A-1 Medium is a granulated dehydrated culture medium used to detect fecal coliforms in non-potable and wastewater. Peptone from casein, lactose, and salicin are nutrients and guarantee good growth of microorganisms. Sodium chloride provides osmotic balance. Triton™ X 100 is incorporated as a detergent.

Appearance (clearness): clear

Appearance (colour): yellowish to yellow

pH-value (25 °C): 6.7 - 7.1

Growth (Escherichia coli ATCC 25922 (WDCM 00013)): good to very good

Growth (Escherichia coli ATCC 8739 (WDCM 00012)): good to very good

Growth (Enterobacter aerogenes ATCC 13048): none to fair

Growth (Enterococcus faecalis ATCC 19433 (WDCM 00009)): none to fair

Growth (Bacillus subtilis ATCC 6633 (WDCM 00003)): none

Growth (Aeromonas hydrophila ATCC 7966 (WDCM 00063)): none

Gas (Escherichia coli ATCC 25922 (WDCM 00013)): +

Gas (Escherichia coli ATCC 8739 (WDCM 00012)): +

Gas (Enterobacter aerogenes ATCC 13048): none or poor

Gas (Enterococcus faecalis ATCC 19433 (WDCM 00009)): -

Gas (Bacillus subtilis ATCC 6633 (WDCM 00003)): -

Gas (Aeromonas hydrophila ATCC 7966 (WDCM 00063)): -

Incubation: 3 hrs.; 35 °C; aerobic. 19 - 23 hrs.; 44.5 °C.