Several cold tolerance mechanisms of Group I C. botulinum
were shown to be similar to those of other Gram-positive
bacteria. These include the cold-shock proteins (Csps) that
are understood to assist translation by dismantling RNA secondary
structures and to function as transcription antiterminators. Three Csp-encoding homologs were
identified in the ATCC 3502 genome, of which cspB was
shown to encode the major cold-related Csp . Interestingly,
while Csps are proposed to represent universally
conserved cold-tolerance mechanisms , the psychrotrophic
Group II strains appeared to lack Csp homologs in their genomes
. This finding raises questions about the mechanisms
these organisms utilize to withstand considerably low
temperatures; investigation of such mechanisms should be a
focus of future research. Importance of Csps in environmental
stress conditions other than low temperature has been
demonstrated in the Gram-positive Listeria monocytogenes