Survival of Klebsiella pneumoniae Heated in Buffer and in Tomato Juice

Abstract

Klebsiella pneumoniae survived nonexponentially when heated in phosphate buffers at pH 7.0 and 4.3 and in tomato juice at pH 4.3. At 60 C, an initial inoculum of 109 cfu/ml decreased by 6 log units in 15 min, with a long tailing of the survivors to 75 min of heating. At 67 C, total destruction of K. pneumoniae was attained in both buffers at 25 min, and in tomato juice at 40 min. Factors influencing heat resistance of the bacterium are discussed.