Fig. 2: In vitro resistance of LCB against environmental assaults.
a Growth curves of uncoated EcN and LCB cultured in LB medium at 37 °C and the OD600 was recorded at 30 min intervals using a microplate reader. b–i Equal amounts of uncoated EcN and LCB were exposed to the following: b an antibiotic cocktail of ampicillin and apramycin, c a strong acid (pH 2), d a strong alkali (pH 11), e 30% (v/v) ethanol, f 50% (v/v) ethanol, g 0.3 mg ml−1 bile salts, h SGF (pH 1.2) supplemented with pepsin and i SIF (pH 6.8) containing trypsin at 37 °C. After the indicated time points, 50 μl of each sample was washed twice with fresh LB, spread onto LB agar plates and incubated at 37 °C for 24 h before bacterial counting. Error bars represent standard deviation (n = 3). Significance was assessed using Student’s t-test, giving p values, *p < 0.05, **p < 0.01, ***p < 0.005.
