放射型根瘤菌分批发酵生产辅酶Q10的代谢特性和发酵动力学

以放射型根瘤菌WSH2601作为辅酶Q10分批发酵的试验菌,对其代谢特性进行了初步研究。对分批发酵过程中细胞生长、产物积累、糖消耗、中间产物有机酸及pH的变化规律进行了描述：由Logistic模型方程分别建立了放射型根瘤菌辅酶Q10发酵过程细胞生长、产物合成及基质消耗随时间变化的数学模型。模型模拟计算结果与实验值能较好地吻合。动力学研究结果表明该模型能较好地反映放射型根瘤菌的细胞生长、底物消耗和产物合成过程及其动力学机制。辅酶Q10分批发酵中细胞生长与产物合成属于半偶联型。     

均匀设计法优选辅酶Q10的超声提取工艺

用均匀设计法优化了以新鲜烟叶为原料,超声提取辅酶Q10的工艺。考察了超声时间、温度、液料比和超声功率4个因素对辅酶Q10提取率的影响,并对提取过程用多元回归方程进行了数值模拟。实验得到优化的辅酶Q10超声提取工艺条件为:提取溶剂体积分数85%乙醇,液料体积质量比18 mL/g,超声温度45℃,超声时间45 m in,超声功率250 W。结果表明,超声法提取对烟叶中辅酶Q10的提取质量分率为7.12×10-6,其提取率是索氏提取的1.34倍,实验结果与回归方程的拟合值吻合良好,说明应用超声法提取烟叶中的辅酶Q10是可行的。     

Z5-G菌生产聚β-羟基丁酸发酵动力学模型

研究了Z5 G菌株在 3L搅拌发酵罐中以蔗糖为碳源分批发酵生产聚β 羟基丁酸 (PHB)的生长特性。在Lo gistic方程和Luedeking Piret方程的基础上,建立了Z5 G菌发酵过程中菌体生长、基质消耗、产物形成的动力学模型。应用MathCAD软件处理实验数据和模型,拟合出所有模型参数,建立了动力学模型,经过验证模型预测值和实验值吻合较好,表明此动力学模型对指导PHB的发酵生产具有实际意义。     

中性β-甘露聚糖酶分批发酵动力学研究

以魔芋粉为碳源,研究了10 L自控发酵罐中枯草芽孢杆菌TJ-200603分批发酵产中性β-甘露聚糖酶的过程动力学。实验数据表明,菌体生长呈现典型S型曲线,而酶的合成与菌体生长同步进行,属于生长耦联型。基于这些过程曲线的变化规律,构建了β-甘露聚糖酶分批发酵过程的动力学模型。并经非线性拟合和优化,获得了最佳的模型参数值,最终确定了能够较好表征实际发酵过程中菌体细胞生长、产物β-甘露聚糖酶合成以及基质总糖消耗的3个动力学方程。     

伴有辅酶再生过程的Saccharomyces cerevisiae B5不对称还原2'-氯-苯乙酮的催化反应动力学

对以5%(体积比)乙醇为辅助底物的伴有辅酶再生过程的SaccharomycescerevisiaeB5不对称还原2'-氯-苯乙酮制备手性药物中间体R-2'-氯-1-苯乙醇的生物催化反应建立了描述底物消耗和产物合成的动力学模型.考察了反应过程中辅酶的种类和含量,以及底物和产物随时间的变化量.研究表明,参加反应的还原剂是辅酶Ⅰ.当底物初始浓度≤8.09mmol·L-1,可不考虑底物对微生物的毒害作用,反应可看作两个均符合顺序反应机制的氧化还原反应的耦联.通过实验数据对动力学方程式的拟合,得到动力学参数Vm1=8.0×10-4mol·L-1·h-1,KmB1=9.0×10-4mol·L-1,KiA1=2.0×10-6mol·L-1.动力学模型模拟计算结果与实验值能较好地吻合.     

中国红豆杉悬浮细胞培养的发酵动力学模型

通过对 10L发酵罐中中国红豆杉细胞培养的代谢动力学分析 ,建立了细胞生长、底物消耗、紫杉醇合成动力学模型 ,并应用实验数据回归了动力学模型参数 ,并将模型预测值与实验值进行比较。结果表明 ,模型预测值与实验值较吻合     

辅酶Q10的合成与应用

以茄尼醇、异戊二烯和辅酶Q0作为主要原料,通过溴化、加成和缩合3步反应合成了目标产物辅酶Q10.其中溴化和加成反应一次收率分别为95%和90%,缩合反应重复收率在70%左右.生产规模为5kg/次.并介绍了辅酶Q10的应用和市场需求.     

生物转化法生产2-苯乙醇动力学研究

考察了酿酒酵母(Saccharomyces cerevisiae)在5L发酵罐中转化生成2-苯乙醇过程中的菌体生长、产物生成和基质消耗的变化规律,并基于得到的实验数据,建立了转化过程中菌体生长的Logistic模型、2-苯乙醇生成的Luedeking-Piret模型和蔗糖消耗的Luedeking-Piret相似模型。将3个动力学模型的理论值和实验值进行了比较,表明模型具有较高的拟合精度,能准确反映2-苯乙醇生物转化过程及其动力学特征,可用于酿酒酵母转化生产2-苯乙醇过程的预测。     

天蓝色链霉菌产蓝色素的分批发酵动力学分析

在分批发酵中，研究了天蓝色链霉菌的生长、基质消耗及蓝色素分泌的特性. 基于Logistic方程和Luedeking-Piret方程，得到了描述分批发酵过程的动力学模型及模型参数，同时对实验数据与模型进行了验证比较. 模型计算值与实验数据拟合良好，模型基本反映了天蓝色链霉菌分批发酵过程的动力学特征.     

产1,3-丙二醇克雷伯氏菌诱变菌株的发酵动力学研究

克雷伯氏菌是1,3-丙二醇(1,3-PD)生产菌。根据产酸克雷伯氏菌的诱变菌株Y-37的发酵过程曲线,对克雷伯氏菌生产1,3-PD的发酵动力学特性进行研究,提出了发酵过程中菌体生长、1,3-PD生物合成、甘油消耗的动力学模型,并应用matlab数值应用软件对实验数据进行拟合。该模型基本上能够描述克雷伯氏菌的发酵过程,模型的计算值与实验测定值能够比较好地拟合。     

间歇结晶器中地塞米松磷酸钠溶析结晶动力学的研究

在间歇结晶器中,利用矩量变换法对地塞米松磷酸钠溶析结晶过程动力学进行了理论研究。由实验得到的地塞米松磷酸钠晶体的粒数密度分布数据,采用非线性最小二乘法分别对与粒度相关和与粒度无关线性生长速率模型进行了参数估值,通过由各种模型得到的晶体生长速率的计算与实验值的比较,发现与粒度无关生长速率模型不仅计算过程简单且计算的精度也更好。最后,以与粒度无关生长速率模型为基础,由不同实验条件下晶体的粒数密度分布数据非线性回归出其成核速率方程和生长速率方程。对方程的理论分析表明,低过饱和度、低悬浮密度和较高的结晶温度有利于得到平均粒径更大的地塞米松磷酸钠晶体。     

沙雷氏菌Serratia sp.BK-98发酵生产2-酮基-D-葡萄糖酸的工艺优化及动力学研究

Based on the optimization of culture conditions for producing 2-keto-D-gluconic acid(2-KDG)by Serratia sp.BK-98 in a Erlenmeyer flask, the factors of dissolved oxygen(DO)and pH affecting 2-KDG batch fermentation in 100 L fermenter were further optimized to be 30% and 6.0 respectively.Under the DO-stat and pH-stat batch culture conditions, 2-KDG production reached 211.2 g·L^-1.The kinetics of DO-stat and pH-stat batch fermentation were also investigated and the models for biomass, substrate consumption and product were established respectively based on the Logistic equation, Leudeking-Piret equation and Modified Leudeking-Piret equation.Curve fittings for the above models by using experimental data were performed by the non-linear least squares method with the software Origin 8.0.With the evaluated model parameters, the calculated values of the models and experimental data were in good agreement and the models could provide guidance for 2-KDG fermentation production.     

沙雷氏菌Serratia sp.BK-98发酵生产2-酮基-D-葡萄糖酸的工艺优化及动力学研究

引言 2-酮基-D-葡萄糖酸(2-KDG)有着广泛的用途,它能被用作食品添加剂、水泥增塑剂、洗涤剂,是照片显影剂的重要成分[1];同时它也是除草剂[2]、D-核酮糖、D-阿拉伯糖,特别是D-异抗坏血酸合成过程中的重要前体.     

重组大肠杆菌分批-补料高密度发酵生产类人胶原蛋白的动力学

The kinetics of batch and fed-batch cultures of recombinant Escherichia coli producing human-like collagen was investigated. In the batch culture, a kinetic model of a simple growth-association system was concluded without consideration of cell endogeneous metabolism. The cell lag time, the maximum specific growth rate and growth rates were set at (0.15, 0.2, 0.25h-1) by the method of pseudo-exponential feeding, and the expressions for the specific rate of substrate consumption, the growth kinetics and the product formation kinetics of each phase spectively. The model predictions are in good agreement with the experimental data.     

Mathematical model for lactic acid production from lactose in batch culture: Model development and simulation

The models available to describe lactic acid production do not seem to fit the experimental data very well, especially at the end of batch cultures. From a careful analysis of batch data, an unstructured model of the process has been derived, in which the specific growth rate variations and lactic acid concentration with time have been described by complemented logistic functions. Also, an additional term has been introduced into the Luedeking–Piret expression, taking into account the reduction in rate of lactic acid production observed at very low growth rate.     

Kinetic Study and Mathematical Modelling of the Growth of S. cerevisiae 522D in Presence of K2 Killer Protein

This paper deals with the study of the kinetics of batch fermentations for a sensitive strain of S. cerevisiae growing in a culture medium containing K2 killer protein. The inhibition due to the killer toxin was measured by the reduction of the viable biomass, ethanol production and glucose consumption compared with a reference fermentation. The reference culture was run under the same conditions, but using a heat-denatured solution of killer protein. Results showed a decrease of the viable population of 67·8% after 15 h incubation. The fermentation time for the total consumption of the glucose was significantly affected by the presence of the killer toxin. The specific rate of ethanol production was also affected during the fermentation. However, the yields of ethanol and biomass were very similar for both fermentations. A kinetic mathematical model was proposed to explain the dynamics of the S. cerevisiae 522D growth in the presence of the K2 killer protein. The results of the suggested simulation were in agreement with the experimental data. © 1997 SCI.     

温度对产甘油假丝酵母产甘油发酵过程的影响

研究了温度对产甘油假丝酵母分批发酵生产甘油及其生长动力学的影响。结果表明:在温度为28—36℃时,由于发酵周期随温度升高而显著缩短,导致细胞生长、甘油合成和葡萄糖消耗的比速率也随温度升高逐渐增加;当温度为32℃时最适于产甘油假丝酵母合成甘油,甘油产量、得率和产率分别达到120.3 g/L,0.523 g/g,1.43 g/(L.h);应用Logistic方程对细胞生长动力学进行了模拟,获得不同温度下的生长动力学参数;根据细胞生长动力学参数,得到28—36℃时甘油分批发酵过程中细胞质量浓度同温度、时间之间的一般关系式,经验证该模型在28—36℃范围内可用于预测不同温度下的细胞生长情况。     

Identification of the breakage rate and distribution parameters in a non-linear population balance model for batch milling

Non-linear population balance models (PBMs), which have been recently introduced due to the limitations of the classical linear time-invariant (LTINV) model, account for multi-particle interactions and thus are capable of predicting many types of complex non-first order breakage kinetics during size reduction operations. No attempt has been made in the literature to estimate the non-linear model parameters by fitting the model to experimental data and to discriminate various models based on statistical analysis. In this study, a fully numerical back-calculation method was developed in the Matlab environment to determine the model parameters of the non-linear PBM. Not only does the back-calculation method identify the parameters of complicated non-linear PBMs, but also it gives the goodness of fit and certainty of the parameters. The performance of the back-calculation method was first assessed on computer-generated batch milling data with and without random error. The back-calculation method was then applied to experimental batch milling data exhibiting non-first order effects using both the LTINV model and two separate non-linear models. The back-calculation method was able to correctly determine the model parameters of relatively small sets of batch milling data with random errors. Applied to experimental batch milling data, the back-calculation method with a two-parameter non-linear model yielded parameters with reasonable certainty and accurately predicted the slowing-down phenomenon during dry batch milling. This study encourages experimenters to use advanced non-linear population balance models along with the back-calculation method toward estimating the breakage rate and distribution parameters from dense batch milling data sets.     

碳酸锂结晶动力学研究

为了更好地指导生产,采用无蒸发恒容间歇反应器对Li2CO3自LiHCO3溶液中的结晶动力学进行了研究。实验结果表明,温度的升高及质量浓度的增大能显著提高结晶速率,低的系统压力及搅拌有利于结晶反应的进行。根据实验数据拟合得到了该结晶过程的宏观动力学方程。晶体的生长机制表明,扩散控制机制是Li2CO3自LiHCO3溶液中生长的主导机制。