Life span of listeria monocytogenes in white cheese during 90 days of lipening

In this research, white cheese which was ripened in 2 different brines(%13 and %17) was studied. During cheese production, 2 different levelof Listeria monocytogenes were inoculated into the milk. The life spanof L. monocytogenes was investigated and the effects of inoculationlevels and salt concentrations were examined. In all samples, in allbrines, L. monocytogenes survived for 75 days. No L. monocytogenesbacteria were able to live up to 90 days. The brines were alsoinvestigated in realesing to L. monocytogenes levels. L.monocytogenes survived for 75 days in brine which had % 13 saltconcentration, but in brine with % 17 salt concentration the bacteriasurvived for 60 days.Also total mesophyl, coliform, lactic acid bacteria and yeast countswere made. In 0., 7., 15., 30., 45., 60., 75. and 90th days Gram negativeand lactic acid bacteria identifications were made. Biochemicalcharacterization of the strains were conducted with bioMerieux API 50CHL for Lactic Acid bacteria. The distribution of Total lactic acidbacteria in 90 days is as follows : 43 % Lactococcus lactis subsp.lactis, 16 % Enterococcus faecalis, 8 % Lactobacillus plantarum, 6 %Lactobacillus paracasei subsp. paracasei, , 3 % Streptococcus avium,5 % Enterococcus hirae, 4 % Pediococcus pentocaseus , 4 %Streptococcus casseliflavus, 9 % Enterococcus faecium and 2 %Lactococcus lactis subsp. cremorisBiochemical characterisation of the strains were conducted with API 20E for Gram negative bacteria also. The distribution of Gram negativebacteria in white cheeses in 90 days is as follows : 32 %Enterobacter( 23 % E. sakasaki ve 9 % E. cloacea) , 18 % Serratia ( 7 % S.liquifaciens and 11% S. fonticola), 9 % Acinetobacter baumania, 18 %Citrobacter ( 6% Citrobacter freundii, 10 % Citrobacter amalinoticus)6 % Xanthomonas maltophilia, 2 % Pasteurella multicoda, 5 %Klebsiella (1 % Klebsiella pneumoniae, 4 % Klebsiella ornithinolytica),2 % Salmonella choleraesuis, 4 % Aeromonas salmonicida, 5 %Escherichia coli, 1 % Chryeomonas luteola , % 4 Cedecea davisae.Chemical analyses were conducted in the same days as identifications.pH, % lactic acid, salt amount, dry matter and salt in dry mater resultswere obtained. During 90 days pH, salt amount and salt in dry matterincreased, but % titration acid and dry matter decreased