Effect on morphostructural changes in test microorganisms. Scanning electron micrographs of two Gram-positives (A) Clostridium perfringens ATCC 13124 and (B) Staphylococcus aureus ATCC 12600 and a Gram-negative (C) Escherichia coli ATCC 11775 without or with treatment of the test compounds. White triangles indicate the morphological changes in cells of the test bacteria treated with corresponding compounds: A1, untreated, well divided and rod-shaped cells; A2, undivided, growth inhibited cells; A3, undivided, growth inhibited cells; A4, cell wall and cytoplasmic membrane disruption; A5, growth inhibited cells with cytoplasmic membrane disruption. B1, untreated, smooth and spherical shaped cells; B2, undeveloped cells with cytoplasmic membrane disruption; B3, cells with damaged cell membrane surface; B4, growth inhibited cells with membrane disruption; B5, undivided cells with collision. C1, untreated, well divided elongated cells; C2, wrinkled shaped cells; C3, growth inhibited cells; C4, growth inhibited cells with membrane disruption; C5; growth inhibited cells with collision.