FIG. 5.

Protein patterns determined for L. delbrueckii subsp. bulgaricus strains 546 and V5221 by 2-DE imaging of [³⁵S]methionine-labeled polypeptides from both strains in exponential growth phase. Cells were grown in MPL medium, centrifuged, and resuspended in MPL medium. (A and B) Control conditions for strains 546 and V5221, respectively. (C and D) Protein patterns after heat shock for strains 546 and V5221, respectively. Cells were grown and prepared in the same manner as for the controls, except that they were heated at 65°C for 15 min. Abscissa, pH range; ordinate, kilodaltons. Symbols: ▵, proteins induced in strain 546 after heat shock at 65°C for 15 min (HSPs); □, newly synthesized proteins (NS1, NS2, and NS3) in strain 546 after heat shock; ○, proteins up-regulated in strain V5221 and down-regulated in strain 546 after heat shock; , proteins down-regulated during thermal stress; ◊, protein remaining unchanged during thermal stress.