After several decades during which proteases and after lipases took the biotransformation world scene as the predominant biocatalysts, a new, promising enzyme was discovered and characterized. The acyltransferase from Mycobacterium smegmatis (MsAcT) has in fact an extraordinary activity for a wide array of reactions,

such as trans-esterification, amidation, trans-amidation and perhydrolysis, both in water and solvent media, giving rise to a series of interesting compounds including APIs (i.e., active pharmaceutical ingredients), natural flavors and fragrances, monomers for polymer synthesis, and peracids employed as disinfectants or antimicrobials. Although the most used acylating agent has been ethyl acetate (EtOAc), depending on the reaction type also acetamide, dimethyl carbonate and a variety of other esters, have been reported. The best yields were reached using very reactive donors such as vinyl or isopropenyl esters (almost complete conversion in rapid reaction times and water media for condensation reactions). In this review article the most innovative scientific advances on MsAcT, its mechanism and engineering are summarized, putting a particular focus on the different kind of processes (batch and flow) that it is possible to carry out using this enzyme as free or immobilized form. In conclusion, the author personal view on the unexplored reaction possibilities using MsAcT is reported as a window on the future of the topic.

在蛋白酶和脂肪酶以生物转化领域为主要生物催化剂的几十年后，发现并表征了一种新的、有前途的酶。耻垢分枝杆菌(MsAcT)的酰基转移酶实际上对广泛的反应具有非凡的活性，

例如在水和溶剂介质中的酯交换、酰胺化、酰胺交换和过水解，产生了一系列有趣的化合物，包括 API（即活性药物成分）、天然香料和香料、用于聚合物合成的单体以及用作消毒剂或抗微生物剂的过酸。尽管最常用的酰化剂是乙酸乙酯 (EtOAc)，但根据反应类型的不同，也有乙酰胺、碳酸二甲酯和各种其他酯类的报道。使用非常活泼的供体如乙烯基或异丙烯酯（在快速反应时间和缩合反应的水介质中几乎完全转化）可以达到最佳产率。在这篇评论文章中，对 MsAcT 的最具创新性的科学进展、其机制和工程进行了总结，特别关注使用这种酶作为游离或固定形式可能进行的不同类型的过程（分批和流动）。综上所述，