An aureomycin rose bengal agar for enumeration of yeast and mold in cottage cheese

An aureomycin rose Bengal agar for the enumeration of yeast and mold in cottage cheese was studied. When mold isolate, yeast isolate, and yeast and mold on cottage cheese counts were compared, preliminary results indicated two of seven levels of aureomycin and rose bengal in peptone dextrose agar gave comparable or higher counts than potato dextrose agar. The two levels of aureomycin and rose bengal in peptone dextrose agar were given more detailed study. The first level contained 20 parts per million aureomycin and 20 parts per million rose bengal in peptone dextrose agar. The results of mold isolate, yeast isolate, and yeast and mold on cottage cheese counts with this agar were compared to counts on potato dextrose agar. The second level contained 30 parts per million aureomycin and 10 parts per million rose bengal in peptone dextrose agar. The mold counts with this level were compared with mold counts on the other aureomycin rose bengal agar and potato dextrose agar. The growth of five bacterial organisms on the 20 parts per million aureomycin and 20 parts per million rose bengal in peptone dextrose agar was studied.

The results of the study show no statistical significant difference for yeast isolate, mold isolate, and yeast and mold on cottage cheese counts between the 20 parts per million aureomycin and 20 parts per million rose bengal in peptone dextrose agar and potato dextrose agar. Also, there was no statistical significant difference between the two levels of aureomycin and rose bengal in peptone dextrose agar and potato dextrose agar for mold counts. Tests for bacterial growth indicate there was no bacterial growth on aureomycin rose bengal agar.