Navegando por Autor "Pimentel, Vanessa Carvalho"

Agora exibindo 1 - 4 de 4

Cristalização em modo continuo assistida por ultrassom
(Universidade Federal do Rio Grande do Norte, 2016) Pimentel, Vanessa Carvalho; Macedo, Gorete Ribeiro de
O estágio foi realizado na École des Mines d’Albi Carmaux (Albi, França), mais precisamente no Centro Rapsodee, em conjunto com uma empresa francesa do ramo alimentício, durante o período de 19 de Maio de 2016 até 26 de agosto de 2016, totalizando 480 horas. O tema do estágio consistiu em Cristalização em modo continuo assistida por ultrassom. O estágio foi supervisionado pela Prof. Dra Gorete Ribeiro de Macedo, em conjunto com a Prof Dra Fabienne Espitalier (França) e Fabien Baillon (França). Durante meu tempo na França, tive a oportunidade de trabalhar com o protótipo Sonocristal e realizar diversos testes para verificar sua capacidade de ser utilizado a nível industrial.
Recovery and puriﬁcation of chitosanaseproduced by Bacillus cereus using expandedbed adsorption and central composite design
(Wiley, 2016-02) Santos, Everaldo Silvino dos; Macedo, Gorete Ribeiro de; Araújo, Nathália Kelly de; Pimentel, Vanessa Carvalho; Silva, Nayane Macedo Portela da; Padilha, Carlos Eduardo de Araújo
This study presents a system for expanded bed adsorption for the puriﬁcation of chitosanasefrom broth extract in a single step. A chitosanase-producing strain was isolated and identiﬁedas Bacillus cereus C-01 and used to produce chitosanases. The expanded bed adsorptionconditions for chitosanase puriﬁcation were optimized statistically using STREAMLINETMDEAE and a homemade column (2.6 × 30.0 cm). Dependent variables were deﬁned by thequality criteria puriﬁcation factor (P) and enzyme yield to optimize the chromatographicprocess. Statistical analyses showed that the optimum conditions for the maximum P were150 cm/h load ﬂow velocity, 6.0 cm settled bed height, and 7.36 cm distributor height.Distributor height had a strong inﬂuence on the process, considerably affecting both theP and enzyme yield. Optimizing the puriﬁcation variables resulted in an approximately3.66-fold increase in the P compared with the value under nonoptimized conditions. Thissystem is promising for the recovery of chitosanase from B. cereus C-01 and is economicallyviable because it promotes the reduction steps
Single-step purification of chitosanases from Bacillus cereus using expanded bed chromatography
(Elsevier, 2016-01) Santos, Everaldo Silvino dos; Araújo, Nathália Kelly de; Pagnoncelli, Maria Giovana Binder; Pimentel, Vanessa Carvalho; Xavier, Maria Luiza Oliveira; Padilha, Carlos Eduardo Araújo; Macedo, Gorete Ribeiro de
A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01. The purification and characterization of two chitosanases were studied. The purification assay was accomplished by ion exchange expanded-bed chromatography. Experiments were carried out in the presence and in the absence of cells through different expansion degree to evaluate the process performance. The adsorption experiments demonstrated that the biomass does not affect substantially the adsorption capacity of the matrix. The enzyme bound to the resin with the same extent using clarified and unclarified broth (0.32 and 0.30 U/g adsorbent, respectively). The fraction recovered exhibited 31% of the yield with a 1.26-fold increase on the specific activity concerned to the initial broth. Two chitosanases from different elution steps were recovery. Chit A and Chit B were stable at 30–60 ◦C, pH 5.5–8.0 and 5.5–7.5, respectively. The highest activity was found at 55 ◦C, pH 5.5 to Chit A and 50 ◦C, pH 6.5 to Chit B. The ions Cu2+, Fe2+ and Zn2+ indicated inhibitory effect on chitosanases activities that were significantly activated by Mn2+. The methodology applied in this study enables the partial purification of a stable chitosanase using a feedstock without any pre-treatment using a single-step purification
Utilization of agroindustrial residues for producing cellulases by Aspergillus fumigatus on Semi-Solid Fermentation
(Elsevier, 2018-02) Santos, Everaldo Silvino dos; Oliveira, Sérgio Dantas; Padilha, Carlos Eduardo de Araújo; Asevedo, Estefani Alves; Pimentel, Vanessa Carvalho; Araújo, Fernanda Rodrigues de; Macedo, Gorete Ribeiro de
Agroindustrial biomasses (sugarcane bagasse, green coconut husk and cashew apple bagasse) are used as substrate for producing cellulases by Aspergillus fumigatus on Semi-Solid Fermentation (SSF). The untreated lignocellulosics and fermented sugarcane bagasse are characterized using the National Renewable Energy Laboratory (NREL) protocols analysis as well as through Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) assays. A two-variable central composite rotatable design (CCRD) coupled to response surface methodology (RSM) with three experiments at center point are used to investigate the influence of initial moisture and pH on carboxymethycellulose and filter paper, i.e., CMCase and FPase activities produced by the Aspergillus fumigatus using all of the three lignocellulosic biomasses. Results show that sugarcane bagasse has the highest cellulose content and the cashew apple bagasse the highest lignin content, approximately 46.0%. Additionally, pH and moisture (linear and quadratic parameters), as well as their combination, play a key role on both CMCase and FPase activities. The highest values for CMCase and FPase are 4.20 U/g and 0.64 U/g for sugarcane bagasse; 4.07 U/g and 0.28 U/g for coconut husk and 0.64 U/g and 0.32 U/g for cashew apple bagasse. The use of SSF for producing cellulases can be an option for reducing energy consumption due to reduction on the steps during biomass pretreatment

SIGAA

Navegando por Autor "Pimentel, Vanessa Carvalho"