Studies On Metabolic Regulation For Polyhydroxyalkanoate And Downstream Process By Sinorhizobium Fredii

Polyhydroxyalkanoates(PHA) are polymers that are produced by many bacteria and accumulated as intracellular granules. It not only has the characteristic of petrochemical plastics but also has the biodegradability, biocompatility. These biologic polymers are new kinds of environment-friendly material that provide a novel way to resolve White Pollution and can be used as scaffold material in medical tissue engineering. Synthesis of the bioplastic poly (3-Hydroxybutyrate-co-3-Hydroxyhexanoate)[p(HBHH)],Poly(3-Hydroxybutyrate-co-Hydroxyoctanoate) [p(HBHO)] by a Sinorhizobium fredii strain using sodium decanoate and sodium dodecanoate as auxiliary carbon source,with Glucose as the primary carbon source. Due to the physical and biologic property of P(HB-HH) and P(HB-HO),they provide a wide prospect of application in medical tissue engineering.In this paper, principium process was established through the research on correlative parameter of metabolic regulation by two-stage fed-batch fermentation process in a 100-L fermentor system. The maximum P (HB-HH) production could be 10.34 g/L with a monomer ration of 61%(w/w) 3-HB and 30% (w/w) 3-HH. The molecular weight (M_w) of the P (HB-HO) was measured as 1.37×10~5Da by a viscosity method. The maximum P(HB-HO) production could be 12.74g/L with a monomer ration...