*3.4. Proteomic Analysis*

### 3.4.1. Protein Extraction and Trypsin Digestion

The bacterial pellet was lysed and protein was extracted as described previously [17]. Protein concentration was measured by the Bradford method [50] using the Bradford Protein Assay Kit (Bio-Rad, Hercules, USA).

Proteolytic in-gel digestion was performed in three biological and two technical replicates: 1) sample, fractionated into 6 parts; 2) total load sample as described previously [51]. Peptides were cleaned using C18 Sep-Pak columns (Waters, Milford, USA) [17].
