Bio-production Of Cis-3,5-dihydroxycyclohexa-1,2-diene By Recombinant Escherichia Coli JM109 And Synthesis Of Poly(paraphenylene)

Cis-3, 5-dihydroxycyclohexa-1, 2-diene (DHCD) is the monomer for synthesis of poly-para-phenylene which is a material with excellent electrical properties. It can be used as a valuable chiral monomer and intermediates in the pharmaceutical, electronics, aerospace and fine chemical industries as well. This paper mainly focused on the process of fermentation of DHCD and the extracting methods from the broth. Besides, Poly (paraphenylene) (PPP) was synthesized and its relative qualities were investigated. On the aspect of fermentation, the concentration of initial culture media was found out through orthogonal analysis. The influence of IPTG and ways of feeding benzene were also investigated. An optical process was found for the fermentation. The initial temperature was 37oC. Glucose was fed continuously for prohibiting the accumulation of acetate acid. Once the reaction reached mid-exponential phase, the temperature was reduced to 30oC, and 0.5mM IPTG was added to induce toluene dioxygenase (TDO) activities. Two hours later the mixture of paraffin liquid and benzene (3:1) were fed continuously by peristaltic pump. As a result, the yield of 45 g/l DHCD was achieved. According to the instability of DHCD in the acidic condition under the high temperature and nearly free solvable quality in the water, the efficiency of current process of extracting DHCD by solvent extraction was really low. The method of extracting DHCD from the fermentation broth with macroporous resin was investigated systematically in the second part of this paper. As a better result, the polar NKA-II resin was chosen as the absorbent to extract DHCD, with the sampling speed of 1.2 ml/min and methanol as the washing solvent. The extraction rate reached to 82.2%, much better than the existing extraction technique with methylene chloride as a solvent. In the last part of the paper, some PPP powder, whose Mn is 20,000, is synthesized from DHCD under a series of reactions. Its chemical functional construction was confirmed by FT-IR and FT-raman spectrum. Then the PPP was doped with ferric trichloride in nitryl methane as a solvent, under the temperature of 60oC. The doped products were conductive with 0.1 S/m of conductivity. In addition, the pre-polymers had been processed as unwoven cloth by the method of electronic spinning.