| 摘要 |
PURPOSE:To produce a biopolymer for producing a biodegradable plastics in high efficiency by culturing a microbial strain in a medium containing a sugar under heterotrophic condition and fermenting the cultured microbial cells in a reactor in a stream of a mixed gas containing hydrogen, oxygen and carbon dioxide gas and having a low oxygen concentration to be free of explosion hazard. CONSTITUTION:A biopolymer for the production of a biodegradable plastics such as poly-beta- hydroxybutyrate(PHB) is fermentatively produced from carbon dioxide by culturing a bacterial strain under autotrophic condition according to the following procedures. A medium (a) containing a sugar as a main raw material is supplied to a 1st tank 1 and a bacterial strain (e.g. Alcaligenes eutrophus ATCC 17697) is cultured under heterotrophic condition. The proliferated bacterial cells are transferred through a broth extraction port (b) to a reactor 2 supplied with a mixed gas composed of hydrogen, oxygen and carbon dioxide gas and having a sufficiently low oxygen concentration not to cause the explosion hazard from a gas chamber 4 through a gas feed (d). The cells are subjected to fermentative cultivation to accumulate a large amount of biopolymer such as PHB in the cell and taken out of the reactor through a discharging port (c) to obtain a biopolymer for the production of biodegradable plastics. |
