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

Abstract

When Pseudomonas sp. strain 351 (P. 351), a psychrotroph, and P. aeruginosa and Bacillus subtilis, mesophiles, were exposed to 0.degree. C, viability of P. 351 was little changed during the chilling for 16 days, whereas that of P. aeruginsoa 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.degree. C was little changed or stimulated by chilling for 4 days, whereas that of P. aeruginosa was markedly depressed by the same treatment. RNA synthesis was activated by chilling for 4 days both in P. 351 and P. aeruginosa. Cold-sensitivity of the protein-synthesizing system in P. aeruginosa seems to be closely lated with diminution of its viability in low temperatures.