Graduate Program in Chemical Engineering, Federal University of São Carlos, PO Box 676, São Carlos, São Paulo, Brazil.
Graduate Program in Chemical Engineering, Federal University of São Carlos, PO Box 676, São Carlos, São Paulo, Brazil; Chemical Engineering Department, Federal University of São Carlos, PO Box 676, São Carlos, São Paulo, Brazil.
Carbohydr Polym. 2018 Oct 1;197:167-173. doi: 10.1016/j.carbpol.2018.05.088. Epub 2018 May 31.
Over the past decades, most studies with xylanases have used Birchwood xylan as the standard substrate for activity assays. However, recently, Birchwood xylan production was discontinued by major suppliers, creating an important demand for a substitute. Ongoing and future studies require a substrate with characteristics equivalent to the discontinued xylan, in order to enable the comparison of results. In this context, a protocol for the production of a substrate similar to the discontinued commercial Birchwood xylan is reported. Obtained from bleached Eucalyptus cellulose pulp, xylan was extracted using 4% w/v NaOH solution at 25 °C, precipitated with glacial acetic acid (HOAc), and freeze-dried. A thermal pretreatment in an autoclave for 15 min increased its solubility. The resulting xylan was characterized by infrared spectroscopy, thermogravimetry, and NMR. When assessing the activity of xylanases, the results were the same as those for commercial Birchwood xylan.
在过去的几十年中，大多数使用木聚糖酶的研究都将桦木木聚糖用作活性测定的标准底物。然而，最近，主要供应商停止了桦木木聚糖的生产，这就产生了对替代品的重要需求。正在进行和未来的研究需要一种具有与已停产木聚糖等效特性的底物，以便能够比较结果。在这种情况下，报道了一种类似于已停产商业桦木木聚糖的底物的生产方案。该木聚糖从漂白的桉树纤维素纸浆中获得，使用 4% w/v 的 NaOH 溶液在 25°C 下提取，用冰醋酸（HOAc）沉淀，然后冻干。在高压釜中进行 15 分钟的热预处理可以提高其溶解度。通过红外光谱、热重分析和 NMR 对得到的木聚糖进行了表征。在评估木聚糖酶的活性时，结果与商业桦木木聚糖相同。
