Table 1. Listeria monocytogenes.
σB contributions to stress resistance
| Stress condition | σB-dependent genes | Phenotypic data supporting σB contributions | Refs |
|---|---|---|---|
| Acid | gadA and gadCB operon | Survival of ΔsigB strain is five logs lower than wild type when logarithmic- phase cells are exposed to pH 2.5 for 1 h | [29] |
| Osmotic | betL, gbuA, bilEAB and opuCABCD | Reduced ability to use carnitine and betaine as osmoprotectants in ΔsigB strain | [35] |
| Oxidative | lmo0669a and lmo1433 | Survival of stationary-phase ΔsigB strain is one log lower than wild type when exposed to 13 mM CHP for 15 min | [30] |
| Energy | opuCA and carbon metabolism genes (e.g. ldh) | Viability of ΔsigB strain is impaired when glucose is limiting, upon entry into stationary phase and under conditions that deplete intracellular ATP | [30] |
| Cold or freezing | ltrC (low-temperature requirement C) | σB is not required during growth in rich media at 4 °C or for survival after freeze–thaw cycles, but contributes to growth in minimal media and in meats at low temperatures | [29,74–76] |
| High hydrostatic pressure | Not determined | Survival of ΔsigB strain is four logs lower than wild type at 350 MPa after 28 min | [29] |
| Arsenate | lmo2230 (encodes a protein similar to arsenate reductase) | Not determined | [24,25] |
a
lmo0669 might contribute to the acid-stress response at pH 4.5 [77].