Detachment of Pseudomonas fluorescens P26 from Beef Rinsed in Salt and Acid Solutions

Abstract

The purpose of this study was to test the hypothesis that numbers of bacteria detached from meat could be increased by modification of the ionic environment surrounding both the meat and bacterial surfaces. Of five 0.1 M chloride salt solutions that were used to rinse cells of Pseudomonas fluorescens P26 from meat, KCl removed the highest average number of cells. These numbers were significantly greater than those for NH4Cl and MgCl2. Compared with water, the solution of 0.1 M KCl rinsed three times as many bacteria from cubes of inoculated meat shaken in solution for 1 min and there were one-half as many bacteria recovered from meat rinsed with KCl as from meat rinsed with water. The latter difference was significant, and we conclude that KCl assisted in detachment of the pseudomonads. However, no significant effect of 0.1 M KCl was observed when it was added to water that had been buffered to pH 4 and 5 with citrate-phosphate buffer. Instead, the buffered rinse caused a large loss in viability of the pseudomonads. This large loss in viability may have over-shadowed the smaller effect of KCl.