A method for screening diacetyl and acetoin‐producing bacteria on agar plates

A simple method for screening bacteria for diacetyl and acetoin production was developed. This method is based on the ability of diacetyl and acetoin to form a red insoluble complex with α‐naphthol in the presence of creatine. Addition of carboxymethyl‐cellulose containing calcium citrate in the medium allowed discrimination between citrate utilizing and non‐utilizing bacteria.