Fig. 4

Kinetics of production, purification, and mass spectrometry analysis of garvicin Q of L. petauri B1726. A Optical density (OD₆₀₀, solid line) and pH (dashed line) of L. petauri B1726 cultures grown in M17 medium supplemented with 2% glucose. The cells were incubated statically in 50 ml Schott glass bottles at 30 °C. B Antimicrobial activity in SN from (A) harvested at indicated time points. Activity was tested by incubating the indicator strain L. innocua LMG2785 with serial two-fold dilutions of SN. Values in (A) and (B) are mean ± standard deviation of n = 3 independent cultures. C Hydrophobic interaction chromatography (upper panel) and subsequent reverse-phase chromatography (lower panel) to purify garvicin Q from L. petauri B1726 SN after cultivation for 24 h in M17 medium supplemented with 2% glucose A. D LC–MS analysis of combined RPC elution fraction harbouring antimicrobial activity. The peaks with mass to charge ratios (m/z) of 1069.1500, 891.1142 and 763.9628 correspond to garvicin Q with five, six or seven positive charges, respectively