Spoilage potential of pseudomonas spp. isolated from domiati cheese

الملخص EN

In this study, 80 samples of popular Egyptian raw milk cheese, Domiati cheese, were examined for the incidence and characteristics of Pseudomonas spp.

using traditional and molecular techniques.

70 of examined cheese samples (87.5%) were contaminated with Pseudomonas spp.

Mean Pseudomonas spp.

counts was 4.59 ± 0.35 log cfu/g, whereas mean proteolytic Pseudomonas spp.

counts was 3.65 ± 0.14 log cfu/g.

Screening of the eighty isolated strains by species-specific PCR revealed high incidence of P.fluorescens (45%).

97.5%, 87.5% and 73.7% of isolated strains showed protease, lipase and lecithinase activities, respectively.

Interestingly, 75% of the P.

fluorescens strains were positive for all enzyme activities.

The alkaline protease (apr) gene was detected in 41.25% (33/80) of isolates and proteolytic activity was observed in all strains carried this gene.

72.5% (58/80) of isolated strains were psychrotrophic.

In conclusion, this study provides information about the spoilage potential of Pseudomonas spp.

in Domiattie cheese and merely underline the importance of strict hygiene measures in preparation of Domiati cheese in Egypt.