Institute of Chemical and Environmental Engineering, Slovak University of Technology Radlinského 9, Bratislava 812 37, Slovakia; Axxence Slovakia s.r.o, Mickiewiczova 9, Bratislava 811 07, Slovakia.
Austrian Center of Industrial Biotechnology, Krenngasse 37, Graz 8010, Austria; Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, Graz 8010, Austria.
J Biotechnol. 2024 Sep 20;393:161-169. doi: 10.1016/j.jbiotec.2024.08.004. Epub 2024 Aug 8.
2-Hydroxy-3-pentanone and 3-hydroxy-2-pentanone are flavor molecules present in various foods, such as cheese, wine, durian, and honey, where they impart buttery, hay-like, and caramel-sweet aromas. However, their utilization as flavoring agents is constrained by a lack of developed synthesis methods. In this study, we present their synthesis from simple starting compounds available in natural quality, catalyzed by previously characterized ThDP-dependent carboligases. Additionally, we demonstrate that newly discovered homologues of pyruvate dehydrogenase from E. coli (EcPDH E1), namely LaPDH from Leclercia adecarboxylata, CnPDH from Cupriavidus necator, and TcPDH from Tanacetum cinerariifolium, exhibit promising potential for α-hydroxy pentanone synthesis in form of whole-cell biocatalysts. Enzyme stability at varying pH levels, kinetic parameters, and reaction intensification were investigated. CnPDH, for example, exhibits superior stability across different pH levels compared to EcPDH E1. Both α-hydroxy pentanones can be produced with CnPDH in satisfactory yields (74% and 59%, respectively).
2-羟基-3-戊酮和 3-羟基-2-戊酮是存在于各种食品中的风味分子，如奶酪、葡萄酒、榴莲和蜂蜜，它们赋予了奶油味、干草味和焦糖甜味的香气。然而，由于缺乏成熟的合成方法，它们的应用作为调味剂受到了限制。在这项研究中，我们使用先前经过表征的 ThDP 依赖性碳链裂解酶，从天然质量中可用的简单起始化合物合成了它们。此外，我们还证明了来自大肠杆菌（EcPDH E1）的新发现的丙酮酸脱氢酶同源物，即来自 Leclercia adecarboxylata 的 LaPDH、来自 Cupriavidus necator 的 CnPDH 和来自 Tanacetum cinerariifolium 的 TcPDH，在全细胞生物催化剂形式下具有α-羟基戊酮合成的潜在应用价值。我们研究了酶在不同 pH 值下的稳定性、动力学参数和反应强化。例如，与 EcPDH E1 相比，CnPDH 在不同 pH 值下表现出更好的稳定性。使用 CnPDH 可以以令人满意的产率（分别为 74%和 59%）生产这两种α-羟基戊酮。
