Abstract
When Lactococcus lactis strains were exposed directly to the lethal temperature of 50 C for 30 ;min, 0.1–31% of the cells survived. However, when pre-exposed to 40 °C, prior to exposure at 50 °C, 4–61% of the cells survived. A plasmid carrying a unique heat shock gene from the thermophile Streptococcus thermophilus was cloned into L. ;lactis. When the transformed cells were cultivated at 30 °C the introduction of the plasmid had no obvious effect on the growth of L. ;lactis. However, when the temperature was abruptly shifted from 30 °C to 42 °C at mid-growth phase the growth decreased by 50%.
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Kim, W.S., Ren, J. & Dunn, N.W. Assessment of the tolerance of Lactococcus lactis cells at elevated temperatures. Biotechnology Letters 23, 1141–1145 (2001). https://doi.org/10.1023/A:1010524303261
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DOI: https://doi.org/10.1023/A:1010524303261