Dextro-3-hydroxybutyric acid prepn. by oxidative fermentation - using microorganism strain mutant incapable of storing poly-3-hydroxybutyric acid

摘要

acid, (I), is prepd. by (i) oxidative fermentation with poly-3-hydroxybutanoic acid-forming microorganism species mutants in an aq. substrate contg. (a) NH4-, Mg-, Ca-, Fe-, phosphate-, sulphate-, and trace element ions and either (b-I) contg. one or more organic O-contg. cpds. having C-C covalent bonds, 3-6C and 2-6 functional O-contg. gps. or (b-2) traversed by a CO2-H2-O2 gas mixt. stream, at up to 45 deg. C and weakly acid to weakly alkaline pH, and (ii) separating (I) from the culture liquor. Novelty consists in cultivating mutants which have lost the poly-3-hydroxybutanoic acid-prodn. capacity and which accumulate and secrete (I) in cells but are unable to utilise the secreted (I). A submerged culture is used, with growth-limiting reduction of NH4-, Mg-, sulphate-, phosphate- and Fe concns. and low, growth-limiting O2 partial pressure enabling breathing rates of 10-12% of max. achievable values of cell culture, in the presence of excess C-source. (I) is used for biochemical organic synthesis, physiological pharmaceutical and medicinal purposes.