Applied Microbiology and Biotechnology Laboratory, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.
Applied Microbiology and Biotechnology Laboratory, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.
J Biosci Bioeng. 2020 Nov;130(5):489-495. doi: 10.1016/j.jbiosc.2020.06.006. Epub 2020 Aug 1.
1-Octen-3-ol is a major aroma component of awamori, a traditional distilled liquor produced in Okinawa Prefecture, Japan. As 1-octen-3-ol is thought to affect the sensory properties of awamori, it is important to fully characterize the compound's biosynthetic pathway and control mechanism. We previously reported that the fatty acid oxygenase ppoC (ppo: psi-produced oxygenase) of Aspergillus luchuensis is directly involved in the production of 1-octen-3-ol in rice koji (Kataoka et al., J. Biosci. Bioeng., 129, 192-198, 2020). In the present study, we constructed A. luchuensis ppoD disruptants to characterize the role of ppo genes in 1-octen-3-ol biosynthesis. A small-scale awamori fermentation test was performed using ppoA, ppoC, and ppoD single disruptants (ΔppoA, ΔppoC, and ΔppoD, respectively), along with the parent strain, ΔligD. 1-Octen-3-ol was not detected in the distillate prepared using the ΔppoC strain. We conclude that A. luchuensis ppoC is the only 1-octen-3-ol-producing factor in the awamori brewing process. Because ΔppoA and ΔppoD slightly enhanced 1-octen-3-ol productivity, these two genes may play a role in negatively controlling 1-octen-3-ol biosynthesis.
1-辛烯-3-醇是日本冲绳传统蒸馏酒——泡盛酒中的一种主要香气成分。由于 1-辛烯-3-醇被认为会影响泡盛酒的感官特性，因此充分阐明其生物合成途径和调控机制非常重要。我们之前曾报道过，曲霉菌（Aspergillus luchuensis）的脂肪酸加氧酶 ppoC（ppo：psi 产生的加氧酶）直接参与了米曲（Kataoka 等人，J. Biosci. Bioeng.，129，192-198，2020）中 1-辛烯-3-醇的生成。在本研究中，我们构建了 A. luchuensis ppoD 敲除突变株，以研究 ppo 基因在 1-辛烯-3-醇生物合成中的作用。我们使用 ppoA、ppoC 和 ppoD 单敲除突变株（分别为ΔppoA、ΔppoC 和 ΔppoD）以及亲本菌株ΔligD 进行了小规模的泡盛酒发酵试验。在使用ΔppoC 菌株制备的馏出物中未检测到 1-辛烯-3-醇。我们得出结论，A. luchuensis ppoC 是泡盛酒酿造过程中唯一的 1-辛烯-3-醇产生因子。由于ΔppoA 和ΔppoD 略微提高了 1-辛烯-3-醇的产量，这两个基因可能在负调控 1-辛烯-3-醇生物合成中发挥作用。
