CHANGES OF VIABILITY AND PROTEIN-SYNTHESIZING ACTIVITY IN PSYCHROTROPHIC AND MESOPHILIC BACTERIA BY CHILLING AT 0-DEGREES

When Pseudomonas sp. Strain 351 (P. 351), a psychrotroph, and Pseudomonas aeruginosa and Bacillus subtilis, mesophiles, were exposed to 0°, viability of P. 351 was little changed during the chilling for 16 days, whereas that of P. Aeruginosa and B. Subtilis was reduced to about 40 % after 2 and 4 days of chilling, and was lost completely after 16 and 8 days, respectively. Protein-synthesizing activity of P. 351 at 0°, 10°, and 20° was little changed or stimulated by chilling for 4 days, whereas that of P. Aeruginosa was markedly depressed by the same treatment. However, RNA synthesis was activated by chilling for 4 days both in P. 351 and P. Aeruginosa. From these results, cold-sensitivity of the protein-synthesizing system in P. Aeruginosa seems to be closely related with diminution of its viability in low temperatures. © 1979, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.