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Effect of NaCl on Heat Tolerance of Enterococcus faecium and Enterococcus faecalis

Mushtaq Ahmad , David G. Smith and Shahid Mahboob

The effect of NaCl on heat tolerance of Enterococcus faecium BAR1 and Enterococcus faecalis MI2 was determined at 55, 60 and 62.5oC for half an hour. Cells of both isolates were grown in Brain Heart Infusion broth containing 6.5% NaCl. Exponential phase cells were used as inoculants. Cells of both isolates were found resistant to heat treatment as compared with cells grown in BHI broth without presence of salt. The decimal reduction times (D-values) were determined by 1 log fall in viable count. Both isolates showed similar results at 55oC but at 60oC E. faecalis MI2 showed higher D-value than E. faecium BAR1. At 62.5oC E. Faecium BAR1 was found more tolerant to heat treatment than E. faecalis MI2. Experiments showed that the presence of salt in the growth medium induces more heat tolerance in enterococci than the cells grown in normal medium.

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  How to cite this article:

Mushtaq Ahmad , David G. Smith and Shahid Mahboob , 2002. Effect of NaCl on Heat Tolerance of Enterococcus faecium and Enterococcus faecalis . Journal of Biological Sciences, 2: 483-484.

DOI: 10.3923/jbs.2002.483.484


Bell, R.G. and K.M. DeLacy, 1984. Heat injury and recovery of Streptococcus faecium associated with souring of chub-packed luncheon meat. J. Applied Bactriol., 57: 229-236.
Direct Link  |  

Chang, J.C., 1991. Effect of glucose concentration agar and amount of incoculum on the 6.5% NaCl tolerance test for presumptive identification of enterococci. Chinese J. Microbiol. Immunol., 24: 36-43.

Clark, C.W., L.D. Witter and Z.J. Ordal, 1968. Thermal injury and recovery of Strptococcus faeciumm. Applied Microbiol., 16: 1764-1769.

Cummings, S.P. and D.J. Gilmour, 1995. The effect of NaCl on the growth of a Halomonas species: Accumulation and utilization of compatible solutes. Microbiology, 141: 1413-1418.
CrossRef  |  Direct Link  |  

Gordon, C.L.A. and M.H. Ahmad, 1991. Thermal susceptibility of Streptococcus faecium strains isolated from Frankfurters. Can. J. Microbiol., 37: 609-6012.
PubMed  |  

Hecker, M., C. Heim, U. Volker and L. Wolfel, 1988. Induction of stress proteins by sodium chloride treatment in Bacillus subtilis. Arch. Microbiol., 150: 564-566.

Kaye, D.M.D., 1982. Enterococci: Biologic and epidemiological characteristics and in vitro susceptibility. Arch. Int. Med., 142: 2006-2009.
Direct Link  |  

Kunst, F. and G. Rapoport, 1995. Salt stress is an environmental signal affecting degradative enzyme synthesis in Bacillus subtilis. J. Bactriol., 177: 2403-2407.
Direct Link  |  

Lewis, J.G., R.P. Learmonth and K. Watson, 1995. Induction of heat, freezing and salt tolerance by heat and salt shock in Saccharomyces cerevisiae. Microbiology, 141: 687-694.
PubMed  |  

Magnus, C.A., W.M. Ingledew and A.R. McCurdy, 1986. Thermal resistance of streptococci isolated from pasteurized ham. Can. Inst. Food Sci. Technol. J., 19: 62-67.
Direct Link  |  

Montano, A., M. Bobillo and V.M. Marshal, 1993. Effect of sodium chloride on metabolism of two strains of Lactobacillus plantarum isolated from fermenting green olives. Lett. Applied Microbiol., 16: 315-518.
Direct Link  |  

Perez, B.S., P.L. Lorenzo, M.L. Garcia, P.E. Hernandez and J.A. Ordonez, 1982. Heat resistance of enterococci. Milchwissenschaft, 37: 724-726.

Volker, U., H. Mach, R. Schmid and M. Hecker, 1992. Stress proteins and cross protection by heat shock and salt stress in Bacillus subtilis . J. Gen. Microbiol., 138: 2125-2135.
Direct Link  |  

Volker, U., S. Engelman, B. Maul, S. Riethdorf and A. Volker et al., 1994. Analysis of the induction of general stress proteins of Bacillus subtilis. Microbiology, 140: 741-752.
PubMed  |  

White, H.R., 1953. The heat resistance of Streptococcus faecalis. J. Gen. Microbiol., 8: 27-37.
Direct Link  |  

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