Involvement of the CasK/R two-component system in optimal unsaturation of the Bacillus cereus fatty acids during low-temperature growth

Sara Esther Diomandé, Christophe Nguyen-the, Tjakko Abee, M.H. Tempelaars, Véronique Broussolle, Julien Brillard*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Scopus)

Abstract

Bacillus cereus sensu lato is composed of a set of ubiquitous strains including human pathogens that can survive a range of food processing conditions, grow in refrigerated food, and sometimes cause food poisoning. We previously identified the two-component system CasK/R that plays a key role in cold adaptation. To better understand the CasK/R-controlled mechanisms that support low-temperature adaptation, we performed a transcriptomic analysis on the ATCC 14579 strain and its isogenic ΔcasK/R mutant grown at 12. °C. Several genes involved in fatty acid (FA) metabolism were downregulated in the mutant, including desA and desB encoding FA acyl-lipid desaturases that catalyze the formation of a double-bond on the FA chain in positions Δ 5 and Δ 10, respectively. A lower proportion of FAs presumably unsaturated by DesA was observed in the δcasK/R strain compared to the parental strain while no difference was found for FAs presumably unsaturated by DesB. Addition of phospholipids from egg yolk lecithin rich in unsaturated FAs, to growth medium, abolished the cold-growth impairment of δcasK/R suggesting that exogenous unsaturated FAs can support membrane-level modifications and thus compensate for the decreased production of these FAs in the B. cereus Δ casK/R mutant during growth at low temperature. Our findings indicate that CasK/R is involved in the regulation of FA metabolism, and is necessary for cold adaptation of B. cereus unless an exogenous source of unsaturated FAs is available.

Original languageEnglish
Pages (from-to)110-117
JournalInternational Journal of Food Microbiology
Volume213
DOIs
Publication statusPublished - 2015

Keywords

  • B. cereus
  • Cold adaptation
  • Desaturase
  • TCS
  • Unsaturated FA

Fingerprint

Dive into the research topics of 'Involvement of the CasK/R two-component system in optimal unsaturation of the Bacillus cereus fatty acids during low-temperature growth'. Together they form a unique fingerprint.

Cite this