Navegando por Autor "Xavier, Maria Luiza Oliveira"
Agora exibindo 1 - 2 de 2
- Resultados por página
- Opções de Ordenação
Artigo Ion exchange expanded bed chromatography for the purification of an extracelular chitosanase from Bacillus cereus(BMC Proceedings, 2014-10-01) Santos, Everaldo Silvino dos; Xavier, Maria Luiza Oliveira; Araújo, Nathália Kelly de; Macedo, Gorete Ribeiro deOligosaccharides have gained considerable interest in the pharmaceutical chemical, food and medical area, due to their biological properties such as the antibacterial [1], antifungal [2], prebiotic, antidiabetic, immunostimulating and antimutagenic activity, acceleration of calcium absorption, recovery of tissue stimulation and activation of plant resistance against insects and pathogen attacks [3], and antitumor functions [4], and thus have been used in agriculture, food and pharmaceutical industries [5]. The enzyme chitosanase is commonly used in the hydrolysis of chitosan. In this work, the ion exchange Streamline DEAE resin was used on an expanded bed system for chitosanase studies purification. In the first step the adsorption characteristic was determined, followed by the comparison between expansion degree using crude unclarified broth and cell-freeArtigo 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 deA 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