Abstract
Trace metals play an important role in methanogens growth and methane formation. In order to understand the requirement of trace metals for methanogens, the accurate measurement of intracellular trace metals of methanogens was required.
In this study, the washing effects of distilled water, physiological salt solution, phosphate buffer and EDTA mixture liquid on elimination of trace metals outside methanogen cells was investigated. Washed cells were pretreated by wet digestion method, and the content of trace metals were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The variation in the content of intracellular ion measured was the smallest when phosphate buffer solution was used.
Damage of cells was observed by scanning probe microscopy. Furthermore, the damage of cells was relatively larger when cells were washed with distilled water. Because the washing process might cause the collapse of cells, we fixed the cell using glutaraldehyde before cell was washed. As a result, the fixation of cell was showed to be an effective method to reduce the measurement error in the analysis of intracellular trace metals.