C.N.R. Istituto di Chimica del Riconoscimento Molecolare, Milan, Italy.
J Appl Microbiol. 2018 Mar;124(3):719-729. doi: 10.1111/jam.13680. Epub 2018 Feb 2.
The preparation of the high-value flavour γ-dodecalactone is based on the biotransformation of natural 10-HSA, which is in turn obtained by microbial hydration of oleic acid. We want to establish a reliable baker's yeast-mediated procedure for 10-HSA preparation.
The previously reported yeast-mediated hydration procedures are unreliable because bacteria-free baker's yeast is not able to hydrate oleic acid. The actual responsible for performing this reaction are the bacterial contaminants present in baker's yeast. Moreover, we demonstrated that the enantioselectivity in the production of (R)-10-HSA is affected mainly by the temperature used in the biotransformation.
We demonstrated that Saccharomyces cerevisiae is not able to hydrate oleic acid, whereas different bacterial strains present in baker's yeast transform oleic acid into (R)-10-HSA. We reported a general procedure for the preparation of (R)-10-HSA starting from oleic acid and using commercially available baker's yeast.
This study holds both scientific and industrial interest. It unambiguously establishes that the eukaryote micro-organisms present in baker's yeast are not able to hydrate oleic acid. The isolation of oleic acid hydrating bacterial strains from commercial baker's yeast points to their prospective use for the industrial synthesis of 10-HSA.
高附加值风味γ-十二内酯的制备基于天然 10-HSA 的生物转化，而 10-HSA 则是通过油酸的微生物水合作用获得的。我们希望建立一种可靠的面包酵母介导的 10-HSA 制备方法。
先前报道的酵母介导的水合作用程序不可靠，因为无细菌的面包酵母不能水合油酸。实际上负责进行此反应的是存在于面包酵母中的细菌污染物。此外，我们证明了在（R）-10-HSA 的生产中，对映选择性主要受生物转化中使用的温度影响。
我们证明了酿酒酵母不能水合油酸，而面包酵母中存在的不同细菌菌株将油酸转化为（R）-10-HSA。我们报告了一种从油酸开始，使用市售面包酵母制备（R）-10-HSA 的一般方法。
这项研究具有科学和工业意义。它明确表明，面包酵母中的真核微生物不能水合油酸。从商业面包酵母中分离出的油酸水合细菌菌株表明它们有望用于 10-HSA 的工业合成。
