title: The CasKR two-component system is required for the growth of mesophilic and psychrotolerant Bacillus cereus strains at low temperatures.
abstract: The different strains of Bacillus cereus can grow at temperatures covering a very diverse range. Some B. cereus strains can grow in chilled food and consequently cause food poisoning. We have identified a new sensor/regulator mechanism involved in low-temperature B. cereus growth. Construction of a mutant of this two-component system enabled us to show that this system, called CasKR, is required for growth at the minimal temperature (Tmin). CasKR was also involved in optimal cold growth above Tmin and in cell survival below Tmin. Microscopic observation showed that CasKR plays a key role in cell shape during cold growth. Introducing the casKR genes in a ΔcasKR mutant restored its ability to grow at Tmin. Although it was first identified in the ATCC 14579 model strain, this mechanism has been conserved in most strains of the B. cereus group. We show that the role of CasKR in cold growth is similar in other B. cereus sensu lato strains with different growth temperature ranges, including psychrotolerant strains.
authors: INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, Avignon, France.
authors: Sara Esther
authors: SE
authors: Diomandé
authors: Stéphanie
authors: S
authors: Chamot
authors: Vera
authors: V
authors: Antolinos
authors: Florian
authors: F
authors: Vasai
authors: Marie-Hélène
authors: MH
authors: Guinebretière
authors: Isabelle
authors: I
authors: Bornard
authors: Christophe
authors: C
authors: Nguyen-the
authors: Véronique
authors: V
authors: Broussolle
authors: Julien
authors: J
authors: Brillard
mesh_terms: D001409:Bacillus cereus / Q000235:genetics / Q000254:growth & development* / Q000528:radiation effects*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors; D011494:Protein Kinases