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The Recovery of Sublethally Injured Escherichia coli from Frozen Meat
Author(s) -
MACKEY B. M.,
DERRICK CHRISTINE M.,
THOMAS JOSEPHINE A.
Publication year - 1980
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1980.tb01231.x
Subject(s) - incubation , escherichia coli , agar , incubation period , microbiology and biotechnology , food science , resuscitation , biology , membrane , bacterial growth , bacteria , chemistry , biochemistry , medicine , surgery , genetics , gene
Sublethal injury to Escherichia coli , measured as the inability of surviving cells to grow on media containing bile salts, was monitored during frozen storage on meat at —5, —10 and —20° C. More rapid increases in injury occurred at the higher subzero temperatures and log phase cells were more susceptible than those in the stationary phase of growth. Repair of injury in non‐selective liquid media took between 2 and 6 h at 25° and was often accompanied by an increase in total viable count. Incubation for a fixed period in broth was, therefore, unsuitable for the quantitative recovery of freeze‐injured Esch. coli. Resuscitation on membrane filters avoided confusing repair of injury with multiplication of uninjured or repaired cells. The mean recovery of injured cells following incubation on membranes for 4 h at 35°C on tryptone soya agar, was 94%.