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Nutrient limitation and oxidative stress induce the promoter of acetate operon in Salmonella Typhimurium.

Authors :
Sarkhel R
Priyadarsini S
Mahawar M
Source :
Archives of microbiology [Arch Microbiol] 2024 Feb 27; Vol. 206 (3), pp. 126. Date of Electronic Publication: 2024 Feb 27.
Publication Year :
2024

Abstract

Glyoxylate shunt is an important pathway for microorganisms to survive under multiple stresses. One of its enzymes, malate synthase (encoded by aceB gene), has been widely speculated for its contribution to both the pathogenesis and virulence of various microorganisms. We have previously demonstrated that malate synthase (MS) is required for the growth of Salmonella Typhimurium (S. Typhimurium) under carbon starvation and survival under oxidative stress conditions. The aceB gene is encoded by the acetate operon in S. Typhimurium. We attempted to study the activity of acetate promoter under both the starvation and oxidative stress conditions in a heterologous system. The lac promoter of the pUC19 plasmid was substituted with the putative promoter sequence of the acetate operon of S. Typhimurium upstream to the lacZ gene and transformed the vector construct into E. coli NEBα cells. The transformed cells were subjected to the stress conditions mentioned above. We observed a fourfold increase in the β-galactosidase activity in these cells resulting from the upregulation of the lacZ gene in the stationary phase of cell growth (nutrient deprived) as compared to the mid-log phase. Following exposure of stationary phase cells to hypochlorite-induced oxidative stress, we further observed a 1.6-fold increase in β galactosidase activity. These data suggest the induction of promoter activity of the acetate operon under carbon starvation and oxidative stress conditions. Thus, these observations corroborate our previous findings regarding the upregulation of aceB expression under stressful environments.<br /> (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Details

Language :
English
ISSN :
1432-072X
Volume :
206
Issue :
3
Database :
MEDLINE
Journal :
Archives of microbiology
Publication Type :
Academic Journal
Accession number :
38411730
Full Text :
https://doi.org/10.1007/s00203-024-03863-2