Study On Analytical Methods Of Parameters In The Fermentation Broth And Technology To Produec D-Ribose By Fermentation

D-ribose, which is an important constituent of DNA, some coenzymes and vitamins, has extensive usages in foodstuff and medicine field. In recent years, D-ribose, a kind of raw material for new medicines of anticancer and antivirus, shows good perspective for application. Interest in fermentation by microorganism has recently increased as a result of its little byproducts, low cost and high yield. In this paper, according to D-ribose fermentation properties, the measurement methods of parameters in fermentation process were studied, the cell strain of fermentation was screened, the different statistical methods of optimizing media was adopted and compared, and dynamics model was constructed.1. The method of measurement of D-ribose concentration in the fermentation broth by spectrophotometry has been studied. According to the principle of D-ribose measurement by spectrophothmetry, the main factors affecting correct measurement of D-ribose concentration in the fermentation broth were obtained. The optimum measured wavelength is 670 nm, the heating time 25 min and the hydrogen ion concentration 8 mol . L-1. Absorbance A shows remarkable linear relationship to D-ribose concentration in the range of 10-30 ug.ml-1. Effect caused by the non-glucose element in the fermentation broth can be ignored and glucose significantly influences the measurement of D-ribose. The effect of glucose concentration on A was obtained through experiments. An effective method was established to measure D-ribose concentration in microbial fermentation broth by spectrophotometry.2. A quick, accurate and simply absorbance measurement method for the cell growth curve (including seed solution and broth) was investigated, and the function relation between the cellular concentration and absorbance was established, which provides the foundation for the measuring online of cellular concentration in industry and metabolism control of producing D-ribose by fermentation.3. Natural screening and UV-mutation were applied to experimental cell strain. UV-mutationcould obtain higher yield strain than natural screening and the latter was only suitable to conserve cell strain. According to the usual standard that 70% death ration is suitable, 30s is the appropriate mutation quantum.4. D-ribose fermentation conditions were studied, and the optional D-ribose fermentation conditions were 240r/min, 35ml broth volume in 500ml tri-angle bottle and 15% inoculation volume. In media optimization process, uniform design and multi-method joining fractional factorial design and response surface optimization design were adopted respectively, and the experimental results showed that multi-method is better than uniform design on the condition that operation conditions cannot be controlled strictly. The optional media is obtained by using multi-method: glucose 150g/l, corn steep liquor 134 g/1, (NH4)2SO4 7g/l, MnSO4 0.05g/l, CaCO3 15g/l, and the corresponding D-ribose yield is 44.1g/1.5. Based on the optimal fermentation media, ratable bottle fermentation dynamics model was constructed. The magnifying fermentation on reactor was processed, and its dynamics model was constructed.So, in this paper, the theoretical and practical basement of increasing D-ribose fermentation further is provided by studying analytical method of parameters and studying fermentation process.