Simultaneous predatory and prey-independent growth by B. bacteriovorus Tiberius. (a) Plaques formed by lysis of prey within lawns of prey cells by B. bacteriovorus(i) HD100 clear plaque and (ii) Tiberius plaque with central colony growth. (b) Light microscopy images of serpentine prey-independently growing Tiberius cells alongside free-swimming Bdellovibrio cells and bdelloplasts. (c) Electron microscopy of Tiberius cells (i & ii) attack phase, predatory cells (iii-v) filamentous, prey-independently growing cells from the same samples as in (i & ii). (d – f) Timelapse microscopy still images (from all T= timepoint in minutes from addition of bdellovibrios to slide) from movies showing: (d) co-existence of long HI prey-independently growing cells (black arrows) and comma-shaped predatory B. bacteriovorus Tiberius invading an E. coli prey cell (white arrow); (e) evidence that the outcome of prey entry by B. bacteriovorus Tiberius results in bdellovibrio replication- one cell enters at T=0 and three leave upon prey lysis at T=300; (f) septation by binary fission of the long prey-independently growing form of B. bacteriovorus Tiberius. (g) Diagram comparing the modes of growth of B. bacteriovorus HD100 and Tiberius in both high and low nutrient conditions, showing simultaneous predatory and prey-independent growth by Tiberius in low nutrient conditions. (h) Cell pellets of predatory cells showing the white cells of B. bacteriovorus Tiberius against the yellow, carotenoid-producing, cells of strain HD100.
Hobley et al. BMC Genomics 2012 13:670 doi:10.1186/1471-2164-13-670