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Bacillus cereus ATCC 14579 RpoN (Sigma 54) Is a Pleiotropic Regulator of Growth, Carbohydrate Metabolism, Motility, Biofilm Formation and Toxin Production.

Hayrapetyan H, Tempelaars M, Nierop Groot M, Abee T - PLoS ONE (2015)

Bottom Line: The mutant was impaired in many different cellular functions including low temperature and anaerobic growth, carbohydrate metabolism, sporulation and toxin production.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus

Growth at low temperature.Growth of B. cereus ATCC 14579 WT, ΔrpoN and ΔrpoN-comp at 12°C. a) Aerated growth in BHI monitored up to 96 h, b) growth on BHI agar plate, picture was taken on day 12.
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pone.0134872.g005: Growth at low temperature.Growth of B. cereus ATCC 14579 WT, ΔrpoN and ΔrpoN-comp at 12°C. a) Aerated growth in BHI monitored up to 96 h, b) growth on BHI agar plate, picture was taken on day 12.

Mentions: The rpoN mutant was unable to grow at 12°C with aeration in BHI broth over a period of 4 days during which the OD at 600 nm was measured (Fig 5a). Upon prolonged incubation on BHI agar plates the colonies of the mutant were smaller and almost invisible compared to the WT and complemented strain when grown for up to 12 days at 12°C (Fig 5b).


Bacillus cereus ATCC 14579 RpoN (Sigma 54) Is a Pleiotropic Regulator of Growth, Carbohydrate Metabolism, Motility, Biofilm Formation and Toxin Production.

Hayrapetyan H, Tempelaars M, Nierop Groot M, Abee T - PLoS ONE (2015)

Growth at low temperature.Growth of B. cereus ATCC 14579 WT, ΔrpoN and ΔrpoN-comp at 12°C. a) Aerated growth in BHI monitored up to 96 h, b) growth on BHI agar plate, picture was taken on day 12.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4524646&req=5

pone.0134872.g005: Growth at low temperature.Growth of B. cereus ATCC 14579 WT, ΔrpoN and ΔrpoN-comp at 12°C. a) Aerated growth in BHI monitored up to 96 h, b) growth on BHI agar plate, picture was taken on day 12.
Mentions: The rpoN mutant was unable to grow at 12°C with aeration in BHI broth over a period of 4 days during which the OD at 600 nm was measured (Fig 5a). Upon prolonged incubation on BHI agar plates the colonies of the mutant were smaller and almost invisible compared to the WT and complemented strain when grown for up to 12 days at 12°C (Fig 5b).

Bottom Line: The mutant was impaired in many different cellular functions including low temperature and anaerobic growth, carbohydrate metabolism, sporulation and toxin production.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus