The incidence of proteolytic pseudomonas species associated with ground beef with regards to their spoilage effect

Abstract EN

Fifty fresh samples of ground beef were randomly purchased from butchers shops from Port-Said city.

The samples were examined for enumeration of the total psychotrophic and proteolytic Pseudomonas 1 counts with studying the proteolytic activity of the isolated strains.

The incidence of positive samples for total psychrotrophic and proteolytic J Pseudomonas were 100 % (n = 50) for each, while the mean values of the total psychrotrophic and proteolytic Pseudomonas counts were 7.2 X 104 ± 1.7 X 104 and 1.3 X 104 ± 1.8 X 103 CFU / g of ground beef respectively.: Most of total psychrotrophic and proteolytic Pseudomonas counts ranged from 103 to <106 CFU/g of ground beef.

139 psychrotrophic Pseudomonas strains isolated from the examined samples were identified as Pseudomonas fragi (Cluster II), Pseudomonas lundensis (Cluster IV), Pseudomonas fluorescens (Cluster II) and Pseudomonas putida (Cluster II) with an incidence of 59 (42.45 %), 33 (23.74 %), 25 (17.99 %) and 22 (15.83 %) respectively while the 99 proteolytic strains constituted 50 (50.51 %), 29 (29.29 %), 20 (20.20 %) and 0.0 (0.00 %) for the aforesaid strains respectively.

The proteolytic activity of the isolates in the examined samples were 5.50 ± 0.700, 1.60 ± 0.361 and 3.69 ± 0.855 for Pseudomonas fragi (Cluster II), Pseudomonas lundensis (Cluster IV) and Pseudomonas fluorescens (Cluster II) while that of Pseudomonas putida (Cluster II) could not be detected.

The public health and economic significance of isolated strains were discussed.