DEFAR - Departamento de Farmácia

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530

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2017 - 201922020 - 20221

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Autor: search.filters.author.Gurgel, Leandro Vinícius AlvesTem arquivos: Sim

Resultados da Pesquisa

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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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    Fractionation of sugarcane bagasse using hydrothermal and advanced oxidative pretreatments for bioethanol and biogas production in lignocellulose biorefineries.
    (2019) Bittencourt, Gustavo Amaro; Barreto, Elisa da Silva; Brandão, Rogélio Lopes; Baeta, Bruno Eduardo Lobo; Gurgel, Leandro Vinícius Alves
    The fractionation of sugarcane bagasse (SB) by hydrothermal pretreatment (HP, autohydrolysis) followed by alkaline extraction (AE) and advanced oxidative pretreatment (AOP) for production of second-generation ethanol and biogas was investigated. The AOP of SB was optimized using a Doehlert design, varying the applied H2O2 load, liquid-to-solid ratio (LSR), and time. The responses evaluated were yield (Y), residual cellulose (RC), delignification (DE), and enzymatic conversion (EC). The AE of SB pretreated by HP led to 61.8% DE (using 0.2 mol L−1 NaOH). This high lignin removal enabled substantial savings of H2O2 in the AOP. The optimized AOP conditions led to 78% Y, 82.2% RC, 42.7% DE, and 88.9% EC (overall glucose yield of 60.9%). Fermentation of the enzymatic hydrolysate with Saccharomyces cerevisiae yielded 190.8 Lethanol tonSB−1. Biogas production by anaerobic digestion of residual liquid streams of the pretreatment steps yielded 27.46 NLCH4 kgSB−1. An energy balance was estimated for the SB fractionation.
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    Simultaneous removal of sulfate and arsenic using immobilized nontraditional SRB mixed culture and alternative low-cost carbon sources.
    (2017) Matos, Letícia Paiva de; Costa, Patrícia Freitas; More, Mariana; Gomes, Paula Cristine Silva; Silva, Silvana de Queiroz; Gurgel, Leandro Vinícius Alves; Teixeira, Mônica Cristina
    This study was designed to obtain simultaneous sulfate (SO4 2−) and As(III) ions removal by non-traditional sulfate-reducing bacteria (SRB) growing in the presence of a protein biomass (PCF), a solid residual material produced by the poultry industry. Microbial cells and PCF were immobilized into calcium alginate beads to reduce mass losses. Microbial consortium efficiency was tested under different operational conditions: sodium lactate, glycerol and PCF as carbon sources; increasing As(III) content; acidic pH (5.0). Microbial diversity was evaluated by PCR-DGGE. Pantoea agglomerans, Enterobacter sp., Citrobacter sp., Cupriavidus metallidurans, Ralstonia sp. and Burkholderia cepacia were found. With the aim to obtain SO4 2− and As(III) simultaneous removal, three semi-continuous up-flow reactors were constructed and operated for more than 100 days to prove their feasibility and reliability. Both SO4 2− and As(III) ions were removed with 74.8% and 80% efficiency, respectively. Solid products were characterized by SEM-EDX, confirming PCF and non-traditional SRB roles during arsenic immobilization. Arsenic/sulfur compounds (possibly As/sulfides) were produced by reaction between As(III) and biogenic sulfide. Microbial consortium proved its ability of growing in an acidic environment without losing its sulfate reductive capacity by using glycerol and PCF as alternative carbon sources and tap water as micronutrients source. The non-traditional SRB culture removed both SO4 2− and As(III) ions simultaneously, with no prior step needed to guarantee As(III) oxidation to As(V). Two different mechanisms could be involved: (i) precipitation as arsenic sulfide or, (ii) adsorption onto PCF/cells calcium alginate beads.