The two-component system CLO3403/CLO3404 of Clostridium botulinum E1 Beluga is important for cold-shock response and growth at low temperature.

Applied and environmental microbiology

PubMedID: 24185852

Mascher G, Derman Y, Kirk DG, Palonen E, Lindström M, Korkeala H. The two-component system CLO3403/CLO3404 of Clostridium botulinum E1 Beluga is important for cold-shock response and growth at low temperature. Appl Environ Microbiol. 2013;.
In order to survive a temperature downshift, bacteria have to sense the changing environment and adjust their metabolism and structure. Two-component signal transduction systems (TCS) play a central role in sensing and responding to many different environmental stimuli. Although the non-proteolytic (Group II) Clostridium botulinum represents a major hazard in chilled foods, the cold-adaption mechanisms of Group II C. botulinum are not known. Here we show that the TCS CLO3403/CLO3404 of C. botulinum E1 Beluga is involved in cold-shock response and growth at 12°C. The cold shock induced the expression of the genes encoding the histidine kinase (clo3403) and the response regulator (clo3404) over 100-fold after 5 h, relative to a non-shocked culture at the corresponding time point. The involvement of CLO3403/CLO3404 in growth at low temperature was demonstrated by impaired growth of the insertional clo3403 and clo3404 knockout mutants at 12°C compared to the wild-type culture. Additionally, the inactivation of clo3403 had a negative effect on motility. Growth efficiency at 12°C of the TCS mutants and motility of the kinase mutants were restored by introducing a plasmid harboring the operon of the TCS CLO3403/CLO3404. The results suggest that the TCS CLO3403/CLO3404 is important for cold tolerance of C. botulinum E1 Beluga.