Nondestructive methods for removal of bacteria from silicate surfaces
Nondestructive methods for removal of bacteria from silicate surfaces
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DOI：
10.1080/01490450303888
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发表时间：
2003-01-01
影响因子：
2.3
通讯作者：
Liermann, LJ
中科院分区：
文献类型：
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作者：
Buss, HL;Brantley, SL;Liermann, LJ
为了研究记录微生物群对矿物表面影响的生物特征，必须在不以化学或物理方式改变表面的情况下去除微生物物质。在之前的扫描电子显微镜（SEM）分析工作中，我们用溶菌酶从硅酸盐表面去除了土壤细菌：然而，当用原子力显微镜（AFM）在纳米尺度上分析溶菌酶处理的表面时，观察到残留物质。因此，我们测试了五种方法的除菌效果，包括四种不同的清洁剂和二氧化碳除雪。 AFM 观察显示，在芽孢杆菌生长 13 天后，经过 CO2 雪清洗的玻璃表面有残留物。 （土壤微生物）。相比之下，用丙酮允许的四种洗涤剂中的每一种进行处理完全去除了芽孢杆菌属。即使在生长 77 天后也不会改变表面的形貌。然而，对玻璃表面上部 25 埃的 X 射线光电子能谱 (XPS) 分析显示，某些清洁剂会发生化学变化，但十二烷基硫酸钠 (SDS) 不会发生化学变化。因此，对于严格的形貌分析（例如 AFM），所测试的四种去污剂中的任何一种都可以被视为去除细菌的可行选择，但对于表面化学分析，建议使用 pH 中性的阴离子去污剂 SDS。此外，洗涤剂处理后的 AFM 成像显示，暴露于细菌的玻璃表面上存在蚀刻坑，这些蚀刻坑的大小和分布与芽孢杆菌属的小菌落相似。通过 XPS 测量，相对于 Si，这些表面的 Fe 和 Al 也有所减少，但在不含细菌的培养基中培养的类似对照显示出 Fe 和 Al 没有减少。
In order to study biosignatures documenting the effects of microbiota on mineral surfaces, microbial matter must be removed without chemically or physically changing the surface. In previous work for analysis by scanning electron microscopy (SEM) we removed soil bacteria,from silicate surfaces with lysozyme: however, when lysozyme-treated surfaces were analyzed at nanoscale by atomic force microscopy (AFM), residual matter was observed. Therefore, we tested removal of bacteria by each of five methods, including four different detergents and CO2 snow cleaning. AFM observations revealed residue on glass surfaces that underwent CO2 snow cleaning after 13 days of growth of Bacillus sp. (a soil microbe). In contrast, treatment with each of four detergents allowed by acetone completely removed Bacillus sp. without altering the topography of the surfaces even after 77 days of growth. However, X-ray photoelectron spectroscopic (XPS) analyses of the upper 25 Angstrom of the glass surfaces revealed chemical alterations by some detergents, but not by the detergent sodium dodecyl sulfate (SDS). Therefore, for strictly topographic analyses such as AFM, any of the four detergents tested can be considered a viable option for bacterial removal, but for analyses of surface chemistry, the pH-neutral, anionic detergent SDS is recommended. Additionally, AFM imaging after detergent treatments revealed etch pits on glass surfaces exposed to bacteria that were similar in size and distribution to small colonies of Bacillus sp. These surfaces were also depleted in Fe and Al relative to Si as measured by XPS, yet similar controls incubated in media without bacteria showed no depletion in Fe and Al.