Abstract: A process for the selective enzymatic hydroxylation of aldehydes and ketones using chiral anchor-protective groups.

Abstract: Hypochlorite digestion of bacterial biomass to recover intracellular poly-.beta.-hydroxylalkanoic acid (PHA) has not been used on a large scale since it has been widely reported to severely degrade the polymer. The process of the invention proposes to optimize the initial biomass concentration, the digestion time and pH of the hypochlorite solution to minimize degradation. Consequently, PHA of up to 95% purity with an average molecular weight of 600,000 can be recovered from biomass initially containing PHA having a molecular weight of 1,200,000. By incorporating a pretreatment step with an anionic surfactant solution, PHA of 99% purity with a molecular weight of 1.20.times.10.sup.6 was obtained from biomass containing 57% PHA by weight with an initial molecular weight of 1.25.times.10.sup.6.

Abstract: The present invention relates to a process for the biotechnological preparation of poly-D-(-)-3-hydroxybutyric acid, herein referred to as PHB, which comprises culturing a microorganism that is a strain of Alcaligenes latus or a PHB-producing mutant thereof with unrestricted supply of nutrients, under unlimited growth conditions in the temperature range from 36.degree. to 42.degree. C. at a dissolved oxygen content of 25 to 50% of the saturation value for air and a pH value of 6.0 to 7.5. The PHB is then isolated in the customary manner from the biomass thereby obtained.

Abstract: 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.