0000000001155618
AUTHOR
Julia Hauck Tiburski
Comprehensive study of the heat resistance of dried Bacillus subtilis spores
In response to starvation, species from the genre Bacillus are able to form metabolicallydormant spores which are very resistant to multiple forms of stress. They are found in quitehigh concentrations in some dried foods which, upon rehydration, may lead to food deterioration or food-borne diseases. Moreover, their destruction is rather difficult and mostof the techniques commonly used to treat dry foods result in a very low spore inactivation.The aim of this work is to better understand the role spore hydration in the inactivation ofdried Bacillus subtilis spores. A fundamental study was conducted using DifferentialScanning Calorimetry pans as reactors to perform a heat treatment in dried …
Extremely rapid acclimation of Escherichia coli to high temperature over a few generations of a fed-batch culture during slow warming
This study aimed to demonstrate that adequate slow heating rate allows two strains of Escherichia coli rapid acclimation to higher temperature than upper growth and survival limits known to be strain-dependent. A laboratory (K12-TG1) and an environmental (DPD3084) strain of E. coli were subjected to rapid (few seconds) or slow warming (1 degrees C 12 h(-1)) in order to (re) evaluate upper survival and growth limits. The slow warming was applied from the ancestral temperature 37 degrees C to total cell death 46-54 degrees C: about 30 generations were propagated. Upper survival and growth limits for rapid warming (46 degrees C) were lower than for slow warming (46-54 degrees C). The thermal l…