Production of 2-phenylethanol, a flavor ingredient, by Pichia fermentans L-5 under various culture conditions

摘要

Production of 2-phenylethanol by Pichia fermentans L-5 as affected by cultivation temperature (20-40℃), medium pH (4.0-11.0) and shaking speed (0 250 rpm) as well as the kinetics of 2-phenylethanol formation during fermentation were investigated in the present study. Results showed the optimum culture temperature. initial medium pH and shaking speed for the 2-phenylethanol production by test organism were 30-35℃. 8.5 and 250 rpm. respectively. Kinetics study revealed that production of 2-pheny- lethanol during P. fermentans L-5 fermentation increased almost in parallel with the increase in biomass or viable population dur- ing the initial stage of fermentation. During a 72--h fermentation period. level of phenylalanine in medium dropped coincidentally with increasing biomass and 2-phenylethyl derivatives, from the start of fermentation. A maximum 2--phenylethanol production of ca 505.5 mg/l with a molar yield of ca 0.74 was obtained after 16 h of fermentation.