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On the Nature of the Heat Resistance of Thermophilic Bacteria
Author(s) -
Ljunger Claes
Publication year - 1970
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1970.tb06425.x
Subject(s) - thermophile , bacteria , calcium , strain (injury) , potassium , bacillus (shape) , ion , heat stability , heat resistance , potassium phosphate , biochemistry , chemistry , phosphate , food science , biology , microbiology and biotechnology , chromatography , materials science , organic chemistry , genetics , anatomy , composite material
The importance of inorganic ions for the heat stability of thermophilic bacteria was investigated. Cells of Bacillus stearothermophilus , strain 1503, were incubated at elevated temperatures in various media and the number of surviving organisms was determined at suitable intervals. The bacteria rapidly died at temperatures ordinarily employed for their cultivation if the surrounding medium lacked calcium ions. Besides calcium ions, potassium and phosphate ions and glucose, or some other energy source, seemed to be required for the heat stability of the cells. A chemically defined stabilizing medium with these components was developed for the above‐mentioned strain. When any component of this medium was excluded, the heat resistance of this organism was lost. This medium had a stabilizing effect also on the cells of three other strains of B. stearothermophilus. These requirements suggest that the heat stability of thermophilic bacteria is attributable to an active transport of calcium ions from the environment into the cells.