FIG. 7.
Results of the predation chemostat experiment performed to determine the influence of grazing by the bacterivorous flagellate Ochromonas sp. strain DS on the morphology of F. major. Bacteria were grown in two parallel reactors, reactor 1 (solid symbols) and reactor 2 (open symbols), at the same growth rate, 0.5 day−1. Both reactors were inoculated on day 11 with the flagellate, and on day 31 flagellates were eliminated from both reactors by treatment with specific inhibitors (cycloheximide and colchicine). In the period between introduction and elimination of flagellates, the predators established populations (data not shown) comparable to the populations in other chemostat experiments. (A) Influence of flagellate grazing on bacterial numbers. (B) Influence of flagellate grazing on the percentage of long filaments (length, >10 μm) in the population. (C) Influence of flagellate grazing on the mean length of bacteria (including single cells and filaments). d, days.