Identification of novel genes involved in high hydrostatic pressure resistance of Escherichia coli

Gayán Ordás, Elisa (Universidad de Zaragoza) ; Rutten, Nele ; Van Impe, Jan ; Michiels, Chris ; Aertsen, Abram

Resumen: High hydrostatic pressure (HHP) is an interesting hurdle in minimal food processing that aims to synergistically combine different stresses to improve food microbiological safety and stability without compromising quality. For a proper understanding and design of hurdle technology, the cellular impact of the applied stresses on foodborne pathogens should be well-established. To study the mechanism of HHP-mediated cell injury and death, we screened for loss-of-function mutations in E. coli MG1655 that affected HHP sensitivity. More specifically, ca. 6000 random transposon insertion mutants were individually exposed to HHP, after which the phenotype of the most resistant or sensitive mutations was confirmed by de novo gene deletions in the parental strain. We found that disruption of rbsK, rbsR, hdfR and crl decreased HHP resistance, while disruption of sucC and sucD (encoding subunits of the succinyl-CoA synthetase) increased HHP resistance. More detailed study of the tricarboxylic acid cycle enzymes encoded by the sdhCDAB-sucABCD operon surprisingly showed that disruption of the sucA or sucB gene (encoding subunits of the 2-oxoglutarate dehydrogenase complex) notably decreased HHP survival. We also found that the increased HHP resistance of a ¿sucC and ¿sucD mutant was mediated by increased basal RpoS activity levels, although it did not correlate with their heat resistance. Our results reveal that compromising TCA cycle enzymes can profoundly affect HHP resistance in E. coli.

Idioma: Inglés

DOI: 10.1016/j.fm.2018.10.007

Año: 2019

Publicado en: FOOD MICROBIOLOGY 78 (2019), 171-178
ISSN: 0740-0020

Factor impacto JCR: 4.155 (2019)

Categ. JCR: BIOTECHNOLOGY & APPLIED MICROBIOLOGY rank: 33 / 156 = 0.212 (2019) - Q1 - T1
Categ. JCR: FOOD SCIENCE & TECHNOLOGY rank: 25 / 138 = 0.181 (2019) - Q1 - T1
Categ. JCR: MICROBIOLOGY rank: 36 / 133 = 0.271 (2019) - Q2 - T1

Factor impacto SCIMAGO: 1.318 - Food Science (Q1) - Microbiology (Q2)

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Tecnología de Alimentos (Dpto. Produc.Animal Cienc.Ali.)