Composting Research Group, Department of Chemical, Biological and Environmental Engineering, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Barcelona, Spain.
Appl Microbiol Biotechnol. 2018 Jun;102(11):4703-4716. doi: 10.1007/s00253-018-8964-y. Epub 2018 Apr 7.
2-Phenylethanol (2-PE) and 2-phenethyl acetate (2-PEA) are important aroma compounds widely used in food and cosmetic industries due to their rose-like odor. Nowadays, due to the growing demand for natural products, the development of bioprocesses for obtaining value-added compounds has become of great significance. 2-PE and 2-PEA can be produced through the biotransformation of L-phenylalanine using the generally recognized as safe strain Kluyveromyces marxianus. L-phenylalanine bioconversion systems have been typically focused on submerged fermentation processes (SmF), but there is no information about other alternative productive approaches. Here, the solid-state fermentation (SSF) of sugarcane bagasse supplemented with L-phenylalanine was investigated as a sustainable alternative for producing 2-PE and 2-PEA in a residue-based system using Kluyveromyces marxianus as inoculum. An initial screening of the operational variables indicated that air supply, temperature, and initial moisture content significantly affect the product yield. Besides, it was found that the feeding strategy also affects the production and the efficiency of the process. While a basic batch system produced 16 mg per gram of residue (dry basis), by using split feeding strategies (fed-batch) of only sugarcane bagasse, a maximum of 18.4 mg g were achieved. Increase in product yield was also accompanied by an increase in the consumption efficiency of nutrients and precursor. The suggested system results as effective as other more complex SmF systems to obtain 2-PE and 2-PEA, showing the feasibility of SSF as an alternative for producing these compounds through the valorization of an agro-industrial residue.
2-苯乙醇（2-PE）和 2-苯乙醚（2-PEA）是重要的香气化合物，因其玫瑰般的气味而广泛应用于食品和化妆品行业。如今，由于对天然产品的需求不断增长，开发用于获得增值化合物的生物工艺变得非常重要。2-PE 和 2-PEA 可以通过使用被普遍认为安全的菌株克鲁维酵母（Kluyveromyces marxianus）转化 L-苯丙氨酸来生产。L-苯丙氨酸生物转化系统通常集中在分批发酵过程（SmF）中，但没有关于其他替代生产方法的信息。在这里，研究了用 L-苯丙氨酸补充的甘蔗渣的固态发酵（SSF）作为使用克鲁维酵母作为接种物在基于残渣的系统中生产 2-PE 和 2-PEA 的可持续替代方法。操作变量的初步筛选表明，空气供应、温度和初始水分含量显著影响产物产率。此外，还发现进料策略也会影响生产和过程效率。虽然基本分批系统每克残渣（干重）可产生 16 毫克，但通过使用仅甘蔗渣的分批进料策略（分批补料），可获得最高 18.4 毫克/克。产物产率的增加伴随着营养物和前体的消耗效率的提高。所提出的系统与其他更复杂的 SmF 系统一样有效，可以获得 2-PE 和 2-PEA，表明 SSF 作为通过农业工业残渣的增值来生产这些化合物的替代方法是可行的。
