Response of Lactobacillus helveticus PR4 to heat stress during propagation in cheese whey with a gradient of decreasing temperatures.

ABSTRACT: The heat stress response was studied in Lactobacillus helveticus PR4 during propagation in cheese whey with a gradient of naturally decreasing temperature (55 to 20 degrees C). Growth under a gradient of decreasing temperature was compared to growth at a constant temperature of 42 degrees C. Proteinase, peptidase, and acidification activities of L. helveticus PR4 were found to be higher in cells harvested when 40 degrees C was reached by a gradient of decreasing temperature than in cells grown at constant temperature of 42 degrees C. When cells grown under a temperature gradient were harvested after an initial exposure of 35 min to 55 degrees C followed by decreases in temperature to 40 (3 h), 30 (5 h 30 min), or 20 degrees C (13 h 30 min) and were then compared with cells grown for the sa

SUBMITTER: Di Cagno R 

PROVIDER: S-EPMC1489348 | biostudies-literature | 2006 Jul

REPOSITORIES: biostudies-literature