Abstract: The present invention provides a process for obtaining glucose dehydrogenase by culturing a micro-organism in an appropriate nutrient medium and obtaining the enzyme from the cell mass or from the culture medium, wherein the micro-organism cultured is Bacillus cereus DSM 1644. The nutrient medium used contains a carbon source which consists predominantly or solely of glycerol.

Abstract: A novel peroxidase for reduced nicotinamide-adenine-dinucleotide is provided which peroxidase oxidizes reduced nicotinamide-adenine-dinucleotide with hydrogen peroxide to give nicotinamide-adenine-dinucleotide and water and is characterized by a Michaelis constant K.sub.Mto hydrogen peroxide of 2.8.times.10.sup.-5 M andto reduced nicotinamide-adenine-dinucleotide of 1.7.times.10.sup.-5 M,measured at 25.degree. C. in 0.2M tris buffer of pH 6.0, containing 0.1M potassium acetate. The peroxidase can be prepared by liberating the enzyme from Streptococcus faecalis ATCC 8043 by digestion or by treatment with a surface-active agent and isolating same from the enzyme solution obtained. Hydrogen peroxide is determined in a simple reaction or in a coupled reaction with a specific oxidase by contacting the said peroxidase with the H.sub.2 O.sub.2 producing reaction mixture at a pH of from 6.0 to 9.0 and measuring the change of extinction as a measure of H.sub.2 O.sub.

Abstract: In a process for the determination of total or bound cholesterol by liberating any bound cholesterol using cholesterol esterase and simultaneously or subsequently determining the liberated cholesterol and any initially free cholesterol with a cholesterol reacting enzyme, the improvement comprising using as the cholesterol reacting enzyme an NAD or NADP-dependent cholesterol dehydrogenase obtained from an anaerobic microorganism, e.g., Eubacterium sp. ATCC 21408, or from mammalian tissue, e.g., liver.