Feeding of a Freshwater Flagellate, Bodo saltans, on Diverse Bacteria¹

Abstract

Bodo saltans was isolated from a chalk stream and fed with pure cultures of seven bacteria obtained from the same river. The flagellates were allowed to migrate into suspensions of either of two bacterial species in a T‐maze at 20–22°C. There was a significant difference (P < 0.01) between the numbers of flagellates which migrated into suspensions of different bacteria, which were subsequently arranged in an order of “attractiveness” to the flagellate. Bodo saltans grew successfully in monoxenic suspensions of all seven bacterial strains, but more rapid growth occurred with non‐flagellated than with flagellated bacteria; this may be because while feeding, B. saltans tends to associate with surfaces where non‐flagellated bacteria may also congregate. The efficiency with which B. saltans is able to utilize different bacteria may be influenced by the motility or secretory activities of the bacteria. There was no incontrovertible evidence that B. saltans responds to specific bacterial attractants.

Prey-size dependency of grazing by free-living marine flagellates

“…Chemosensory behavior has been shown to exist among some flagellates exposed to gradients of dissolved compounds or bacterial numbers (e.g. Sibbald et al 1987, Bennett et al 1988, Mitchell et al 1988. However, it is not certain whether these chemosensory behaviors are significant to grazing in the natural environment because they depend on the magnitude and persistence of gradients and this is not well known.…”

Massisteria marina Larsen &amp;amp;amp;amp;amp;amp;amp;amp;amp; Patterson 1990, a widespread and abundant bacterivorous protist associated with marine detritus

“…Bacteria attached to the detritus are not accessible by filter-feeding (Fenchel 1986b) and are targets for the remaining 2 groups. The third type of flagellate includes the raptorial feeders (or 'nibblers') which consume individual bacteria associated with the accessible surfaces of detritus (Fenchel 1982, 1986a, Caron 1987, Mitchell et al 1988, Patterson et al 1989. So far there have been no descriptions of flagellates specifically adapted to the fourth way -feeding on bacteria within the detritus.…”

Molecular comparison of cultivable protozoa from a pristine and a polycyclic aromatic hydrocarbon polluted site

“…Cultivationdependent approaches may be hampered by different factors. Some protozoa do not survive the technical procedures associated with dilution techniques (Ekelund and Patterson, 1997), and some appear to be unable to grow on the bacterial food source offered in the microtiter plates (Severtsova, 1928;Mitchell et al, 1988;Boenigk and Arndt, 2002), or need an agar substrate for optimal growth. In addition, the condition of an homogeneous mixing of the soil suspension is hardly met (Berthold and Palzenberger, 1995).…”