Difference in Injury of Cells of Vibrio parahaemolyticus Produced by Heat and Cold Stresses in liquid and Solid Menstrual
- 1 October 1978
- journal article
- research article
- Published by Elsevier in Journal of Food Protection
- Vol. 41 (10) , 764-767
- https://doi.org/10.4315/0362-028x-41.10.764
Abstract
Cells of Vibrio parahaemolyticus were stressed by heat, cold or heat-cold treatments of 45 C for 12 h, 0 C for 24 h or both. The five menstrua in which cells were stressed were 0.1 M phosphate buffer with 3% NaCl (B + 3%), 0.25 - strength Marine Broth (0.25 × MB) Trypticase Soy Broth with 3% NaCl (TSB + 3%) and Trypticase Soy Agar with 3 or 7% NaCl (TSA + 3% or TSA + 7%). The chill stress produced no cell injury, measured as the difference in colony counts in TSA+3% and TSA+7%, in the three liquid menstrua but caused more than 4 logs of cell injury in the solid menstrua compared to controls. The heat stress caused 2.5- and 1.5-log increases in the number of injured cells from B + 3% or 0.25 × MB, respectively. Cells heat-stressed in TSB + 3% showed no decline in colony counts, but those heat-stressed in TSA+ 7% produced about a 6-log lower colony count. For cells heated and then chilled in B+3% or 0.25 × MB as the liquid menstruum, the percentages of heat-injured cells that apparently regained tolerance to 7% NaCl when shifted to the cold were about 99.7 and 95.0%, respectively. Conversely, cells that were heated and then chilled in the solid menstrua did not regain tolerance to 7% NaCl. Thus, cell injury was greater and apparently less easily reversed for cells stressed in solid than liquid menstrua.This publication has 1 reference indexed in Scilit:
- Sublethal heat stress of Vibrio parahaemolyticusApplied and Environmental Microbiology, 1976