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Journal of Biological Sciences

Year: 2002 | Volume: 2 | Issue: 7 | Page No.: 502-504
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Research Article

Effect of pH of the Medium During Growth on Heat Tolerance of Enterococcus faecium and Enterococcus faecalis

Mushtaq Ahmad, David G. Smith and Shahid Mahboob

ABSTRACT

Effect of pH of the growth medium on heat tolerance was investigated in Enterococcus faecium BAR1 and Enterococcus faecalis MI2. The heat tolerance was determined at 55, 60 and 62.5oC for half an hour. Cells of both isolates were grown to exponential phase at pH 5 or 7.4. Cells grown at 37oC at pH 5.0 were found tolerant to heat treatment as compared with cells grown at pH 7.4. Cells did not differ in their tolerance to heat at 55oC but at 60 and 62.5oC, cells of E. faecium BAR1 were found more heat tolerant than the cells of sE. faecalis MI2. The acidic pH of the growth medium had affected the susceptibility of E. faecium BAR1 and E. faecalis MI2 on heat tolerance. The cells grown at acidic pH showed greater heat tolerance that the cells grown at neutral pH.
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