Abstract: Cholesterol oxidase which oxidizes cholesterol with oxygen to give cholestenone and hydrogen peroxide, is prepared by culturing Nocardia erthropolis ATCC 17895, Nocardia erthropolis ATCC 4277, Nocardia formica ATCC 14811 or Proactinomyce erythropolis NCIB 9158 first on a peptone-containing mineral salt medium and thereafter on at least one sterol compound as the sole source of carbon, and then isolating the cholesterol oxidase formed from the cultured micro-organism, wherein said sterol compound is of the formula ##STR1## in which R.sub.1 and R.sub.2 are hydrogen or together represent a double bond,R.sub.3 and R.sub.4 are hydrogen or together represent a double bond, andR.sub.5 is hydrogen or alkyl containing up to 3 carbon atoms.

Abstract: Carrier-bound proteins are prepared by reacting a protein in aqueous solution with a coupling compound having at least one group capable of acylating or alkylating proteins and at least one additional group capable of producing a bond with a carrier material, and reacting the resulting product with a carrier material, optionally forming the carrier material in situ by polymerization of a monomer or monomer mixture in the presence of said product.

Abstract: Glucose is converted into gluconic acid by oxidation with oxygen in aqueous solution, by a process comprising passing a glucose containing aqueous solution over a catalyst which contains glucose oxidase and catalase, bound to an appropriate carrier, in immediate proximity to one another. The process avoids the disadvantage of previous catalytic processes depending on catalysts which rapidly lose their activity and is adapted to large-scale operation.