Bdellovibrio host dependence: the search for signal molecules and genes that regulate the intraperiplasmic growth cycle

Thomashow, Michael F.; Cotter, T W

doi:10.1128/jb.174.18.5767-5771.1992

Cited by 45 publications

(40 citation statements)

References 25 publications

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“…However, we were unable to replicate these results. Follow-up studies found that although prey extracts sustained extracellular filamentous growth and DNA replication, they could not promote the differentiation of the nonreproductive AP cell to the GP (32)(33)(34)(35). This result suggested that two separate prey-derived cues, one in the soluble prey extract fraction and the other hitherto undefined, were necessary for the AP-to-GP transition to occur (33).…”

Section: Discussionmentioning

confidence: 94%

“…Type I HI mutants arise at low frequency (10 −7 ) and can grow saprophytically in the presence of prey extract (32,37). To confirm that prey extract-dependent ex vivo growth did not result from the selection of HI mutants but was still seen in WT cells, DNA was purified from AP cells and from ex vivo-cultivated GP cells.…”

Section: Resultsmentioning

confidence: 99%

“…S1). Mutations in gene bd0108 yield type I HI mutants that grow in the absence of prey in a rich medium supplemented with prey extract, i.e., they require the second cue (32,36,37). Type II HI mutants eliminate the requirement for prey extract; they are generated by a mutation in rhlB or in pcnB, genes that encode for RNA degradosome subunits (37).…”

Section: Significancementioning

confidence: 99%

“…One cue presumably elicits the predatory process, promoting prey penetration, bdelloplast formation, and prey consumption (32,33). A second soluble cue promotes DNA synthesis and is required for sustained cellular growth (33)(34)(35).…”

Section: Significancementioning

confidence: 99%

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Cell-cycle progress in obligate predatory bacteria is dependent upon sequential sensing of prey recognition and prey quality cues

Rotem

Pasternak

Shimoni

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Predators feed on prey to acquire the nutrients necessary to sustain their survival, growth, and replication. In Bdellovibrio bacteriovorus, an obligate predator of Gram-negative bacteria, cell growth and replication are tied to a shift from a motile, free-living phase of search and attack to a sessile, intracellular phase of growth and replication during which a single prey cell is consumed. Engagement and sustenance of growth are achieved through the sensing of two unidentified prey-derived cues. We developed a novel ex vivo cultivation system for B. bacteriovorus composed of prey ghost cells that are recognized and invaded by the predator. By manipulating their content, we demonstrated that an early cue is located in the prey envelope and a late cue is found within the prey soluble fraction. These spatially and temporally separated cues elicit discrete and combinatory regulatory effects on gene transcription. Together, they delimit a poorly characterized transitory phase between the attack phase and the growth phase, during which the bdelloplast (the invaded prey cell) is constructed. This transitory phase constitutes a checkpoint in which the late cue presumably acts as a determinant of the prey's nutritional value before the predator commits. These regulatory adaptations to a unique bacterial lifestyle have not been reported previously.microbial ecology | bacterial physiology | bacterial cell cycle | predatory bacteria | Bdellovibrio bacteriovorus

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Section: Discussionmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Section: Significancementioning

confidence: 99%

Section: Significancementioning

confidence: 99%

See 2 more Smart Citations

Cell-cycle progress in obligate predatory bacteria is dependent upon sequential sensing of prey recognition and prey quality cues

Rotem

Pasternak

Shimoni

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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“…Several different types of bacterial predator-prey interactions have been reported these habitats. Bacteria such as Bdellovibrio (Burnham et al, 1968;Sockett, 2009;Thomashow & Cotter, 1992) and Daptobacter (Guerrero et al, 1986), which are obligate predators, penetrate the cell wall of the bacterial prey and grow within the periplasm or cytoplasm. Not all microbes kill their prey by penetrating the cell.…”

Section: Introductionmentioning

confidence: 99%

Calcium is required for ixotrophy of Aureispira sp. CCB-QB1

2015

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Ixotrophy is a process that enables certain microbes to prey on other cells. The ability of cells to aggregate or adhere is thought to be a significant initial step in ixotrophy. The gliding, multicellular filamentous bacterium Aureispira sp. CCB-QB1 belongs to the family Saprospiraceae and preys on bacteria such as Vibrio sp. in seawater. Adhesion and cell aggregation were coincident with preying and were hypothesized to play an important role in the ixotrophy in this bacterium. To test this hypothesis, experiments to elucidate the mechanisms of aggregation or adhesion in this bacterium were performed. The ability of Aureispira QB1 to adhere and aggregate to prey bacterium, Vibrio sp., required divalent cations, especially calcium ions. In the presence of calcium, Aureispira QB1 cells captured 99 % of Vibrio sp. cells after 60 min of incubation. Toluidine blue O, which binds acidic polysaccharides, bound to Aureispira QB1 and inhibited adhesion of Aureispira QB1. These results suggest that acidic polysaccharides are needed for aggregation or adhesion of Aureispira and that calcium ions play a significant role in these phenomena.

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Bdellovibrio

Williams¹,

Baer²,

Tudor³

2015

Bergey's Manual of Systematics of Archaea and Bacteria

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Bdel.lo.vib' ri.o . Gr. n. bdella leech, sucker; M.L. masc. n. Vibrio a generic name; M.L. n. Bdellovibrio a leechlike vibrio. Proteobacteria / Deltaproteobacteria / Bdellovibrionales / Bdellovibrionaceae / Bdellovibrio Vibrios, 0.20–0.4 × 0.5–1.4 μm. Motile by a single, polar, sheathed flagellum . Gram negative. Prey upon Gram‐negative bacteria. Have a predatory lifestyle characterized by two distinct phases, a free‐living attack phase and an intraperiplasmic growth phase (Figure 1). Prey‐independent mutants that have lost their requirement for prey cells occur spontaneously and can be isolated in the laboratory. Some of these prey‐independent mutants retain the ability to grow predaciously and are considered to be facultative with respect to their requirement for prey cells. Aerobic , having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Contain cytochromes a, c , and b . Mesophilic. Oxidase positive . Catalase variable. Occur in fresh and salt water, soil, and sewage. The mol % G + C of the DNA is : 49.5–51 (Torrella et al., 1978). Type species : Bdellovibrio bacteriovorus Stolp and Starr 1963, 243.

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Bdellovibrio host dependence: the search for signal molecules and genes that regulate the intraperiplasmic growth cycle

Cited by 45 publications

References 25 publications

Cell-cycle progress in obligate predatory bacteria is dependent upon sequential sensing of prey recognition and prey quality cues

Cell-cycle progress in obligate predatory bacteria is dependent upon sequential sensing of prey recognition and prey quality cues

Calcium is required for ixotrophy of Aureispira sp. CCB-QB1

Bdellovibrio

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