Process for the biotechnological preparation of poly-d-(-)-3-hydroxybutyric acid

摘要

The present invention relates to a process for the biotechnological preparation of poly-D-(-)-3-hydroxybutyric acid (PHB) which comprises continuously culturing a microorganism that is a strain of Alcaligenes latus or a PHB-producing mutant thereof, in two separate successive fermentation stages with unrestricted supply of nutrients. The PHB-containing microorganism population cultured in the first stage with a dissolved oxygen content of 25 to 50% of the saturation value for air is then continuously transferred into a second fermentation stage in which the culture is continued at a dissolved oxygen content of 8-15% of the saturation value of air. The PHB is extracted in the usual manner from the biomass thereby obtained.