2.6. Growth of bacteria and sample preparation
All bacteria were subcultured overnight at 37 C on Columbia
blood agar one day prior to preparation for VOC analysis. After
overnight incubation on blood agar at 37 C bacteria were
inoculated in sterile Listeria enrichment broth (LEB) with added
Listeria selective enrichment supplement. The enzyme substrates
2-nitrophenyl-b-D-glucoside and 2-[(3-fluorophenyl) carbamoylamino]acetic
acid (Fig. 1) were separately dissolved in LEB and
added to sterile LEB with selective agents