Fig. 2

SEM and TEM images of the morphology of bacterial cells post-incubated with positively charged PS microplastics (200 nm) and nanoplastics (80 nm). B. subtilis (a), E. coli (b), and D. radiodurans (c) cells at OD₆₀₀ of 1.0 were incubated with 100 µg/mL PS-NH₂ (200 nm or 80 nm) for 3 h at 37 ^oC or 30 ^oC, respectively. Untreated (control), cells only treated with buffer solution. Red arrow, nanoparticles. Scale bar, 1 μm. d Relative level of intracellular nanoplastics per cell with intact morphology after incubated with 100 µg/mL PS-NH₂ (80 nm) for 3 h, respectively. Average numbers of nanoplastics in the cell cross section from TEM images were used to represent the relative level of intracellular nanoplastics per cell. The error bars represent the standard deviations from five-independent statistics; **, P < 0.01; ***, P < 0.005, significant difference (student’s t-test). BS, B. subtilis; EC, E. coli; DR, D. radiodurans. e Schematic diagram of cell membrane structure of B. subtilis, E. coli and D. radiodurans