Predation of cyanobacteria by protozoa

Dryden, Robert Cumming; Wright, S. J. L.

doi:10.1139/m87-080

Cited by 54 publications

(38 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Grazing by higher trophic level organisms appears to be a major contributor to the loss of Microcystis blooms (Dryden & Wright 1987). Many organisms graze on Microcystis spp., including fish (Miura 1990, Northcott et al 1991, zooplankton (Hanazato & Yasuno 1984) and protists (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Grazing and growth of the heterotrophic flagellate Diphylleia rotans on the cyanobacterium Microcystis aeruginosa

Kim¹,

Nakano²,

Kim³

et al. 2006

Aquat. Microb. Ecol.

View full text Add to dashboard Cite

) by D. rotans were observed when they were fed the most toxic of the 5 Microcystis strains, M. aeruginosa NIER-10001. These results suggest that D. rotans has a high tolerance to M. aeruginosa and may undergo microcystin-mediated growth.KEY WORDS: Algivores · Heterotrophic flagellates · Diphylleia rotans · Microcystis spp. · Microcystin-mediated growth · Ingestion Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 45: [163][164][165][166][167][168][169][170] 2006 examined the ecophysiology of this flagellate on its prey using comparisons of grazing behavior on toxic and non-toxic Microcystis strains, along with other algal strains, which represent different food types and qualities. MATERIALS AND METHODSIsolation and culture of the heterotrophic flagellate. Furuike Pond (33°49' 21'' N, 132°48' 04'' E; altitude 40 m) is an impoundment located in Sancho, Matsuyama City, Ehime Prefecture, Japan. It has a surface area of 7400 m 2 and a maximum depth of 1.5 m. The pond is hypereutrophic due to anthropogenic loading from the watershed (Nakano et al. 2001b) and is heavily populated by cyanobacteria, such as Microcystis aeruginosa and M. wesenbergii, from early summer to fall each year (Manage et al. 1999).For isolation of a flagellate capable of grazing on Microcystis species, Microcystis aeruginosa NIES-298 was incubated in Cytophaga broth (CB) medium (MCC-NIES; www.nies.go.jp/biology/mcc/home_j.htm) and mixed with a pond water sample that had been filtered through a Nitex net (mesh size, 154 µm) for removal of larger zooplankton. This mixture was incubated at 25°C in the dark for 3 to 4 d. Flagellates were isolated using a Pasteur micropipette under a light microscope. We established a monoclonal flagellate culture using a repetitive serial isolation process consisting of enrichment, dilution and single cell isolation steps. The isolated flagellate was maintained using a commercial strain of Chlorella TM (Aquanet) as prey. Water was collected from the Pal'tang Reservoir, Korea, filtered through a Whatman GF/F filter and sterilized in an autoclave to yield filtered sterilized water (FSW). A quantity of Chlorella TM was suspended in the FSW, and the flagellate was inoculated into the Chlorella TM suspension. We maintained the flagellate strain by inoculating it weekly into new Chlorella TM suspensions. Incubations were performed at 25°C under a light intensity of 40 to 45 µE m -2 s -1 of cool white fluorescent light, with a 12:12 h light:dark photoperiod.To identify the flagellate, we used light and epifluorescence microscopy and 18S rDNA sequencing. Morphological observations, including the presence of 2 long apical and equal flagella inserting near the anterior end at the top of the ventral groove formed by the curving lateral margins of the cell, a cell dimension of 15 × 20 µm (subject to change during feeding), and feeding observations such as free movement or rotation during feeding via the ventral groove, identified the flagellate as Diphylleia rotans (Massart 1920...

show abstract

Section: Introductionmentioning

confidence: 99%

“…Many organisms graze on Microcystis spp., including fish (Miura 1990, Northcott et al 1991, zooplankton (Hanazato & Yasuno 1984) and protists (e.g. Dryden & Wright 1987). Among these, the highly abundant protists may be the most important grazers of Microcystis spp.…”

Section: Introductionmentioning

confidence: 99%

Grazing and growth of the heterotrophic flagellate Diphylleia rotans on the cyanobacterium Microcystis aeruginosa

Kim¹,

Nakano²,

Kim³

et al. 2006

Aquat. Microb. Ecol.

View full text Add to dashboard Cite

show abstract

“…In their natural environments, cyanobacteria are subjected to grazing pressure by a variety of organisms, including protistan predators such as ciliates, flagellates, and amoebae (7). Grazing affects both mortality and population structure (8), as has recently been observed in the rapid decline of biomass of Microcystis in a natural pond and in the restructuring of the bloom with a shift from a susceptible Microcystis species to a resistant one upon amoebal grazing (9).…”

mentioning

confidence: 99%

Impairment of O-antigen production confers resistance to grazing in a model amoeba–cyanobacterium predator–prey system

Simkovsky

Daniels

Tang³

et al. 2012

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

View full text Add to dashboard Cite

The grazing activity of predators on photosynthetic organisms is a major mechanism of mortality and population restructuring in natural environments. Grazing is also one of the primary difficulties in growing cyanobacteria and other microalgae in large, open ponds for the production of biofuels, as contaminants destroy valuable biomass and prevent stable, continuous production of biofuel crops. To address this problem, we have isolated a heterolobosean amoeba, HGG1, that grazes upon unicellular and filamentous freshwater cyanobacterial species. We have established a model predator–prey system using this amoeba and Synechococcus elongatus PCC 7942. Application of amoebae to a library of mutants of S. elongatus led to the identification of a grazer-resistant knockout mutant of the wzm ABC O-antigen transporter gene, SynPCC7942_1126. Mutations in three other genes involved in O-antigen synthesis and transport also prevented the expression of O-antigen and conferred resistance to HGG1. Complementation of these rough mutants returned O-antigen expression and susceptibility to amoebae. Rough mutants are easily identifiable by appearance, are capable of autoflocculation, and do not display growth defects under standard laboratory growth conditions, all of which are desired traits for a biofuel production strain. Thus, preventing the production of O-antigen is a pathway for producing resistance to grazing by certain amoebae.

show abstract

“…Reports of amoebae predation on cyanobacteria have mainly concerned to laboratory investigations with cultures (13,18,(26)(27)(28)(29), while studies based on natural communities are uncommon (20,23). This is specially true for soil habitats and very shallow freshwaters, where however the overall amount of amoebae and cyanobacteria (mainly filamentous species) are usually high (8). Although Thecamoeba sphaeronucleolus Greeff (Lobosea, Amo-ebida) is a species frequently found in soil and in sediment of freshwaters (14), it has been scarcely studied (10,11,14,24).…”

mentioning

confidence: 99%

selective predation of Thecamoeba sphaeronucleolus (Greeff, 1891) on filamentous algae in natural conditions.

Bécares¹,

Romo²

1994

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

Predation of cyanobacteria by protozoa

Cited by 54 publications

References 35 publications

Grazing and growth of the heterotrophic flagellate Diphylleia rotans on the cyanobacterium Microcystis aeruginosa

Grazing and growth of the heterotrophic flagellate Diphylleia rotans on the cyanobacterium Microcystis aeruginosa

Impairment of O-antigen production confers resistance to grazing in a model amoeba–cyanobacterium predator–prey system

selective predation of Thecamoeba sphaeronucleolus (Greeff, 1891) on filamentous algae in natural conditions.

Contact Info

Product

Resources

About