Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, 159 Long Pan Road, Nanjing 210037, China; College of Chemical Engineering, Nanjing Forestry University, 159 Long Pan Road, Nanjing 210037, China.
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, 159 Long Pan Road, Nanjing 210037, China.
Int J Biol Macromol. 2024 Oct;277(Pt 4):134538. doi: 10.1016/j.ijbiomac.2024.134538. Epub 2024 Aug 5.
Dihydro-β-ionone, a high-value compound with distinctive fragrance, is widely utilized in the flavor and fragrance industries. However, its low abundance in plant sources poses a significant challenge to its application through traditional extraction methods. Development of an enzyme cascade reaction with artificial design offers a promising alternative. Herein, a short-chain dehydrogenase NaSDR, was identified from Novosphingobium aromaticivorans DSM 12444, which exhibited a high activity in converting β-ionol to β-ionone. A novel biosynthesis route to produce dihydro-β-ionone from β-ionol was developed, by utilizing alcohol dehydrogenase NaSDR and enoate reductase AaDBR1. Under the optimized conditions (0.29 mg/mL NaSDR, 0.39 mg/mL AaDBR1, 1 mM NADP and 2.5 mM β-ionol at 40 °C for 2 h), a maximum yield (173.11 mg/L) of dihydro-β-ionone was achieved with a molar conversion rate of 35.6 %, which was 2.7-fold higher than that before optimization. Additionally, this cascade reaction achieved self-sufficient NADPH regeneration through the actions of NaSDR and AaDBR1. This study offered a fresh perspective for achieving a green and sustainable synthesis of dihydro-β-ionone and could inspire on another natural products biosynthesis.
二氢-β-紫罗兰酮是一种具有独特香气的高价值化合物，广泛应用于香精和香料行业。然而，其在植物源中的含量较低，通过传统提取方法应用具有很大的挑战性。通过人工设计的酶级联反应开发提供了一种有前途的替代方法。本文从 Novosphingobium aromaticivorans DSM 12444 中鉴定出一种短链脱氢酶 NaSDR，该酶在将β-紫罗兰酮转化为β-紫罗兰酮方面表现出很高的活性。利用醇脱氢酶 NaSDR 和烯酸还原酶 AaDBR1，开发了一种从β-紫罗兰酮生产二氢-β-紫罗兰酮的新型生物合成途径。在优化条件下（0.29 mg/mL NaSDR、0.39 mg/mL AaDBR1、1 mM NADP 和 2.5 mM β-紫罗兰酮，40°C 反应 2 h），二氢-β-紫罗兰酮的最大产量（173.11 mg/L）达到，摩尔转化率为 35.6%，比优化前提高了 2.7 倍。此外，该级联反应通过 NaSDR 和 AaDBR1 的作用实现了 NADPH 的自给自足再生。本研究为实现二氢-β-紫罗兰酮的绿色可持续合成提供了新的视角，并可能为其他天然产物的生物合成提供启示。
