FIG. 3.

Freezing tolerance of C. jejuni in MHB and CR. CJ35(squares) and CJ45 (triangles) were stored at −20°C in MHB (closed symbols) or in CR (open symbols). Frozen cultures were thawed only once for assessment of survival. Results for CJ35 in MHB on days 18, 20, 26, and 32, and CJ45 in MHB on day 32 were below the limit of detection (10 CFU/ml). Data shown are means from duplicate plates in a representative experiment and were collected as described in Materials and Methods. The general linear models procedure was utilized to compute all statistical inferences. The slope of each data curve was calculated and compared. The difference between CJ35 in MHB and CJ35 in CR was statistically significant (P < 0.005). A significant difference was also observed between CJ45 in MHB and CJ45 in CR (P < 0.05).