A thin film culture device for detecting aerobic bacteria in a sample is provided. The culture device comprises a self-supporting substrate sheet having a first major surface and a second major surface; a cover sheet attached to the substrate sheet, a sample-receiving zone disposed between the substrate sheet and the cover sheet, a first layer comprising a substantially dry, cold-water-soluble first hydrogel-forming composition adhered to a portion of the sample-receiving zone; and a plurality of indicator agents disposed in at least one layer adhered to the substrate sheet or the cover sheet. The plurality of indicator agents comprises three indicator agents for detecting distinct glycosidase enzyme activities, an indicator agent for detecting an alkyl esterase enzyme activity, an indicator agent for detecting a phosphatase enzyme activity, and a redox indicator. A method of using the culture device is also provided.