FIG. 4.

Comparison of growth rates and psychrotolerance indices. Cultures were grown in plate count broth at 10°C (A), 28°C (B), and 42°C (C). The optical densities were measured at 600 nm, and the growth rates were determined during exponential growth as generations per hour (gen/h). The growth rates are plotted against the percentage of psychrotolerant signatures as determined by restriction digest with SspI (Fig. 1). The experiment was done two to six times, and the means of the populations were determined. Standard errors were less than 20%. The exact psychrotolerance indices were as follows: WSBC10028, 0%; WSBC10030, 0%; WSBC10312, 0%; WSBC10250, 10%; WSBC10246, 12.5%; WSBC10316, 14.3%; HER1418, 25%; HER1410, 33%; WSBC10310, 33%; WSBC10313, 43%; WSBC10314, 50%; WSBC10315, 50%; WSBC10297, 87%; WSBC10311, 100%; WSBC10201, 100%; WSBC10204, 100%; WSBC10206, 100%; WSBC10276, 100%; WSBC10279, 100%.