Figure 2

Expression and purification of rEntA. A, Total secreted protein level and antimicrobial titer of the fermentation supernatants of recombinant P. pastoris at the shake-flask level (bars represent the standard error of the mean). B, Antimicrobial activity of the fermentation supernatants of recombinant P. pastoris at the fermenter level. 1-9, 50 μl supernatant taken at 0, 12, 24, 36, 48, 60, 72, 84, and 90 h of induction, respectively; 10, 1 μg ampicillin. C, The total secreted protein level and antimicrobial titer in the fermenter level (bars represent the standard error of the mean). D, Tricine-SDS-PAGE analysis of rEntA secreted in the fermentation supernatant of P. pastoris cultures at the fermenter level. Lane M, 5 μl molecular mass standards (from top to bottom: 40, 25, 15, 10, 4.6 and 1.7 kDa); Lanes 1-9, 20 μl supernatant taken at 0, 12, 24, 36, 48, 60, 72, 84 and 90 h of induction, respectively. E, MALDI-TOF map of rEntA. F, Purification and identification of rEntA. Lane 1, purified rEntA (0.1 μg); Lane M, 5 μl molecular mass standards (from top to bottom: 40, 25, 15, 10, 4.6 and 1.7 kDa). Lane 2, 10 μl of rEntA supernatant taken at 24 h of induction.