A microorganism detection medium, said detection being based on showing the presence of a microbial enzyme activity chosen from esterase and/or osidase and/or peptidase and/or sulfatase and/or phosphatase activities of microorganisms, preferably said microbial enzyme activity being an esterase activity, said medium comprising: at least one chromogenic and/or fluorogenic substrate specific to the enzyme activity sought, preferably specific to an esterase activity, at least one alkyl(thio)glycoside, at least one solvent (S).