Fig. 7

ADI release is the consequence of bacterial cell damage and protein leakage. (a) Changes in the viability of L. lactis Lc4 cells during cultivation with respect to ADI enzymatic activity. The enzymatic activity, as an amount of L-citrulline produced by ADI, was measured for F > 50 kDa obtained from 25 ml of CFS. Data points are represented as mean +/- SD (n = 3 independent biological replicates). (b) SDS-PAGE gel analysis of protein profiles of Lc4 F > 50 kDa obtained from different bacterial cultivation time points. Protein concentration was measured with the Bradford method and equal protein amounts of each sample were resolved in SDS-PAGE gel. (c) SEM image of Lc4 strain cells after 24 h of cultivation. Blue rectangles indicate cells undergoing the lysis process. Red ovals mark possible cytoplasmic blebs and/or leakage events. (d) TEM image of cytoplasm leakage from Lc4 cells. The red oval indicates altered membrane integrity