Abstract: Copolymers of poly(beta-hydroxybutyric acid) and poly (beta-hydroxyvaleric acid) are produced by culturing alcohol-utilizing strains of Alcaligenes eutrophus on a carbon source including primary alcohols having an odd number of carbon atoms such as propan-1-ol.

Abstract: The recoverable yield of recombinant human albumin in the fermentation of genetically engineered yeast that expresses the albumin and secretes it into the culture medium is increased by the addition of a stabilizing agent comprising a polyoxyalkylene compound, for example, polypropylene glycol or a polyoxypropylene/polyoxyethylene copolymer. The presence of these compounds in concentrations of from about 0.5 to 10 g per liter, preferably 1 to 5 g per liter, of fermentation broth prevents the degradation of the rHA produced under intensive fermentation conditions thereby raising the effective yield.

Abstract: High molecular weight copolymers containing 3-hydroxybutyrate residue, i.e. units of the formula--O.CH(CH.sub.3).CH.sub.2.CO--and up to 50 mole % of residues of other hydroxy acids, viz units of the formula--O.CR.sup.1 R.sup.2.(CR.sup.3 R.sup.4).sub.n.CO--where n is 0 or an integer and, if n=1 and R.sup.2, R.sup.3, and R.sup.4 =H, R.sup.1 is not methyl.The copolymers are made microbiologically: for part of the cultivation the micro-organism is under conditions such that polymer is accumulated, e.g. by limitation of a nutrient, e.g. nitrogen source, required for growth but not polyester accumulation. For at least part of this period of polymer accumulation the substrate is an acid or a derivative thereof that gives the comonomer units. Proprionic acid, which gives polymers where n=1, R.sup.2 =R.sup.3 =R.sup.4 =H and R.sup.1 =C.sub.2 H.sub.5, is the preferred acid.