PLA Quantification in Microbial Cultures

For PLA quantification in microbial cultures in liquid Ym synthetic medium, 1 mL of culture media was withdrawn at each sampling time and filtrated through 0.45 µm PTFE syringe filters (Thermo Fisher Scientific) to eliminate microorganisms from the supernatant before injection to HPLC apparatus. Regarding micro-malting assays, PLA was quantified in the same extracts as for the T-2 toxin quantification. Analyses of PLA were performed using a Luna C18(2) column (5 µm, 250 × 4.6 mm) and a pre-column with the same characteristics (Phenomenex). The PLA was detected and quantified using HPLC-DAD according to the methodology previously described by Kawtharani et al. [20 (link)]. PLA quantification was calculated according to a standard calibration curve with concentrations ranging between 0.01 and 1 g/L. In micro-malting experiments, PLA concentrations are expressed in g/g.