582.38 U/gds) was obtained in Ni + Fu + Pl extract (F4). For laccase, the maximum biosynthesis (25.27 U/gds) was obtained in Tr + Ga + Pl (F13). The cocktails that presented the best enzyme production were: Ni (F1), Ni + Fu + Pl (F9), Ni + Tr + Pl (F6) and Ni + Ga + Pl (F10), demonstrating that the use of microbial consortium can be a promising alternative to obtain enzymatic cocktails with high synergism.
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    On‐site produced enzyme cocktails for saccharifcation and ethanol production from sugarcane bagasse fractionated by hydrothermal and alkaline pretreatments.
    (2022) Rodrigues, Patrísia de Oliveira; Barreto, Elisa da Silva; Brandão, Rogélio Lopes; Gurgel, Leandro Vinícius Alves; Pasquini, Daniel; Baffi, Milla Alves
    Enzymatic blends produced by fungal monocultures and consortia cultured in solid-state fermentation (SSF), using sugarcane bagasse (SB) and wheat bran as substrates (1:1, w/w), were evaluated for saccharifcation of sugarcane bagasse pretreated by autohydrolysis (hydrothermal pretreatment—HP) and alkaline delignifcation (HP-Soda). The highest glucose releases were obtained after saccharifcations of SB pretreated by HP using enzyme cocktails produced by Aspergillus niger and by the consortium among A. fumigatus, Ganoderma lucidum and Trametes versicolor, with 10.8 and 9.8 g L−1, respectively. For SB pretreated by HP-Soda, the hydrolysate 10 (extract from A. niger, G. lucidum and Pleurotus ostreatus consortium) achieved maximal glucose concentration (11.92 g L−1). After alcoholic fermentation of the hydrolysates, the greatest ethanol yield in relation to the maximum theoretical yield (60.8%) was obtained in the fermentation of hydrolysate 1 (A. niger) obtained from SB pretreated by HP-Soda. These results demonstrated that on-site produced enzyme cocktails can be applied for sac- charifcation of pretreated sugarcane bagasse and also contribute to cost reduction of bioconversion processes.
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    Pretreated sugarcane bagasse with citric acid applied in enzymatic hydrolysis.
    (2020) Gomes, Michelle Garcia; Santos, Renata Vidal dos; Barreto, Elisa da Silva; Baffi, Milla Alves; Gurgel, Leandro Vinícius Alves; Baeta, Bruno Eduardo Lobo; Pasquini, Daniel
    The objective of the study was to evaluate the pretreatment of sugarcane bagasse (SCB) with diluted citric acid solution in a pressurized system and its behavior when submitted to enzymatic hydrolysis using the Cellic CTec 3 enzyme complex, employing a Doehlert’s experimental design (23 ), with 5 central points (CP). The operating variables were temperature (T, °C), time (t, min) and percentage by weight of citric acid in relation to bagasse (PCA, wt%), ranging from 120 to 180°C for 20 to 90 min and 3 to 12 wt%, respectively. The pretreatments were effective in promoting changes in compositions of lignin, hemicellulose, and cellulose in all samples in relation to raw SCB. The concentrations of the glucose reached the maximum, 23.74 g/L, for the pretreated sample with temperature of 160°C, PCA 5.25 wt%, and reaction time of 20 min, while the xylose reached the maximum, 5.23 g/L, with the sample ob tained in the temperature of 150 C, PCA 7.5 wt% and 55 min.
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    Pretreatment of sugarcane bagasse using citric acid and its use in enzymatic hydrolysis.
    (2020) Gomes, Michelle Garcia; Gurgel, Leandro Vinícius Alves; Baffi, Milla Alves; Pasquini, Daniel
    This study evaluated the use of a renewable organic acid (citric acid) as homogeneous catalyst for the pretreatment of raw sugarcane bagasse (SB). A 22 central composite design with two factors (reaction time and citric acid concentration) was used to evaluate the effect of the factors on the chemical composition of the pretreated SB samples and enzymatic hydrolysis efficiency. The enzymatic hydrolysis experiments of the pretreated SB samples were performed using the enzymatic cocktail Cellic® CTec 3 and the total reducing sugars (TRS) released after enzymatic hydrolysis was determined. In addition, scanning electron microscopy and X-ray diffraction were used to examine the changes in the morphology and structure of the pretreated SB samples. The changes in the structure and chemical composition of the pretreated SB resulted in a high TRS concentration (28.2 g L 1 ) after enzymatic hydrolysis, for the pre treatment condition employing 6 wt% citric acid and 102.4 min, compared to the raw SB (3.06 g L 1 ). The pretreatment showed potential for application since a moderate conversion of polysaccharides in TRS was obtained, even though it was a pretreatment carried out under milder conditions. The pretreatment studied has the advantage of using weak and environmentally friendly acid catalyst, atmospheric pressure, and low temperature.
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    Pretreatment of sugarcane bagasse with dilute citric acid and enzymatic hydrolysis : use of black liquor and solid fraction for biogas production.
    (2022) Gomes, Michelle Garcia; Paranhos, Aline Gomes de Oliveira; Camargos, Adonai Bruneli de; Baeta, Bruno Eduardo Lobo; Baffi, Milla Alves; Gurgel, Leandro Vinícius Alves; Pasquini, Daniel
    This study evaluated the pretreatment of sugarcane bagasse (SCB) with dilute citric acid solution for biogas production. The black liquor (BL) from pretreatment and residual solid fraction (RSF) obtained after enzymatic hydrolysis were used as substrates for the biogas production. After saccharifications of the pretreated solid fractions performed with Cellic® CTec 3 cocktail, the highest concentration of total reducing sugars (TRS) was in the range of 10.7–184.8 g L−1 and the sugar yields were in the range of 3.5–88.8%. For BL, the contents of glucose, xylose, and arabinose were in the range of 1.9–8.9 g L−1, 4.0–24.7 g L−1, and 0.2–5.4 g L−1, respectively. Biogas production from BL and RSF resulted, respectively, in maximum values of 563.6 and 57.8 NmL gCOD−1, indicating the feasibility of using dilute citric acid pretreatment coupled to biogas production in biorefineries. Brief energy and economic assessment were carried out considering the energy balance (thermal energy generated by burning biogas - thermal energy spent in the pretreatment), as well as revenue from a possible sale of electricity generated in a combined heat and power system.