Mutagenesis Breeding Of Yeast Strain For Production Of2-phenylethanol

2–phenylethanol as an aromatic alcohol is widely used in food, tobacco,cosmetics and dailychemical products and so on.Due to the cancer of the raw materials of2-phenylethanol and therenewal of the ideal on people’s health, people began to seek a new, non-polluting productionmodel to replace the old mode of production.Foreign scholars found that the yeast canbiosynthesize high concentrations of2–phenylethanol by adding the precursor ofL-phenylalanine to the nutrient medium.They have made a deep study in all ways since then. InChina, research in this field of science is beginning to carry out. By comparing the tolerance ofYeast Strains to the2-phenylethanol and by the way of the ultraviolet radiation, hoping tofinding out a higher tolerance, higher yield strain, our studies provide scientific reference for theresearch and development to2-phenylethanol. The results are as below.1.Comparing the tolerance of three Yeast Strains to the2-phenylethano provided by ourlaboratory: By studing the effects of different2-phenylethanol concentration on the growth ofyeasts, the results show that the Saccharomyces cerevisiae, Candida tropicalis and Candidautilis yeast can grow in the case of concentration of2-phenylethanol at2g/L. However, onlySaccharomyces cerevisiae can grow in the case of concentration of2-phenylethanol at3g/L. Sothat Saccharomyces cerevisiae is significantly higher tolerance than the others.2.UV mutagenesis breeding techniques for Saccharomyces cerevisiae B0: By the way of theultraviolet radiation and separation, a mutated strain named B1was screened out, whosetolerance to2-phenylethanol had increased by15%over the original strain. It gained the yield of2-phneylethanol at2.3g/L at the top level, which had increased by4.5%over the original strain.3.Designing and optimizing the culture medium: In the condition of L-phenylalanine at10g/L, wort at160g/L, yeast at2g/L, magnesium sulfate0.5g/L, pH at6, temperature at24℃,time at84h, shaking speed at100-200r/min, bacteria concentration at1-1.3*10~8cfu, mutatedstrain B1gained the yield of2-phneylethanol at3.18g/L at the top level, which had increased by44.5%over the original strain.These results provide a foundation for the biosynthesis of2-phenylethanol further.