Abstract

The biocatalyzed synthesis of purine nucleosides and their analogs is a case widely studied due to the high pharmaceutical interest of these compounds, providing the whole-cell biocatalysts, a useful tool for this purpose. Vidarabine and fludarabine are commercial examples of expensive bioactive nucleosides that can be prepared using a microbial transglycosylation approach. Citrobacter koseri whole-cells immobilized on agarose beads proved to be an interesting option to transform this biotransformation in a preparative process. The entrapment matrix provided a useful and resistant multipurpose biocatalyst regarding its stability, mechanical strength, microbial viability and reuse. Immobilized biocatalyst retained the initial activity for up to 1 year storage and after 10 years, the biocatalyst did not show cell leaking and still exhibited residual activity. In addition, the biocatalyst could be reused in batch 68 times keeping up to 50% of the initial biocatalytic activity and for at least 124 h in a continuous process.

中文翻译：

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固定在琼脂糖珠上用于核苷合成的科氏柠檬酸杆菌：用于制备用途的潜在生物催化剂

摘要

嘌呤核苷及其类似物的生物催化合成已被广泛研究，因为这些化合物具有很高的药用价值，可提供全细胞生物催化剂，这是一种有用的工具。维达拉滨和氟达拉滨是可以使用微生物转糖基化方法制备的昂贵生物活性核苷的商业实例。科氏柠檬酸杆菌固定在琼脂糖珠上的全细胞被证明是在制备过程中转化这种生物转化的有趣选择。截留基质在其稳定性，机械强度，微生物生存力和再利用方面提供了一种有用且具有抵抗力的多功能生物催化剂。固定化的生物催化剂可以保留长达一年的初始活性，并且在10年后，该生物催化剂没有显示出细胞渗漏，仍然表现出残留的活性。此外，该生物催化剂可分批重复使用68次，最多可保持初始生物催化活性的50％，并且在连续过程中至少可使用124小时。