| 摘要 |
1,157,213. Lactic acid and salts thereof. RHONE-POULENC S.A. 16 Jan., 1967 [17 Jan., 1966], No. 2255/67. Heading C2C. D-Lactic acid or salts thereof are obtained by the fermentation of a nutrient medium comprising at least one sugar and a source of assimilable nitrogen characterized by the addition to the nutrient medium of at least one inhibitor of parasitic organisms and the use of a microorganism insensitive to the inhibitor and capable of producing D-lactic acid from a sugar, and separation of the resultant D-lactic acid as such or in the form of a salt. The inhibitor may be a mineral salt, an organic substance having an antiseptic or antifungal action, an antibiotic, e.g. a penicillin, streptomycin, neomycin, kanamycin, chloramphenicol, a tetracycline, novobiocin, spiramycin or polymyxin, a copper or zinc salt, formaldehyde, a quaternary ammonium derivative or a, sulphonamide. The microorganism producing D-lactic acid is suitably accustomed to the inhibitor of parasitic microorganisms by preliminary culture in the presence of increasing concentrations of the inhibitor and the fermentation is suitably effected at a temperature not exceeding 50‹ C. The source of sugar may be molasses, the assimilable nitrogen source may be corn-steep and the initial fermentation medium is preferably at least partially sterilized. The D-lactic acid producing micro-organism employed may be Lactobacillus leichmannii, Lactobacillus lactis or Lactobacillus caucasicus. |
