The present study aims to study the antibacterial activity of food-grade lipidic nanoemulsion (noncationized/cationized) against Bacillus subtilis (BS). Bactericidal activity was ascertained by studying the morphological transitions on BS using transmission electron microscopy (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Morphological changes were witnessed by cell wall breakage, oozing out of cellular contents, loss of cell turgidity and contour. Furthermore, aggregation of cationic nanoemulsion (CaNM) was preferentially observed at apical side of BS construing comparatively more electrostatic attraction between electronegative apical side and CaNM. Resistance response of BS exhibited by apical cell-wall thickening was not able to protect the bacteria due to leakage of cellular content. AFM corroborated its importance in bacteriology, wherein the fragmented cell wall can be "piece-by-piece" identified and sutured back to its appropriate vacant places, thereby, completing the cell wall contour of the ghost cell. Such postmortem analysis of bacterial cell using AFM studies can throw light toward mechanism of cell fragmentation of bacterial cells. SEM study also demonstrated the deformed, fragmented, and amorphous nature of BS construing the bactericidal effect of prepared nanoemulsion.

中文翻译：

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食品级脂质纳米乳存在下枯草芽孢杆菌的形态转变

本研究旨在研究食品级脂质纳米乳（非阳离子化/阳离子化）对枯草芽孢杆菌（BS）的抗菌活性。通过使用透射电子显微镜 (TEM)、原子力显微镜 (AFM) 和扫描电子显微镜 (SEM) 研究 BS 上的形态转变来确定杀菌活性。细胞壁破裂、细胞内容物渗出、细胞肿胀度和轮廓的丧失见证了形态学变化。此外，在 BS 的顶端优先观察到阳离子纳米乳液 (CaNM) 的聚集，这表明带负电的顶端和 CaNM 之间的静电吸引力相对更强。由于细胞内容物的泄漏，由顶端细胞壁增厚表现出的BS的抗性反应不能保护细菌。AFM 证实了它在细菌学中的重要性，其中碎片化的细胞壁可以被“逐片”识别并缝合回其适当的空位，从而完成鬼细胞的细胞壁轮廓。使用 AFM 研究对细菌细胞进行的这种死后分析可以揭示细菌细胞的细胞分裂机制。SEM 研究还证明了 BS 的变形、破碎和无定形性质，这些性质构成了制备的纳米乳剂的杀菌效果。使用 AFM 研究对细菌细胞进行的这种死后分析可以揭示细菌细胞的细胞分裂机制。SEM 研究还证明了 BS 的变形、破碎和无定形性质，这些性质构成了制备的纳米乳剂的杀菌效果。使用 AFM 研究对细菌细胞进行的这种死后分析可以揭示细菌细胞的细胞分裂机制。SEM 研究还证明了 BS 的变形、破碎和无定形性质，这些性质构成了制备的纳米乳剂的杀菌效果。