【作者】 薛小波；

【导师】 张小里；

【作者基本信息】 西北大学 ， 工业催化， 2009， 硕士

【摘要】 光学纯(R)-β-羟基异丁酸(R-HIBA)是医药、食品和精细化工产品的重要手性中间体。因其具有重要的应用价值,已引起人们的广泛兴趣。利用化学法对甲基丙烯酸进行选择性催化氧化是制备(R)-β-羟基异丁酸的一个重要方法,但是存在收率低、副产品多、环境污染严重、工业化生产成本昂贵等缺点。本文通过对皱落假丝酵母不对称催化氧化异丁酸(IBA)生产(R)-β-羟基异丁酸进行研究,从优化生物发酵条件以及工艺方面,对生物法催化氧化反应条件进行了较系统的研究并建立了以气相色谱(GC),氢焰检测器(FID)为主的检测方法。本文利用酵母全细胞催化转化(R)-β-羟基异丁酸,所以菌体生物量对其催化氧化的影响很大。通过对皱落假丝酵母自然选育以及紫外诱变对菌体进行改良,得到了高产菌株比原始菌株细胞量提高14.3%,产物(R)-β-羟基异丁酸产量提高18%。通过对培养基条件和反应条件进行优化得出:底物IBA浓度为20g/L,葡萄糖浓度为30g/L,pH值为7.3,装液量在20%(v/v)条件下更有利于菌体的生长和转化。通过补料半批式发酵,按照优化条件对反应体系进行调控,经过112h培养,产物R-HIBA浓度达到60.9g/L,其平均生产率为0.356g/(L·h),IBA摩尔转化率达到41.2%。本文所研究底物和产物均为有机酸,极性都比较高,还具有易吸附、高沸点、难汽化等特点,所以在对发酵液进行处理后,对样品进行酯化处理,使它们极性变小,沸点变低、有利于处理和检测采用标准图谱,添加底物和产物标准品比较对照的方法进行定性分析,并确立了以三氯甲烷为内标物的内标法进行定量测定。并对产物进行比旋光度和红外光谱测定。更多还原

【Abstract】 Optical-pure(R)-β-hydroxyisobutyric acid(R-HIBA) is an important chiral building block in medicine,food and fine chemical products.It has attracted interest widely because of its important commercial interest.It is an important method to catalytic oxidate selectively methylacrylic acid to product R-HIBA by chemical synthesis.Howere,there are some shortage,such as low-yield,high costs,lot of by-products and serious pollution.In this study, production of R-HIBA from isobutyric acid was investigated using Candida rugosa.It studies more systematically the condition of Biological oxidation in term of optimize Bio-fermentation conditions and technology,and The gas chromatogram(GC) with FID(Fire iron deteteetor) was applied to detect and analyze their appearance.In this study,R-HIBA is synthesized through the method of Yeast whole-cell catalytic convertion,so biomass has a considerable effect on bio-catalytic oxidation.The Candida rugosa was improved by UV-induction and isolating and screening method.High-yield mutant was obtained,which increases the biomass by 14.3%,with the yield of product of the R-HIBA increased by 18%compared with the parent strain.After optimizing the conditions and system of reaction,a conclusion was drawn:It was advantageous to cell growth and coversion of R-HIBA production,when the concentration of substrate(IBA),Glu density was 20g/L and 30g/L,respectively,pH was 7.3,the volume of liquild was maintained 20%(v/v).Through the fed-batch fermentation,the reaction system was controlled according to the optimization conditions.when the culture time reached 112h,the concentration of production of R-HIBA was up to 60.9g/L,with the average productivity 0.356 g/L and the molar conversion yield of 41.2%.Since substrate and product are organic acids and both of them have a higher polarity, easy adsorption,high boiling point,hardness to vaporize et.the samples were first derived for the esters,which is beneficial to treat and test.The sample of substrate and product were analyzed qualitatively comparing with gas cheromatographic chart of standard,and the internal standard method was used to determine their quantity of sample,with chloroform as internal standard sample.Specific rotation and IR was measured for the product.更多还原