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  • The monomer composition and the variation in the cryogelatio


    The monomer composition and the variation in the cryogelation process can result in cryogels with slightly different properties. The adequate characterization of these matrices is advisable in the studies aiming a better understanding of flow inside its structure and also the interactions between the functional groups of the matrix and the target molecules [27]. The characterization includes the determination of physical, hydrodynamical, chemical and thermal properties, which allows predicting the behavior of the chromatographic material during its storage and under operational conditions [24,27]. These adsorbents are usually chemically modified by the incorporation of functional groups on its surface, in order to increase their adsorptive capacity and/or their selectivity towards a fluvastatin mg of interest. Thus, cryogels can be used in capture or purification of molecules by exploiting various types of interactions, such as affinity [24,28] ion exchange [25,27,29] and hydrophobic interaction [30], among others, just by the chemical binding of a suitable ligand. Thus, this work reports the preparation of a polyacrylamide cryogel grafted with 2-(dimethylamino)ethyl methacrylate (DMAEMA), aiming to investigate the capture of β-glucosidase produced by solid fermentation of the fungus Thermoascus aurantiacus. The effect of the stirring time on the β-glucosidase extraction was assessed. The adsorbent was also characterized in terms of its morphological and hydrodynamic properties and then the adsorption study was conducted.
    Materials and methods
    Results and discussion
    Conclusion This study deals with the capture of β-glucosidase from thermophilic fungi Thermoascus aurantiacus.The ion-exchange cryogel showed desirable properties such as high porosity, low dispersion, low flow resistance and high stability. Adsorption of the β-glucosidase as a function of the pH was tested using a chromatographic system. Taking into account the isoelectric point of the enzyme and the point of zero charge of the adsorbent, pH 5.0 presented higher recovery of the enzymatic activity. However, higher specific activity was obtained at pH 7.0 and the eluate at this pH presented only one dense band on the electrophoresis gel. The purification factor was low probably due to isocratic elution and so other proteins were not separated from the β-glucosidase by ionic strength. This suggests that gradient elution could be studied in the future. An increase in the number of purification steps implies a greater protein loss and greatly increases the cost of the process, which makes the industrial plants try to use as few downstream processes as possible. In this study, no previous stages of clarification have been carried out. The enzyme extract flowed through the adsorbent without any obstruction from the pores, so this adsorbent is an attractive support for the separation of biomolecules, reducing both time and costs.
    Acknowledgements The authors thank the São Paulo Research Foundation - FAPESP (Grant number 2016/17812-6 and 2017/16482-5) for their financial support. The authors would like to thank the Centre of Analysis and Chemical Prospecting of the Federal University of Lavras, Electron Microscopy Lab of the Federal University of Lavras, Minas Gerais State Agency for Research and Development - FAPEMIG (Grants No. TEC - APQ-00647-17), National Council for Scientific and Technological Development - CNPq (Grant number 426578/2016-3) and Coordination for the Improvement of Higher Education Personnel - CAPES for supplying the equipment and technical support for experiments involving FTIR, DSC and TGA analyses.
    Introduction Diabetes occurs when the pancreas is unable to produce insulin or when the body is unable to properly use the insulin it does produce. The International Diabetes Federation reports that globally around 425 million adults are currently affected by diabetes, with this number predicted to increase to around 700 million people by 2045 [1]. Type 2 diabetes is the most prevalent cause of diabetes, which is largely preventable through changes in diet and lifestyle. This form of diabetes is linked to excess intake of foods rich in rapidly digestible carbohydrates, such as starch and its derivatives [2,3]. Starches are broken down into sugars in the human body by digestive enzymes, such as α-glucosidase [4]. The rapid release of glucose within the gastrointestinal tract (GIT) leads to a spike in blood glucose levels, thereby increasing the risk of diabetes [5]. Inhibition of α-glucosidase may therefore be an effective strategy for hindering starch digestion and glucose absorption within the human body.