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.