A medium detecting β-glucuronidase for the simultaneous membrane filtration enumeration of Escherichia coli and coliforms from drinking water

A medium for the single membrane enumeration of Escherichia coli and coliforms from potable water was developed by the modification of the standard UK membrane filtration medium. The medium, membrane-Lactose Glucuronide Agar (m-LGA), employs a chromogenic substrate for the detection of β-glucuronidase activity and sodium pyruvate to enhance recovery of chlorine-stressed coliforms. Escherichia coli identification was significantly improved on m-LGA with 98.6% of presumptive isolates confirming. Recovery of coliforms from drinking water samples was also significantly improved.