Microorganisms of Groundwater and Decomposing Refuse as Viewed by the Transmission Electron Microscope

The chief problem in obtaining an objective view of native microbial communities is lack of suitable experimental techniques. In our laboratory a simple preparative method was used in order to make electron microscopical investigations of indigenous microorganisms from ground-water and decomposing municipal refuse possible. This method includes (i) suspension of the complex microflora from the refuse sample in a buffered water solution or a direct use of groundwater samples; (ii) embedding of microorganisms from the suspension on the surface of collodion filmed and carbon coated electron microscopical grids by direct centrifugation in the Beckman Airfuge; (iii) a one step staining with 1,5% phosphotungstic acid at pH 6.8 in centrifuge rotor chambers. The main advantage of our method is based on a supporting effect of the centrifugal force towards the concentration and adhesion of microbial cells at the surface of electron microscopical grids. Electron microphotographs of microorganisms from ground-water, and decomposing municipal refuse are presented.