Enumeration and abundance of mycophagous protozoa in soil, with special emphasis on heterotrophic flagellates

Mycophagous protozoa occur in most soils, but data on their quantitative importance are sparse, possibly due to a lack of suitable counting techniques. I describe a modification of the most probable number method for enumeration of mycophagous protozoa, especially flagellates, with indigenous soil fungi and yeasts as their food source in large individual wells in 24-well microtitre plates. About 103 mycophagous flagellates g−1 dry soil were present in all soils examined. Mycophagous flagellates responded by a 4-fold increase in a week after addition of glucose to soil. Their abundance and quick response to environmental changes suggest an important role for mycophagous flagellates in determining the size of populations of yeast cells and fungal conidia in soil.