Relative change in free amino acid concentration during growth of <i>P</i>. <i>freudenreichii</i> subsp. <i>shermani</i> CIRM BIA 1 in CdM (A, C and E) and EJ (B, D and F).

<p>(A and B) Alliphatic amino acids; (C and D) basic, acidic + amide amino acids; (E and F) Aromatic, hydroxyl and sulfur-containing amino acids. The arrows indicate the main growth phases corresponding to each incubation medium: exponential (Exp), early stationary (E.Stat) and late stationary phase (L.Stat).</p

Two-dimensional analysis of protein expression during growth of <i>P</i>. <i>freudenreichii</i> subsp. <i>shermani</i> CIRM BIA 1 in EJ and in CdM.

<p>(A) Neosynthesized proteins were radiolabeled with ³⁵S amino acids in both media during indicated duration: lag phase (early), the beginning of the exponential phase (early exponential), the exponential and early stationary phases. (B) Cellular proteins accumulated during growth were Coomassie blue stained.</p

Growth and survival of <i>P</i>. <i>freudenreichii</i> subsp. <i>shermani</i> CIRM BIA 1 in EJ and CdM

<p>(A) growth curve and (B) Live/dead staining of the bacterial cells in the exponential (Exp), early stationary (E.Stat) and late stationary phase (L.Stat) of growth in CdM (<b>black dot</b>) and in EJ (<b>white dot</b>).</p

<i>P</i>. <i>freudenreichii</i> subsp. <i>shermani</i> CIRM BIA 1 tolerance to digestive stresses.

<p>Propionibacteria were harvested at different stages of growth in CdM black square or in EJ white square, prior to acid (A, pH 2) or bile salts (B, 1 g L^-1) challenges. Surviving bacteria were then counted by CFU enumeration. Means with different lower case superscript letters (a-b) differ significantly (<i>P</i> < 0.05) in italic groups for CdM and in normal case groups for EJ.</p

Proteins differentially expressed after growth of <i>P</i>. <i>freudenreichii</i> subsp. <i>shermani</i> CIRM BIA 1 in EJ and in CdM and identified by on line coupling NanoLC-ESI-Q-TOF tandem mass spectrometry.

<p>*: Fold changes correspond to the protein overexpressed with a minimum fold change of 1.2 in the CdM or EJ determined by image analysis</p><p>**: e-value is the number of times a given peptide score will be achieved by incorrect matches from a database search. Protein identifications were automatically validated when they showed at least two unique peptides with an e-value below 0.05 corresponding to log(e-value) < -1.30</p><p>Proteins differentially expressed after growth of <i>P</i>. <i>freudenreichii</i> subsp. <i>shermani</i> CIRM BIA 1 in EJ and in CdM and identified by on line coupling NanoLC-ESI-Q-TOF tandem mass spectrometry.</p

Microscopic observation of internalized <i>S</i>. <i>aureus</i>.

<p>Internalization of <i>S</i>. <i>aureus</i> N305 as observed by transmission electron microscopy. <i>S</i>. <i>aureus</i> N305 (at an MOI of 100:1) was incubated for 2 h with bMEC either alone (A, B) or in the presence of <i>L</i>. <i>casei</i> BL23 wt (C, D) or <i>srtA2</i> mutant (E, F) strains, at an MOI of 2,000:1.</p

Impact of <i>L</i>. <i>casei</i> BL380 (BL23 <i>bnaG</i>) on <i>S</i>. <i>aureus</i> internalization into bMEC.

<p>Internalization rates of <i>S</i>. <i>aureus</i> N305 after 2 h of interaction with bMEC and co-incubation with <i>L</i>. <i>casei</i> BL23 and <i>L</i>. <i>casei</i> BL380 (<i>bnaG</i>) at an MOI of 2,000:1. <i>S</i>. <i>aureus</i> was used at an MOI of 100:1. The internalization assay of <i>S</i>. <i>aureus</i> alone was used as a reference. Internalization rates were then defined as the internalized <i>S</i>. <i>aureus</i> population in the presence of the different <i>L</i>. <i>casei</i> strains relative to the internalized <i>S</i>. <i>aureus</i> population of the reference experiment. Data are presented as means ± standard deviations. Each experiment was done in triplicate, and differences between groups were compared using one-way ANOVA with Bonferroni's Multiple Comparison Test. *: P < 0.05.</p

Auto-aggregation capacities of <i>L</i>. <i>casei</i> BL23 wt and <i>srtA2</i> strains.

<p>Strains were grown in UF milk medium for 48 h at 37°C. Auto-aggregation was evaluated by spectrophotometry (600 nm) and expressed as the auto-aggregation percentage. Cell suspension OD after growth (48 h) and homogenization was used as a reference (100%). Data are presented as means ± standard deviations. Each experiment was done in triplicate, and differences between groups were compared using Student’s t-test. *: P < 0.05.</p

Resistance of <i>L</i>. <i>casei</i> BL23 wt and <i>srtA2</i> strains to H₂O₂.

<p>Resistance of <i>L</i>. <i>casei</i> BL23 wt (●, ○) and <i>srtA2</i> (■, □) strains to H₂O₂ was evaluated in the stationary phase of growth of <i>L</i>. <i>casei</i> (24h—MRS). The residual population was evaluated at 0, 10, 20 and 30 min after exposure to 0.25% (●, ■) and 0.5% H₂O₂ (○, □). Data are presented as means ± standard deviations. Each experiment was done in triplicate, and differences between groups were compared using Student’s t-test. *: P < 0.05.</p

Cell surface proteome of <i>L</i>. <i>casei</i> BL23 wt and <i>srtA2</i> mutant as determined by enzymatic shaving.

<p>Cell surface proteome of <i>L</i>. <i>casei</i> BL23 wt and <i>srtA2</i> mutant as determined by enzymatic shaving.</p