Fig. 8

Effects of crude filtrates of K. humilis MAW1 cultures on the growth of E. coli strain AB1157. (a) Number of viable cells of E. coli strain AB1157 (CFU, colony forming units) after overnight growth under standard conditions (37 °C with shaking) in the following media: LB alone, or equal (1:1) mixtures of LB: neutral YPD (pH 7.0), LB: acidic YPD (pH 5.0), LB: culture filtrate after K. humilis MAW1 growth in acidic YPD (pH 4.5) or LB: culture filtrate after K. humilis MAW1 growth in neutral YPD (pH 7.0). Data represent the means ± SD from four biological replicates, the statistical significance of two-sided t-test is shown (0.05 ≥ *> 0.01 ≥ **> 0.001 ≥ ***); (b) Microscopic images of E. coli AB1157 stained with fuchsin (enhanced in Fiji) and the level of argE3→Arg⁺ reversion (mean ± SD from four biological replicates) after overnight growth under the aforementioned conditions