| Catechol with high deoxidize ability is an important chemical intermedia. Catechol is predominantly used for synthesizing antioxidant, tan-reagent and flavor, etc. Moreover, it is vastly applied to produce pesticide and to synthesize medicine. Up to now, two traditional methods include both chemosynthesis and extraction from the natural plants are avarible for producing catechol. Due to the limitation of those methods, particularly with the rapid growth of utilization catechol around the world recently and the stress from green chemistry, more attention has been paied to the new ways to produce catechol, for example,a good idea is to produce catechol by micro- organisms under the regular air pressure and temperature.For biosynthesis of catechol by microorganisms in large scale, it is necessary to understand the following four kay questions: 1) An excellant microorganism strain should be isolated and chararctered. 2)A good method could be employed for fast determination of catechol and its varials. 3) The fermentation condition with the free cells should be optimationed. 4) The immobilized cells should be used in large scale. In this thesis, we reported some research results to answer these questions.When oxygen is the only oxidant, the reaction of the standard solution of catechol or the solution of catechol with multihydroxy compound blended and 4—AAP (100mg4-aminoantipyrine,2ml1mol/L NaOH and 10ml20%Na2CO3were dissolved to 100ml) was carried out, the result of absorbing on 510nm wavelength showed that only catechol had absorbing peak. Total 228 microorganisms were isolated from several soil samples based on benzoate as a sole carbon source. Among the microorganism obtained, four strains produced and accumulated catechol as well as the strain A9,B5,G3,K12 were the better strains.Among them, the strain B5 was the best one. According to its morphological and physio-biochemical characters strain B5 was belonged to Pseudomonas sp..The Pseudomonas sp.B5 was as lab strain, the results showed that the best fermentation mediums was sodium benzoate 6mg/ml,KH2PO4.7H2O 7.5 mg/ml,Na2HPO4.12H2O 3.5mg/ml,NaCl 0.5 mg/ml,(NH4)2SO4 0.4 mg/ml,yeast –extract 0.5 mg/ml,PH6.0,MgSO4.7H2O 1 mg/ml,FeSO4.7 H2O,CaCl2.2H2O,CuSO4.5H2O,ZnCl2 individed was 1mg/l,glycerol 1.1 mg/ml. The flask cultures were incubated at 29℃ for 24h under the condition of pH6.0 , 150rpm. The yield of catechol could reach 2.4mg/ml, the conversion rate of sodium benzoate was 52.2% on a molar basisIn this report we studied on prodiction of catechol with Sodium Benzoate by the immobilized cells of microorganism sp.B5. Resulted from comparison of three immobilization materials including gelatin, calcium alginate and chitosan as well as with three different concentration on each material, a good immobilization condition including 15g/L chitoson, 50mmol/lcalcium alginate, 0.20%(v/v) glutaraldehyde, at 35℃ for 8h had been establized. The average diameter of immobilized beads was about 2.5mm. On the medium which contain sodium benzoate (5mg/ml) and glycerol(1.2mg/ml), it could be fermented continuously 14 times and the average output of catechol was 1.5mg/ml after 32h at 30℃, the conversion rate of benzoate was 34.3% on a molar basis. |
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