Abstract
An experiment was performed to study the characteristics of bacteria of raw meat from the viewpoint of the range of temperature required for bacterial growth; 1, 056 strains of bacteria isolated from refrigerated and frozen raw meat by incubation at 7, 25, and 37°C were used. They were observed for growth at 7-37°C and identified.
1) Of the strains isolated by incubation at 7°C, two (0.4%) belonged to the category of so-called obligate psychrophilic bacteria, which grew only within a range of temperature from 7 to 20°C.
2) Among the strains isolated by incubation at 7 and 25°C, 61.8% and 32.5%, respectively, could not grow at 35°C. These strains belonged to the groups of bacteria growing at 7-25°C, 7-30°C, or 7-32°C.
3) All the strains isolated at 7 and 37°C could grow at 25°C, except for the two mentioned in 1) above. Therefore, incubation at 25°C was presumed to result in detection of almost all the bacteria that could grow on incubation at 7 and 37°C.
4) Principal components of the groups of bacteria classified on the basis of the range of temperature for growth were as follows: Lactobacillus in the group of bacteria growing at 7-20°C, coryneforms in those growing at 7-25°C and at 7-30°C, coryneforms and Pseudomonas in those growing at 7-32°C and at 7-35°C, coryneforms, Lactobacillus, and Pseudomonas in that growing at 7-37°C, and Micrococcus in that growing at 25-37°C.
