Metabolic Engineering Of Saccharomyces Cerevisiae For Production Of 8-dimenthylally Naringenin

8-dimenthylallynaringenin(8DN)is a flavonoid which is mainly distributed in leguminosae,moraceae,asteraceae and a few other plant families.Because of its strong activity of antioxidant and antibacterial,it is valuable to the research of human disease and pharmacology,which is usually used to eliminate inflammation and analgesic effect,suppress tumor growth and treat cardiovascular and cerebrovascular diseases like CHD.Furthermore,8DN is the important precursor for producing the flavonoids medicine Icaritin,which has potential applications in the area of pharmaceutical synthesis.The biosynthesis of 8DN is realized by five biocatalytic reactions,and solving the problem of the optimization and adaptability among of the genes in the metabolic pathway is the key factor of achieving its synthesis in vivo.As the complexities of its synthesis pathway and related genes,there is no report about the total synthesis in vivo.This study used Delta integration to transfer the genes(TAL?4CL?CHS?CHI)of naringenin synthesis to build 30 strains for naringenin production,and we found that the different assembling will cause the production difference(0.37mg/L-22.34mg/L).On the basics of the strain with the highest yield(SyBE_Sc02050003),we transfered the multiple copies plasmid carried prenyltransferase gene from Sophora flavescens,and produced 8DN for 36.7?g/L after fermentation in shaking flask.Compared this production to that of naringenin feeding,we found that the supply of naringenin was not key factor of affecting the 8DN production.Consequently,we made a strategy of the optimization and truncation for N8 DT protein sequence,and found that this method could improve catalytic effect of this key reaction to reach the production of 52.6?g/L(11.9?g/g).This work realized the synthesis of 8DN from tyrosine in Saccharomyces cerevisiae firstly,and realized the improvement of enzyme catalytic efficiency by optimizing protein sequence of the core gene,which had an important guiding significance which provided an reference for synthesis of other natural flavonoids in microbials.