Characterization of the protein-synthesis dependent adaptive acid tolerance response in Lactobacillus acidophilus.
Exposure of L. acidophilus CRL 639 cells to sublethal adaptive acid conditions (pH 5.0 for 60 min) was found to confer protection against subsequent exposure to lethal pH (pH 3.0). Adaptation, which only occurred in complex media, was dependent on de novo protein synthesis and was inhibited by amino acid analogues. There was no modification in the protein synthesis rate during adaptation, but the protein degradation rate decreased. Synthesis of acid stress proteins may increase the stability of pre-existing proteins. By 2D-PAGE, induction of nine acid stress proteins and repression of several housekeeping proteins was observed. Putative heat shock proteins DnaK, DnaJ, GrpE, GroES and GroEL (70, 43, 24, 10 and 55 kDa, respectively) were among the proteins whose synthesis was induced in response to acid adaptation.
Lorca
Graciela L
GL
Centro de Referencia para Lactobacilos, CONICET, Tucumán, Argentina. g_lorca@yahoo.com
Font de Valdez
Graciela
G
Ljungh
Asa
A
D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000378:metabolism*; D003470:Culture Media; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000378:metabolism*; D018869:Heat-Shock Response; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000494:pharmacology*; D007779:Lactobacillus acidophilus / Q000187:drug effects* / Q000254:growth & development
D001426:Bacterial Proteins; D003470:Culture Media; D006360:Heat-Shock Proteins; D019344:Lactic Acid