EFFECT OF TEMPERATURE ON GROWTH OF OBLIGATELY PSYCHROPHILIC BACTERIA

Effect of temperature on the growth of five obligately psychrophilic bacteria and behavior of Curtobacterium psychrophilum strain 27-O-b at elevated temperatures were studied. Most of obligate psychrophiles showed lower growth activities than a facultative psychrophile at lower temperature. Arrhenius plots of the growth of most of obligate psychrophiles were linear from a temperature little below their optimum growth temperature to 0°. However, there was a deviation in Arrhenius plots of Cytophaga antarctica strain 16-O-d and a facultative psychrophile, Pseudomonas fluorescens strain 76-O-a. Therefore, it seems unreasonable to characterize psychrophiles only from the points of growth activities at lower temperature and/or a pattern of the Arrhenius plot. When C. psychrophilum was transferred to elevated temperatures after preincubation at the optimum growth temperature of 9°, it exhibited faster growth for the first few hours than at 9°, and then the growth ceased.