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 minutes 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，大多数对木聚糖酶的研究已将桦木木聚糖用作活性测定的标准底物。但是，最近，主要供应商停止了Birchwood木聚糖的生产，从而产生了对替代品的重要需求。为了进行结果比较，正在进行的和将来的研究需要具有与停产的木聚糖相当的特性的底物。在这种情况下，报道了用于生产类似于已停产的商业桦木木聚糖的底物的方案。从漂白的桉树纤维素纸浆中获得木聚糖，在25°C下用4％w / v NaOH溶液萃取木聚糖，用冰醋酸（HOAc）沉淀，然后冷冻干燥。在高压釜中进行15分钟的热处理可以增加其溶解度。所得木聚糖通过红外光谱表征，热重分析和NMR。当评估木聚糖酶的活性时，结果与商业化的桦木木聚糖的结果相同。