Use of biolumescent bacteria, Xenorhabdus luminescens, to measure predation on bacteria by freshwater microflagellates

Dianne B. Seale, Martin E. Boraas, Dale Holen, Kenneth H. Nealson

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Ligh emitted by the bioluminescent bacterium, Xenorhabdus luminescens (isolated from a nematode host), can be measured to monitor reductions of these bacteria in the presence of phagotrophs. X. luminescens is relatively large (0.6 ¢ 3 μm), but comparable in size to many cyanobacteria. We used the light emission method to examine phagotroph feeding on X. luminescens using uni-specific cultures of two chrysomonads, Ochromonas sp. and Spulemma sp. From light decay rates in control and experimental vials, we computed an apparent filtration rate (FR); then, for a concentration (C) of 1 · 106 bacteria ml-1, we estimated capture rate (CR) as FR · C. The Ochromonas sp. did not ingest the bacterium. The maximum estimated FR for Spumella, observed at 6.0 · 103 flagellates ml-1 (medium density), was 0.37 ml h-1, for a volume-specific clearance rate (FR/cell volume) of 7.9 · 105 h-1 and a CR of 62 bacteria · flagellate-1 h-1. Video microscopy indicated these were accurate estimates of capture rates. Microscopic counts were used to monitor growth of a flagellate, Spumella sp., on X. luminescens as the sole food supply. The flagellate doulbed in number every 3.2, while consuming bacteria at a rate of 23 bacteria flagellate-1 h-1. The Spumella grazed the bacteria to a minimum of 5 · 105 cells ml-1, a concentration comparable to observed field densities of other bacteria.

Original languageEnglish (US)
Pages (from-to)31-39
Number of pages9
JournalFEMS Microbiology Letters
Volume73
Issue number1
DOIs
StatePublished - Jan 1990

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Photorhabdus
Fresh Water
Bacteria
Ochromonas
Light
Video Microscopy
Food Supply
Cyanobacteria
Cell Size

All Science Journal Classification (ASJC) codes

  • Microbiology
  • Molecular Biology
  • Genetics

Cite this

@article{4142b2c966944400b2490c9e78350573,
title = "Use of biolumescent bacteria, Xenorhabdus luminescens, to measure predation on bacteria by freshwater microflagellates",
abstract = "Ligh emitted by the bioluminescent bacterium, Xenorhabdus luminescens (isolated from a nematode host), can be measured to monitor reductions of these bacteria in the presence of phagotrophs. X. luminescens is relatively large (0.6 ¢ 3 μm), but comparable in size to many cyanobacteria. We used the light emission method to examine phagotroph feeding on X. luminescens using uni-specific cultures of two chrysomonads, Ochromonas sp. and Spulemma sp. From light decay rates in control and experimental vials, we computed an apparent filtration rate (FR); then, for a concentration (C) of 1 · 106 bacteria ml-1, we estimated capture rate (CR) as FR · C. The Ochromonas sp. did not ingest the bacterium. The maximum estimated FR for Spumella, observed at 6.0 · 103 flagellates ml-1 (medium density), was 0.37 ml h-1, for a volume-specific clearance rate (FR/cell volume) of 7.9 · 105 h-1 and a CR of 62 bacteria · flagellate-1 h-1. Video microscopy indicated these were accurate estimates of capture rates. Microscopic counts were used to monitor growth of a flagellate, Spumella sp., on X. luminescens as the sole food supply. The flagellate doulbed in number every 3.2, while consuming bacteria at a rate of 23 bacteria flagellate-1 h-1. The Spumella grazed the bacteria to a minimum of 5 · 105 cells ml-1, a concentration comparable to observed field densities of other bacteria.",
author = "Seale, {Dianne B.} and Boraas, {Martin E.} and Dale Holen and Nealson, {Kenneth H.}",
year = "1990",
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Use of biolumescent bacteria, Xenorhabdus luminescens, to measure predation on bacteria by freshwater microflagellates. / Seale, Dianne B.; Boraas, Martin E.; Holen, Dale; Nealson, Kenneth H.

In: FEMS Microbiology Letters, Vol. 73, No. 1, 01.1990, p. 31-39.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Use of biolumescent bacteria, Xenorhabdus luminescens, to measure predation on bacteria by freshwater microflagellates

AU - Seale, Dianne B.

AU - Boraas, Martin E.

AU - Holen, Dale

AU - Nealson, Kenneth H.

PY - 1990/1

Y1 - 1990/1

N2 - Ligh emitted by the bioluminescent bacterium, Xenorhabdus luminescens (isolated from a nematode host), can be measured to monitor reductions of these bacteria in the presence of phagotrophs. X. luminescens is relatively large (0.6 ¢ 3 μm), but comparable in size to many cyanobacteria. We used the light emission method to examine phagotroph feeding on X. luminescens using uni-specific cultures of two chrysomonads, Ochromonas sp. and Spulemma sp. From light decay rates in control and experimental vials, we computed an apparent filtration rate (FR); then, for a concentration (C) of 1 · 106 bacteria ml-1, we estimated capture rate (CR) as FR · C. The Ochromonas sp. did not ingest the bacterium. The maximum estimated FR for Spumella, observed at 6.0 · 103 flagellates ml-1 (medium density), was 0.37 ml h-1, for a volume-specific clearance rate (FR/cell volume) of 7.9 · 105 h-1 and a CR of 62 bacteria · flagellate-1 h-1. Video microscopy indicated these were accurate estimates of capture rates. Microscopic counts were used to monitor growth of a flagellate, Spumella sp., on X. luminescens as the sole food supply. The flagellate doulbed in number every 3.2, while consuming bacteria at a rate of 23 bacteria flagellate-1 h-1. The Spumella grazed the bacteria to a minimum of 5 · 105 cells ml-1, a concentration comparable to observed field densities of other bacteria.

AB - Ligh emitted by the bioluminescent bacterium, Xenorhabdus luminescens (isolated from a nematode host), can be measured to monitor reductions of these bacteria in the presence of phagotrophs. X. luminescens is relatively large (0.6 ¢ 3 μm), but comparable in size to many cyanobacteria. We used the light emission method to examine phagotroph feeding on X. luminescens using uni-specific cultures of two chrysomonads, Ochromonas sp. and Spulemma sp. From light decay rates in control and experimental vials, we computed an apparent filtration rate (FR); then, for a concentration (C) of 1 · 106 bacteria ml-1, we estimated capture rate (CR) as FR · C. The Ochromonas sp. did not ingest the bacterium. The maximum estimated FR for Spumella, observed at 6.0 · 103 flagellates ml-1 (medium density), was 0.37 ml h-1, for a volume-specific clearance rate (FR/cell volume) of 7.9 · 105 h-1 and a CR of 62 bacteria · flagellate-1 h-1. Video microscopy indicated these were accurate estimates of capture rates. Microscopic counts were used to monitor growth of a flagellate, Spumella sp., on X. luminescens as the sole food supply. The flagellate doulbed in number every 3.2, while consuming bacteria at a rate of 23 bacteria flagellate-1 h-1. The Spumella grazed the bacteria to a minimum of 5 · 105 cells ml-1, a concentration comparable to observed field densities of other bacteria.

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JO - FEMS Microbiology Letters

JF - FEMS Microbiology Letters

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