Figure 4. Effects of temperature and stress response factors on OMV production.

(A) OMVs were isolated from Y. pestis cultured at either 26°C or 37°C, and total protein abundance associated with the OMVs was measured. Protein concentrations were normalized to the OD₆₂₀ of the bacterial cultures. (B) Wild-type Y. pestis or strains lacking the genes for RseA, Hfq, or Lpp were cultured at 37°C as above and OMVs were isolated and total associated protein was measured and normalized to the OD₆₂₀. For cold shock experiments, bacteria were placed in an ice water bath for one h before proceeding. One experiment representative of two biological replicates is shown. The mean and SE are shown. *p<0.05, **p<0.005 (student's t–test).