SURVIVAL OF SALMONELLA-TYPHIMURIUM IN SOIL AND LIQUID MICROCOSMS AMENDED WITH CLINOPTILOLITE COMPOUNDS

The objectives of this study were to screen the effect of different cl inoptilolite compounds on S. typhimurium survival and to compare the m ost effective compounds as amendments using agricultural soil and aque ous microcosm conditions. These microcosms were inoculated with the ba cterial culture and at periodic intervals (over 12-30 days) viable Sal monella populations were enumerated using selective media. In screenin g studies Salmonella populations were found to be lower from the small er mesh clinoptilolite compounds than from wood-chip sources or larger mesh clinoptilolite compounds at the end of 14 days. However the resp onse was highly correlated with the change in moisture content. In soi l microcosm studies where moisture content was kept constant, there wa s an overall reduction of about 4 log units bur there was no significa nt difference between the unamended control and the treatments. When s maller mesh clinoptilolites were evaluated in phosphate saline buffer there was a significantly lower (P<0.05) number of viable S. typhimuri um than in the unamended treatments. However, when the clinoptilolite compounds were sterilized prior to use, if was observed that the bacte rial populations were protected from viability loss when compared with the unamended control.