Prebiotic galacto-oligosaccharides (GOSs) are synthesized by transgalactosylation of lactose using β-galactosidases. Well-established, large-scale production of GOS is performed by stirred-tank reactors (STR) operating in batch fashion. Main manufacturing expenses are attributed to enzyme purchase costs and the downstream operations required for subsequent enzyme inactivation and removal. In the last decades, several studies and patents have appeared on free enzyme membrane reactor (FEMR) as an economic alternative to STR due to enhanced enzyme recovery and reuse. In this review, we attempt to summarize the key design aspects, the catalytic performance and efficiency of FEMR compared to STR technology, and the main concerns related to stable product quality over long-term operation.

中文翻译：

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利用游离 β-半乳糖苷酶通过酶膜反应器生产低聚半乳糖 

益生元低聚半乳糖 (GOS) 通过使用β-半乳糖苷酶对乳糖进行转半乳糖基化来合成。GOS 的成熟大规模生产是通过以间歇方式运行的搅拌釜反应器 (STR) 进行的。主要制造费用归因于酶购买成本以及后续酶失活和去除所需的下游操作。在过去的几十年中，由于增强了酶的回收和再利用，出现了一些关于游离酶膜反应器 (FEMR) 的研究和专利，作为 STR 的经济替代品。在这篇综述中，我们试图总结 FEMR 与 STR 技术相比的关键设计方面、催化性能和效率，以及与长期运行中稳定的产品质量相关的主要问题。