Abstract: β-phenylethanol(β-PE) is a higher aromatic alcohol with a rose-like odour. The fragrance of the rose is highly popular and desired, making β-PE the most-used fragrance chemical in perfume and cosmetics. It is also used in flavor compositions for food. Most of the world's annual production of several thousand tons is synthesized by chemical means but, due to increasing demand for natural flavors, alternative production methods are being sought. Harnessing the Ehrlich pathway of yeasts by bioconversion of L-phenylalanine to β-PE could be an good option.
In this work, systematic studies were carried out on the screening of yeast strains which can transform L-phenylalanine to β-PE; determination, isolation, purification, identification, quantification method of β-PE Kluyveromyces marxious was screened from the microorganism strains preserved by our laboratory. According to the chemical structures of L-phenylalanine and β -phenylethanol, we established some methods for the separation and determination of them: RP-HPLC method for the separation and determination of L-phenylalanine and β-phenylethanol, this method was accurate, sensitive and reliable.
The conditions of liquid fermentation of β-PE were studied. It showed that the effect of single factors, such as carbon source, nitrogen source, growth factors and inorganic salts on the production of β-PE. Through orthogonal test, the optimum medium composition had been obtained. It was 35g/L sucrose, 6g/L L-phenylalanine, 0.4g/L KH2PO4 and 1.8g/L YNB. The optimum shaking culture condition was as follows: 24 hours strain age, 6% inoculation quantity, initial medium pH=5.48, 50 mL medium in 250mL shaking flask, 28℃, 220r/min shaking speed, 48 hours incubation.
Keywords: Kluyveromyces marxious ,bio-transform, L-phenylalanine, β-PE
