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Thermal inactivation kinetics of Bacillus subtilis spores suspended in buffer and in oils
Author(s) -
Ababouch L.H.,
Grimit L.,
Eddafry R.,
Busta F.F.
Publication year - 1995
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.1365-2672.1995.tb03114.x
Subject(s) - bacillus subtilis , spore , kinetics , buffer (optical fiber) , chemistry , food science , bacillales , thermal , chemical engineering , microbiology and biotechnology , chromatography , bacteria , biology , thermodynamics , genetics , telecommunications , physics , quantum mechanics , computer science , engineering
The heat resistance of Bacillus subtilis 5230 and A spores freeze dried and suspended in buffer or oils was investigated. As expected, spores were more resistant to heat when suspended in oils than in buffer. This was ascribed to the low a w of oils and to their content of free fatty acids. Linear survivor curves were obtained for spores suspended in buffer at 105°C or above and for B. subtilis A spores suspended in a vegetable oil. However, the survivor curves of the spores suspended in mineral oil (strain 5230) or olive oil (both strains) were concave upward with a characteristic tailing. The tailing could not be ascribed to spore clumping or to a specific heat injury that can be circumvented by Ca‐dipicolinate. It is possibly due to another mechanism of injury or to the activation at high temperature of a normally dormant germination system.