GFP工程酵母菌的构建及其对Cu^(2+)的荧光响应

从酿酒酵母基因组DNA中克隆到金属硫蛋白启动子(PCUP1)片段,将绿色荧光蛋白(GFP)基因置于PCUP1的调控下,构建重组质粒pCUP9K-GFP,并通过氯化锂法转化毕赤酵母,获得工程菌株。工程菌细胞及其发酵液中可检出GFP荧光,表明PCUP1能启动外源基因GFP转录,使工程菌表达并分泌GFP。研究发现,工程菌培养液中分别加入10μmol/L的铜、铬、镉和砷离子后,铜处理组GFP荧光强度明显增加,其余三种离子对工程菌荧光强度影响不大;用铜离子诱导后,工程菌发酵上清液的荧光强度明显增强,并与铜离子浓度(0～1mmol/L)呈正相关。研究表明,该工程菌中启动子PCUP1受铜离子诱导,GFP的表达对铜离子具有剂量依赖性,在一定浓度范围内,GFP荧光强度与铜离子浓度呈正相关。

活性菌肽豆蛋白喷雾干燥工艺研究

活性菌肽豆蛋白中既含有促生长的工程酵母菌,又含有豆粕降解的肽类物质,是种新型蛋白饲料。为了使活性菌肽豆蛋白广泛地应用到水产配合饲料中,本试验采用正交试验探讨喷雾干燥工艺——进风温度、进风速度和进样速度对其中工程酵母菌的存活率的影响。结果表明,这三种因子都明显影响工程酵母菌的存活率,其作用大小依次为进风温度>进样速度>进风速度。最优喷雾干燥条件组合为:进风温度为120℃、进风量为1.10 m3/min、进样速度为12.00 ml/min。在最优的干燥条件下,活菌数高达2.10×1010CFU/g,存活率为28.54%。

毕赤酵母基因工程菌产植酸酶发酵条件的研究

该试验对毕赤酵母基因工程菌产植酸酶的发酵条件作了初步的研究,分别对接菌量、接菌种龄、诱导发酵pH及甲醇添加量进行了研究与分析。

Recent advances in metabolic engineering of microorganisms for production of tyrosol and its derivatives

Tyrosol is a natural phenolic compound with antioxidant,anti-inflammatory and other biological activities,serving as an important precursor of high-value products such as hydroxytyrosol and salidroside.Therefore,the green and efficient biosynthesis of tyrosol and its derivatives has become a research hotspot in recent years.Building cell factories by metabolic engineering of microorganisms is a potential industrial production way,which has low costs and environmental friendliness.This paper introduces the biosynthesis pathway of tyrosol and presents the key regulated nodes in the de novo synthesis of tyrosol in Escherichia coli and Saccharomyces cerevisiae.In addition,this paper reviews the recent advances in metabolic engineering for the production of hydroxytyrosol and salidroside.This review can provide a reference for engineering the strains for the high-yield production of tyrosol and its derivatives.