2-苯乙醇生物合成的研究进展

Research progress in 2-phenylethanol production through biological processes

2-苯乙醇(2-PE)是一种具有玫瑰香味的重要香料化合物,广泛应用于化妆品、香水、食品等行业。传统的2-PE生产主要是从植物原料中提取或化学合成。然而,这些方法无法满足消费者对天然香料日益增长的需求。以发酵法或酶法生产的L-苯丙氨酸为前体,利用酵母细胞将其转化为2-PE,产品既符合环境友好的要求,又满足“天然”产品的定义,可以取代从玫瑰或其他植物精油中提取的天然2-PE。因此,生物法合成2-PE已经引起人们的广泛关注。本文综述了生物法合成2-PE的现状和发展前景,指出相对于传统的化学合成和天然植物提取,生物转化比较具有优越性。并对2-PE的合成途径、全局调控机制、提高2-PE产量的策略以及农工废弃物作为原料的利用进行了系统的论述。此外,本文还讨论了原位产物分离技术在2-PE生物合成中的应用。

2-Phenylethanol(2-PE),an important flavor and fragrance compound with a rose-like smell has been widely used in the cosmetics,perfume,and food industries.Furthermore,it is also an important raw material for the derivatives synthesis for the synthesis of other flavors or pharmaceutical compounds,such as 2-phenylethylacetate(2-PEAc)and phenylacetaldehyde(PA).Conventional production of 2-PE is mainly through the extraction from plant materials,such as hyacinths,jasmine and lilies.However,the extraction process is very complicated and the harvest of flowers is greatly influenced by the weather,plant diseases,and trade restrictions,which hinders its further application.On the other hand,2-PE can also be chemically synthesized through ethylene oxidation of benzene or reduction of styrene oxide.Chemical synthesis processes are generally operated under harsh conditions,such as high temperature,high pressure,and strong acid or alkali environments,producing many undesirable by-products,such as ethylbenzene and styrene.This not only increases the downstream costs,but also seriously debases the grade of 2-PE.The increasing demand for environmental friendly processes and the preference for“natural”products from consumers have considerably stimulated the development of biological production of flavors and fragrances.Biological synthesis of 2-PE has attracted extensive attention because it meets the requirements of environmental friendliness and also satisfies the definition of“natural”products.However,the toxicity of 2-PE to cells is a critical limiting factor for the biosynthesis of 2-PE.In this review,we have comprehensively summarized the current status and perspectives for biological 2-PE production in terms of its advantages over classical chemical synthesis and extraction from natural plants.A comprehensive description of 2-PE synthetic pathways and global regulation mechanisms,strategies to increase 2-PE production,and the utilization of agro-industrial wastes as feedstocks has been systematically discussed.Furthermore,the application of in situ product removal techniques in 2-PE biosynthesis has also been highlighted.