Single-cell analysis of the disruption of bacteria with a high-pressure jet device: An application of atomic force microscopy
Single-cell analysis of the disruption of bacteria with a high-pressure jet device: An application of atomic force microscopy
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DOI：
10.1016/j.cej.2016.07.112
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发表时间：
2016-12
影响因子：
15.1
通讯作者：
Li Xie;Qian Bao;A. Terada;M. Hosomi
中科院分区：
文献类型：
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作者：
Li Xie;Qian Bao;A. Terada;M. Hosomi
为揭示高压射流装置（HPJD）对污水处理过程中剩余污泥的破碎机理，以大肠杆菌（Escherichia coli）和枯草芽孢杆菌（Bacillus subtilis）为代表，分别对革兰氏阴性菌和革兰氏阳性菌进行HPJD处理，并利用荧光显微镜和原子力显微镜（AFM）对细胞损伤情况进行观察，以及释放的细胞内聚合化合物的分光光度定量。原子力显微镜观察表明，E. coliandB. B.枯草杆菌显示出适度的细胞破坏，包括部分损伤，即，在细胞膜上形成孔隙和裂缝。相反，E.大肠杆菌表现出更广泛的损害，即，细胞分裂和溶解，除了观察到的B.枯草芽孢杆菌两种细菌的受损细胞也表现出细胞间化合物如DNA、蛋白质和多糖的泄漏。这种细胞内大分子的损失导致细胞表面粗糙度增加，细胞直径和弹性降低，与测试的细菌种类无关。结果表明，HPJD处理造成的细胞损伤程度取决于细菌物种的细胞壁和膜结构。总之，我们提出了多种可能的机制，细胞破坏导致HPJD治疗。
The goal of this study was to reveal the mechanism of bacterial cell disruption by a high-pressure jet device (HPJD) for the reduction of excess sludge produced during wastewater treatment.Escherichia coliandBacillus subtilis, representative Gram-negative and Gram-positive bacteria respectively, were subjected to HPJD treatment followed by observation of the damaged cells with epifluorescence microscopy and atomic force microscopy (AFM), as well as spectrophotometric quantification of the released intracellular polymeric compounds. The AFM observations demonstrated that the types of cell damage incurred byE. coliandB. subtiliswere distinct.B. subtilisshowed modest cell disruption comprising partial damage,i.e., the formation of pores and cracks on the cell envelope. In contrast,E. colishowed more extensive damage,i.e., cell cleavage and lysis, in addition to the partial damages observed forB. subtilis. The damaged cells of both bacterial species also exhibited leakage of intercellular compounds such as DNA, proteins and polysaccharides. This loss of intracellular macromolecules resulted in increased cell surface roughness and decreased cell diameter and elasticity, irrespective of the bacterial species tested. The results demonstrated that the degree of cell damage inflicted by HPJD treatment is dependent on the cell wall and membrane structure of the bacterial species. In summary, we propose multiple possible mechanisms of cell disruption resulting from HPJD treatment.