Inoculate five characteristic colonies, if available, into tubes of BGLB. Incubate the tubes at 30 OC for 48h. Consider colonies producing gas in the Durham tubes as coliforms.

• 如果可能，转接5个典型菌落到BGLB管中，30OC培养48小时。导管内产气的菌落为大肠菌群阳性。