Studies On The Production Of 2-Phenylethanol By S.cerevisiae CWY132

2-phenylethanol (2-PE), an aromatic alcohol with a rose-like smell, is one of the most used flavors in food and cosmetic industries. Since natural PEA is preferred by more and more people, the production of natural PEA by yeast is the way to reach greater market prospect and application value.In this study, a mutant S. cerevisiae CWY132 with high yield of 2-phenylethanol in the batch culture was taken as object. To investigate the relations between mutation sites and 2-phenylethanol yield, the genes of ARO8, ARO9 and ARO10 from S. cerevisiae CWY132 were cloned and sequenced, respectively. Compared with the initial strain S.cerevisiae AS 2.516, two mutation sites in ARO9 and two mutation sites in ARO10 were identified, respectively. When mutated ARO9 and ARO10 introduced into the yeast WHU2a, the yield of 2-phenylethanol was increased 17.2% and 20.1%, respectively. These mutations were concluded to be responsible for the increase of 2-phenylethanol yield.Effects of biotransformation conditions on the production of 2-phenylethanol by this mutant were also analyzed. Under the optimum condition, the yield of 2-phenylethanol reached up to 3.98 g/ L , increased by 109% compared with the original 1.9 g/ L . 5L Biostat fermentor test was also carried out, with the the yield of 4.1 g/L 2-phenylethanol in the culture.High concentration of 2-phenylethanol has intense inhibition effect on the growth of yeast cells, which would in turn restrict the production of 2-phenylethanol. ISPR has been proved to be an effective approach to remove the inhibition effect. Using molasses as carbon source, we’ve studied the ISPR system on the transformation of 2-phenylethanol. Combined with fed-batch cultivation, 9.03 g/L of 2-phenylethanol has been achieved on shake flask test, effectively removing the inhibition of 2-phenylethanol on yeast cells.