title: Bacillus cereus ATCC 14579 RpoN (Sigma 54) Is a Pleiotropic Regulator of Growth, Carbohydrate Metabolism, Motility, Biofilm Formation and Toxin Production.
abstract: Sigma 54 is a transcriptional regulator predicted to play a role in physical interaction of bacteria with their environment, including virulence and biofilm formation. In order to study the role of Sigma 54 in Bacillus cereus, a comparative transcriptome and phenotypic study was performed using B. cereus ATCC 14579 WT, a markerless rpoN deletion mutant, and its complemented strain. The mutant was impaired in many different cellular functions including low temperature and anaerobic growth, carbohydrate metabolism, sporulation and toxin production. Additionally, the mutant showed lack of motility and biofilm formation at air-liquid interphase, and this correlated with absence of flagella, as flagella staining showed only WT and complemented strain to be highly flagellated. Comparative transcriptome analysis of cells harvested at selected time points during growth in aerated and static conditions in BHI revealed large differences in gene expression associated with loss of phenotypes, including significant down regulation of genes in the mutant encoding enzymes involved in degradation of branched chain amino acids, carbohydrate transport and metabolism, flagella synthesis and virulence factors. Our study provides evidence for a pleiotropic role of Sigma 54 in B. cereus supporting its adaptive response and survival in a range of conditions and environments.
authors.affiliation: Laboratory of Food Microbiology, Bornse Weilanden 9, 6708 WG Wageningen University, Wageningen, The Netherlands; Top Institute of Food and Nutrition (TIFN), Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands.
authors.forename: Hasmik
authors.initials: H
authors.lastname: Hayrapetyan
authors.affiliation: Laboratory of Food Microbiology, Bornse Weilanden 9, 6708 WG Wageningen University, Wageningen, The Netherlands; Top Institute of Food and Nutrition (TIFN), Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Tempelaars
authors.affiliation: Top Institute of Food and Nutrition (TIFN), Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands; Food and Biobased research, Wageningen UR, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands.
authors.forename: Masja
authors.initials: M
authors.lastname: Nierop Groot
authors.affiliation: Laboratory of Food Microbiology, Bornse Weilanden 9, 6708 WG Wageningen University, Wageningen, The Netherlands; Top Institute of Food and Nutrition (TIFN), Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands.
authors.forename: Tjakko
authors.initials: T
authors.lastname: Abee
mesh_terms: D001409:Bacillus cereus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001427:Bacterial Toxins / Q000378:metabolism; D018441:Biofilms; D050260:Carbohydrate Metabolism; D004269:DNA, Bacterial / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004768:Enterotoxins / Q000378:metabolism; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D058685:Genetic Pleiotropy; D046228:Microarray Analysis; D009154:Mutation; D051877:RNA Polymerase Sigma 54 / Q000235:genetics / Q000502:physiology*; D012329:RNA, Bacterial / Q000235:genetics; D017384:Sequence Deletion; D013171:Spores, Bacterial; D059467:Transcriptome; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D018076:DNA, Complementary; D004768:Enterotoxins; D012329:RNA, Bacterial; D051877:RNA Polymerase Sigma 54