Abstract: The object of the invention is a microbe culture medium which can be activated with a liquid sample or water. Covalently crosslinked cellulose ethers are used as a gelling agent. The gel into which nutrients have been mixed is dried on a water-impermeable support. The culture medium according to the invention may be utilized for detecting bacteria and fungi both in the hygiene control of industry and in medical diagnostics. The same method principle may be used within different sensitivity ranges as the absorption capacity of the gel may be regulated according to the hydrophilicity of cellulose ethers.

Abstract: The invention comprises a culture medium and method for distinguishing bacteria of Salmonella species from other gram-negative bacteria, especially those belonging to the family Enterobacteriaceae. It is based on the ability of salmonellae to utilize melibiose, mannitol, and sorbitol and convert them into acids, together with a chromogenic substrate used for identifying .beta.-galactosidase. Other bacteria of the family Enterobacteriaceae, most of which are .beta.-galactosidase-positive, appear as brown, blue, or green colonies, depending on the chromogenic substrate used. Apart from Salmonella species, other .beta.-galactosidase-negative bacteria, such as Proteus species, appear as colorless colonies. Salmonellae can be identified directly on the culture medium after incubation, by their characteristic bright red color.