• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.209-213
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• 2012

Members of the ciliate group of protozoans are often observed in mass cultures of rotifers. In particular, Euplotes and Vorticella are common contaminating species. In this study, I examined the effect of the ciliates Euplotes sp. and Vorticella sp. on the growth of the rotifer Brachionus rotundiformis by conducting inter-specific and tripartite-specific mixed-culture experiments. The growth of rotifers was suppressed in co-existence with Euplotes sp. compared with monocultures of rotifers. However, Vorticella sp. promoted rotifer growth. Moreover, Vorticella sp. improved the growth of rotifers suppressed by Euplotes sp. contaminants. In 5-L semi-mass cultures of rotifers, growth of the contaminating protozoan Euplotes sp. was heavily suppressed by Vorticella sp. The stable maintenance of the rotifer culture ecosystem can be achieved by manipulating the types of contaminating protozoan species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.317-319
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• 1999

The ciliate, Vorticella was often observed in the rotifer mass culture tanks as common co-existing organism. This Vorticella performed as a predator for aquatic bacteria population in the rotifer mass culture tanks. This study was carried out to investigate a cyst formation medium of Vorticella in the laboratory for keeping Vorticella seed. The test organism Vorticella sp. was isolated from culture water of rotifer mass culture tanks. The cyst of Vorticella was formed by dried-method for the formation and maintainance of cyst. MCCF (Marine Ciliate Cyst Formation) medium was used for cyst formation (incystment), preservation and return to moving cell (excystment) of the marine ciliate, Vorticella sp. The cyst shape and size were ellipical type and $30.51 \pm1.98\;\mu$m (Avg. $\pm$ SD) of minor axis and $28.89 \pm2.12\;\mu$m (Avg. $\pm$ SD) of minor axis (n=10), The Vorticella cyst was kept in the room temperature ($10\~35^{\circ}C$) and total dark condition (24D:0L) during 1 year. The preserved cyst was transferred to moving cell state (excystment) only by the addition of fresh sea water in the MCCF medium. The five Vorticella sp. moving cells of excysted from cysts showed the growth up to 912$\pm$64 cells/10 ml in MCCF medium during the culture period of 16 days. This MCCF medium was very useful tool for cyst formation and species preservation of marine ciliate Vorticella.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.45-52
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• 1999

This study was conducted to evaluate the effects of microbial inoculation on sewage sludge composting. The number and species of microorganisms in sewage sludge sampled on February were higher than those sampled on August. The composting of sewage sludge is inhibited by the polyacrylamide cation, which was used as a coagulant and known to repress the growth of microorganisms. The growth of all microorganisms was inhibited by the addition of the polyacrylamide cation at a concentration of more than 0.8%. The species and viable counts of microorganisms were observed to increase during composting sewage sludge by inoculation of the effective microorganisms and addition of the pine tree sawdust as a bulking agent, compared with those without inoculation. A variety of organisms in compost(sewage sludge plus sawdust) were observed after composting for 30 days, such as Fragilaria sp., Proales sp., Vorticella sp., Schizothrix sp., Anabaena sp., Zoothaminium sp., Epstylis sp., Arcella sp., Balantidium sp., Actinophrys sp., Synedra sp., Euglypha sp., Ulothrix sp., Anacystis sp., and Clostium sp.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.149-179
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• 2004

In order to understand the taxonomic and ecologic characteristics on ciliates plankton, surface water samples were collected once a weekly from March 2001 to December 2001 except once a monthly from December 2001 to January 2001 and twice a monttdy at February 2001 at Pal'tang reservoir in Korea. Totally 12 species belonging to 10 genera in 7 families of 6 order, were identified and all species new record in Korea. All of them had been recorded in eutrophic water bodies. Succession of dominant species occurred obviously according to seasonality. Large -sized Codonella cratera, Rimostrombidium lacustris, Strobilidium caudatum, Limnostrombidium viride, Pelagostrombidium fallax, Stylonychia sp., Pseudostrombidium plaktonticum and Phascolodon vorticella dominated during the period of outbreak of nanophytoplankton in winter to spring. However, small-sized Rimostrombidium hyalinum, rimostrombidium brachykinetum, Halteria gradinella and Vorticella convallaria occurred when the bacteria abundance increased in summer to autumn.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.379-383
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• 1988

To evaluate the treatability of activated sludge induced by benzene with microorganisms, isolation and characterization of benzene-degrading microorganisms were carried out. Six bacterial isolates from the activated sludge were identified ; Pseudomonas fluorescens, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Klebsiella pneumoniae. P. fluorescens degraded 55% of benzene contained in the medium as a sole carbon source, E. cloacae 24%, E. agglomerans 41%, and K. oxytoca 32%. Optimal temperature, pH and benzene concentration for growth of P. fluorescens appeared to be 31$^{\circ}C$, pH 7.0, and 300mg benzene per liter. When the P. fluorescens was dominant in the activated sludge induced by benzene, the indicator protozoa was Aspidisca sp. When concentration of benzene was about 387mg per liter, the growths of Aspidisca sp. and Litonotus sp. were high. Protozoa, Litonotus sp. and Vorticella sp. did not grow over 1600mg of benzene per liter.

• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.11-18
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• 2008

Seasonal succession and community composition of planktonic ciliates were studied in Kyungan Stream from December 2000 to December 2001. Oligotrichs accounted for 53% of total ciliates. Total abundance of ciliates peaked in spring (30 March, 6 April) and in summer (8 June, 20 July) reaching values up to $1.9\times10^4$ cells $L^{-1}$. Seasonal succession of dominant species occurred obviously. Large-sized $(>50{\mu}m)$ species (Stylonychia sp1, Phascolodon vorticella and Codonella cratera) dominanted from winter to spring. Small sized $(<30{\mu}m)$ species (Vorticella spp., Rimostrombidium hyalinum and Halteria grandinella) dominanted in summer and autumn. Total abundance of large-sized species coincided with the Chl-${\alpha}$ concencetation during the study (r=0.33, p<0.05, n=39). Among the small-sized species Halteria grandinella was a significant relationship with bacterial abundance (r=0.35, p<0.05, n=39).

• Journal of fish pathology
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• v.3 no.2
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• pp.51-60
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• 1990

Parasites of freshwater fishes in Cheju-do were studied from May 1989 to April 1990, and incidence of infection in 16 fish species was reported. Protozoan parasites (Trichodina sp., Chilodonella sp., Ichthyophthirius sp., Vorticella sp., Myxidium sp., Myxobolus sp., Henneguya sp:, Ichthyobodo sp., and Trychophrya sp.), water mold (Saproregnia sp.), two monogenes (Dactylogyrus sp. and Gyrodactylogyrus sp.), Trematods, Cestods, Nematods, Acanthocephalas, parasitic copepods(Lernaea sp. and Pseudergasilus sp.) and a Hirudinea were recognized as freshwater fish parasites in Cheju-do. Trichodina sp. showed the highest infection rate (18.3%). Fifty seven individual fishes out of 311 were infected by this parasite. Nematods showed the second highest infection rate (13.5%). Dactylogyrus sp., Acanthocephalas, and Trematods showed the third (4.8%), fourth (4.2%), and fifth (2.6%) infection rate respectively. Of the 16 fish species Cryptocentrus filifer (Gobiidae) showed the highest infection rate. Nineteen fish out of 28 have Trichodina sp., and 14 fish out of 28 have Nematods. Those infection rates were 67.9% and 50.0% respectively. No parasites were collected from the fishes of Gwangryung vally, Dosoon-chun, Gangjeong-chun, and Hyodon-chun.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.174-187
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• 2008

In an effort to identify structure and function of microbial loop in Paldang reservoir, we monitored environmental and biological factors at Kyungan stream (station K), Paldang dam (station P) and the confluence of North and South Han River (station M) from March to December, 2005. DOC concentration was higher in March to May and November than the others. Nutrient concentration in station K detected relatively higher than that of two stations. Both of phosphate and silicate gradually increased at all stations until September, after then decreased. The highest Chl-$\alpha$ concentration was observed at all stations in April, and November. The carbon biomass of bacteria and HNF were relatively higher in March, May and August than the others, whereas that of the ciliate showed no significant difference in monthly fluctuation. Nevertheless, the significant relationships revealed between ciliate (P<0.001) and HNF (P<0.05) and bacterial density. Tintinnopsis cratera, Didinium sp., Vorticella sp., Paramecium sp. and Strombidium sp. were dominant species in ciliate community. The dominant species of phytoplankton were Stephanodiscus hantzschii and Cyclotella meneghiniana at almost stations in Spring, Summer and Autumn. However, Aulacoseira granulata accounted for >95% of phytoplankton biomass at station P and M in Autumn. The carbon biomass of zooplankton was highest at station P and M in June, and relatively higher biomass observed at all stations in August, October and November. Diaphanosoma brachyurum and Bosmina longirostris were dominant in stations P and M of June and in all stations of October and November, respectively. The maximum growth (A. granulata: $0.17\;d^{-1}$, S. hantzschii: $0.14\;d^{-1}$) and grazing rate (A. granulata: 1.93 preys $d^{-1}$, S. hantzschii: 1.63 preys $d^{-1}$) of Bosmina longirostris revealed in algal preys as Aulacoseira granulata and Stephanodiscus hantzschii. In conclusion, these results suggest that bacteria and phytoplankton can play the most crucial source as prey within microbial food chain in Spring and Summer and grazing food chain in Autumn, respectively.