Optimization Of Amplification Conditions On Microbial Transforming Cinnamic Acid To Acetophenone And Its Fermentation Kinetics Analysis

In this paper, the pilot-plant-scale biocatalysis experiment for using Mucor.sp. to transform cinnamic acid into acetophenone in a home-made50L fermentation tank was studied. A whole system which contains analytical method, fermentation process, extraction process and kinetic analysis was established gradually. Main results are shown as follows:(1) A quantitative and convenient analysis method by UV spectrophotometry was established to determinate the relative percentage of CMA and APO in bioconversion broth, based on proving the background orption of fermentation broth has no obvious change. The influence of the background orption of fermentation broth were minimized by this determination method. The relative standard deviations of CMA and APO were1.02%and1.45%, and the average recoveries were101.34%and99.94%, respectively.(2) A reaction kettle was refitted to become a50L mechanical agitated fermentor by adding some special parts, and the optimal fermentation conditions of transforming cinnamic acid into acetophenone was determined in this fermentor. The detail data were as follow:rotate speed110r/min, transformation time96h,and the transformation of cinnamic acid was93.32%.(3) The biocatalysis experiment for transforming acetophenone into1-phenylethanol in a1.5L fermentation tank was studied. The optimal fermentation conditions were shown as follow:rotate speed was120r/min, transformation time was72h, and the transformation of acetophenone was16.3%.e.e. value87%。(4) The optimal extraction conditions of tradition solve extraction method were determined as followed:ethyl acetate as extraction solvent, volume ratio of aqueous phase and organic phase of4:3, extraction times for the first time. The extraction of acetophenone was99.04%.(5) A pilot-plant-scale water vapor distillation-solvent extraction device was made for the extraction of the acetophenone from ferment liquid, and the related process parameters were as follow:10L ferment liquid,600mL ethyl acetate, the temperature of conduction oil was105℃, the distillation speed was0.18mL/s, distillation time was16h. The extraction rate, purity, and productivity was90.4%,89.78%, and84%, respectively.(6) The fermentation kinetics of acetophenone production by Mucor.sp. in50L fermenter was investigated. A series kinetic model for microorganism growth, acetophenone formation and substrate consumption during fermentation were constructed, based on the Logistic equation. Then the data was analyzed to generate the kinetics parameters of acetophenone production with batch fermentation. The experimental data and theoretical models were compared. The results showed that the theoretical models could fit the experimental data well, and the model appeared to provide a reasonable description for the action mechanism of related enzyme and the batch fermentation process.