Abstract: Proteomic analysis was carried out to identify and characterize protein expression in Lactobacillus casei XM2-1. The cytosolic proteins of L. casei XM2-1 at the mid-exponential phase and early stationary phase were resolved by two-dimensional gel electrophoresis. Sixteen proteins revealed significant differences between two growth phases, and seven proteins were identified as stress proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS), which included GroEL, DnaK, Hsp 20-1, Hsp 20-2 and UspA. This will be helpful for improving our understanding of the lg-ATR response in L. casei.

Key words: Lactobacillus casei XM2-1, proteomics, stress protein