Abstract
A scanning electron microscopic (SEM) image analysis system was used to measure bacterial biovolume in fresh water. Halation, which is a problem encountered in epifluorescence microscopy, is avoided in SEM image analysis. The biovolume-to-carbon and nitrogen conversion factors, which are used to estimate bacterial biomass, were determined in four standard strains and five river water isolates. These factors for carbon and nitrogen were 0.34±0.06pg C/μm3 and 0.094±0.014pg N/μm3 respectively. There was no noticeable difference among bacterial species or growth phases. Bacterial size and biomass were measured in polluted and unpolluted river water. The average volume of bacterial cell was twice as high in polluted water, while the bacterial biomass was 35 times higher than in unpolluted water.
