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Studies of the recovery of frozen Salmonella gallinarum: the roles of cooling rate, initial cell concentration and plating medium *
Author(s) -
RACCACH M.,
JUVEN B.
Publication year - 1973
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1973.tb01708.x
Subject(s) - salmonella , suspension culture , chemistry , recovery rate , suspension (topology) , chromatography , zoology , biology , cell culture , bacteria , genetics , mathematics , homotopy , pure mathematics
Summary Freezing (‐ 40°C) a cell suspension of Salmonella gallinarum at a cooling rate of 18°C per min and an initial cell concentration of 37 × 10 7 cells/ml resulted in a recovery more than five times that obtained from a lower cooling rate (0.5°C per min). Decreasing the initial cell concentration to 12 × 10 3 cells/ml at the higher cooling rate resulted in an increase of only twice the recovery of the lower rate. The percentage recovery from the higher cell concentration was greater than from the lower concentration, only at the higher cooling rate. The apparent recovery of Salmonella gallinarum on a selective medium immediately after freezing, was only 60% of that on a nonselective medium, and decreased to 5% after 1 week of storage at ‐ 20°C.