FLEISCHWIRTSCHAFT, cilt.87, sa.12, ss.106-110, 2007 (SCI-Expanded)
Totally, 53 samples of raw minced meat were collected from markets in Ankara. The mean counts of total aerobic mesophilic bacteria, psychrotrophic bacteria, Enterobacteriaceae, psychrotrophic Enterobacteriaceae were 1.3x10(5), 4.1x10(4), 6.8x10(3), 3.6x10(3) cfu/g, respectively. The isolates of Pseudomonas and the other Gram-negative psychrotrophic bacteria were Pseudomonas fluorescens biotype I in 12 (22.6%), P. fluorescens biotype II in 3 (5.7%), P. putida in 14 (26.4%), P. acidovorans in 1 (1.9%), Acinetobacter calcoaceticus anitratum in 5 (9.4%), A. calcoaceticus lwoffii in 4 (7.5%), Alcaligenes denitrificans in 6 (11.3 %) and A. faecalis in 1 (1.9 %) of the samples. R fluorescens biotype I and II, and R putida isolates showed proteolytic activity. while P. acidovorans did not show proteolytic activity. Pseudomonas spp, Acinetobacter spp and Alcaligenes spp showed highest resistance to amoxicillin, ampicillin, cephalothin, cephazolin, (between 73.3% and 100%). The results suggest that psychrotrophic Gram-negative bacteria such as Pseudomonas species, especially P. fluorescens, pose a significant spoilage problem in raw minced meat refrigerate due to secretion of hydrolytic enzymes, especially proteases.