【作者】 朱晓萍； 刘志彬； 张晨； 张雯； 倪莉；

【Author】 Zhu Xiaoping;Liu Zhibin;Zhang Chen;Zhang Wen;Ni Li;Institute of Food Science and Technology,Fuzhou University,Fujian Center of Excellence for Food Biotechnology;

【机构】 福州大学食品科学技术研究所福建省食品生物技术创新工程技术研究中心；

【摘要】 茶多酚具有强抗氧化性,且对真菌抑菌效果不强,本试验首次将其作为一种调控因子,研究茶多酚对红曲霉生长、色素合成及其关键调控基因表达量的影响。结果表明:不同浓度茶多酚对红曲霉产色能力影响不同,当茶多酚浓度为2.33 mg/mL时,红曲霉色素产量最大。跟踪发酵过程中色价、生物量、pH值和残糖含量等指标变化情况,结果显示对照组色素产量在第三天达到最大值54.02 U/mL,而实验组继续累积,到第五天达到最大值101.68 U/mL,茶多酚显著延缓了红曲菌的生长和3种色素的合成,发酵结束时总色价提高1.03倍,黄色素比例提高7.4%。采用qPCR分析茶多酚对红曲色素生物合成相关的10个调控基因(包括mpPKS5、mpFasA2、mpFasB2、mppB、mppR1、mppR2、mppA、mppC、mppE和mppD)表达的影响。结果表明发酵第2天茶多酚使mpPKS5、mppB、mppA、mppC、mppE和mppD基因上调,第4天时实验组的10个基因的表达水平分别上调2.04、5.12、1.66、0.95、4.11、0.12、1.63、1.44、1.97和0.94倍(P<0.05),整体基因表达量的变化和色素累积的趋势一致。更多还原

【Abstract】 Tea polyphenols have strong antioxidant activity,and have no strong inhibitory effect on fungi.In this study,tea polyphenols were used as intervention factors to study the effects of tea polyphenols on growth,pigment production,and expression of pigment key regulatory genes in Monascus.The results are as follows:different concentrations of tea polyphenols have different effects on the yield of Monascus pigment.When the content of tea polyphenols was 2.33 mg/mL,the total color value of the experimental group was highest.We tracked the changes of color value,biomass,pH value,and residual sugar content during the fermentation process.The pigment yield in the control group reached a maximum of 54.02 U/mL on the third day,while the pigment in the experimental group continued to accumulate until the fifth day reached a maximum of 101.68 U/mL.The results showed that tea polyphenols significantly retarded the growth of Monascus and the biosynthesis of 3 kinds of pigments.At the end of fermentation,the total color value and the yellow pigment ratio were increased by 1.03 times and 7.4%.The effects of tea polyphenols on the expression of 10 regulatory genes on the biosynthesis of Monascus pigment(including mpPKS5,mpFasA2,mpFasB2,mppB,mppR1,mppR2,mppA,mppC,mppE and mppD) were analyzed by qPCR.The results showed that tea polyphenols significantly increased the gene expression level of mpPKS5,mppB,mppA,mppC,mppE and mppD on the second days.On the fourth day,the expression level of 10 genes was increased by 2.04,5.12,1.66,0.95,4.11,0.12,1.63,1.44,1.97 and 1.44 times,respectively(P < 0.05).The change of total gene expression was consistent with the trend of pigment accumulation.更多还原