| Abstract: |
One hundred and fifty random samples of market ( 50 samples),pasteurized milk (50 samples) and farm milk (50 samples) were collectedfrom different localities In Sharkia Govemorate to determine theincidence of psychrotrophic and lipolytic psychrotrophic bacteria, using standard plate count agar and victoria blue butter fat agar.The results obtained show that all raw milk samples containedpsychrotrophs while pasteurized milk contained 20% psychrotrophicbacteria the incidence of iipolytic psychrotrophic bacteria were (35) 70%,(6) 12?1o and 26(52%) in market milk, pasteurized milk and farm milk,respectively. The mean values of psychrotrophic bacterial counts inmarket milk, pasteurized milk and fann milk were 8x10° ± 1.6 x 10°,2 X10:1 ± 4.5 x 102, and 6.25 x 104 ± 1.6 x 104, respectively.while the mean values of lipolytic psychrotrophic bacterial countIII market milk, pasteurized milk and farm milk were lA x 106 ± 3 x 105,7 x 10 ± 3 x 10, and 3.5 x 104 ± 1.5x104, respectively.The frequency distribution of lipolytic psychrotrophic bacteriaobtained from market milk, 23 were pseudomonas spp., 9 Aeromonasspp., 12 Staphylococcus spp., 7 Micrococcus spp., 8 Bacillus spp., 9Acinetobacter spp., 5 Streptococcus spp., 3 Alcaligenes spp., 9Enterobacter spp. and 4 Serratia spp.
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