Factors affecting aerobic colony counts for bottled water

摘要

The Canadian Official Method MFO-15 for aerobic colony counts of bottled waters and ice requires pour plating with plate count agar (PCA) tempered to 40-45 degrees C and incubating 48 h at 35 degrees C. The performance of hydrophobic grid membrane filters (HGMF), counted by computerized counter after 48 h incubation on various media, was compared against MFO-15 for 31 water samples collected across Canada, and potential sources of error in MFO-15 were investigated.