| 摘要 |
1535632 Producing poly-(3-hydroxybutyric acid) from bacteria AGROFERM AG 4 Aug 1977 [6 Aug 1976] 32783/77 Heading C3R [Also in Division C6] The invention is directed to a method of obtaining new bacterial strains (see Division C6) which are capable of producing microbiologically on a large scale poly-(D-3-hydroxybutyric acid) from cheap, abundant raw materials. The poly - (D - 3 - hydroxybutyric acid) obtained may be processed using conventional techniques to manufacture structures and moulded bodies such as threads, fibres and films which although resistant to acids, alkalis, light, air and most organic solvents, are biodegradable, e.g. in soil. The selected mutant strain is cultivated in the presence of the appropriate assimilable carbon source, such as glucose, fructose, sucrose, molasses, methanol, ethanol, glycerin, carbon dioxide and neutralized spent lye from caprolactam synthesis of specified composition, an assimilable nitrogen source material and trace elements, preferably in submerged culture, and the poly(D-3-hydroxybutyric acid) thus produced is isolated from the culture medium by extraction with polar or lipophilic solvents, e.g. ethanol, ethylene carbonate or propylene carbonate. The properties of the solvent largely determine the molecular weight of the poly-acid extracted. Molecular weights above 1,000,000 may be obtained by extracting with, e.g. propylene carbonate at 120‹ C. for 1-5 minutes. The extracted poly- (D-3-hydroxy butyric acid) may be subjected to intermolecular esterification to give poly-acid having an increased molecular weight. |
