Fig. 2

Morphological and physiological characteristics of evolved strains. A Comparison of colony morphology between evolved population and parental strain. Overnight culture was spread on plates cultured at 30 °C, photographs were taken after 24 h. B Comparison of antibacterial activity. Diluted strains were spread on plates mixed with Sporisorium scitamineum, cultured at 30 °C for 24 h, and photographed. C Randomly selected mutants exhibited enhanced macrolactins production over the parental strain. Strains were cultured in ISP–50 medium at 30 °C for 24 h, products were measured by HPLC, values and error bars represent mean and standard deviation values (n = 3 cultivations). D Cell sizes are reduced in the evolved strain under non-stress conditions. Photomicrographs were performed with a scanning electron microscope. Image-Pro (Plus 6.0) was used to measure the cell size by counting 140 cells in each strain