DE2920764

Glycerol dehydrogenase enzymes having exeptionally good thermal stability are produced by culturing novel strains of Bacillus stearothermophilus. Procedures for deriving and identifying suitable strains are described. The strains are grown in conventional culture media, preferably containing 0.05 to 4.0%, especially 0.1 to 1.0%, by weight of glycerol or a glycerol analogue at 40 DEG -65 DEG C. and pH 5 to 8. The enzyme is isolated by conventional cell disruption and separation techniques, and typically has a molcular weight of 240,000+/-30,000, composed of four similar sub-units, and a specific activity of greater than 5 Units per mg protein at 30 DEG C. by the modified assay described. They may be stored as aqueous solutions or a freeze dried solids. The enzymes may be used for assay of serum triglycerides by conventional assay methods, but preferably by the nictotinamide adenine dinucleotide spectrophotometric assay at a pH of 7 to 8.8. The pH is preferably controlled by an amine, especially triethanolamine/HCl, buffer.