Differential Involvement of the Five RNA Helicases in Adaptation of Bacillus cereus ATCC 14579 to Low Growth Temperatures

Bacillus cereus ATCC 14579 possesses five RNA helicase-encoding genes overexpressed under cold growth conditions. Out of the five corresponding mutants, only the Delta cshA, Delta cshB, and Delta cshC strains were cold sensitive. Growth of the Delta cshA strain was also reduced at 30 degrees C but not at 37 degrees C. The cold phenotype was restored with the cshA gene for the Delta cshA strain and partially for the Delta cshB strain but not for the Delta cshC strain, suggesting different functions at low temperature.