• Korean Journal of Microbiology
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• v.26 no.3
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• pp.256-261
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• 1988

Samples from Naktong Estuary had been taken for the characterization of heterotrophic bacterial communities and of the effects of environmental factors on their distribution in estuarine ecosystem. Bacterial communities isolated from seawater region were composed of more euryhalone groups than those from freshwater region, and the bacterial communities of summer were composed of more eurythermal groups than those of winter. Bacterial commnities became more diverse by the input of allochthonous bacteria from terrestrial and freshwater ecosystem, but less diverse by worse environmental conditions such as nutrient load, high salinity, low temperature, and so on.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.68-75
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• 2014

This study investigated the potential use of various organic carbon sources (glucose, glycerol and acetate) and different concentrations of $CO_2$ for culturing marine microalga Dunaliella tertiolecta. Cell growth and lipid production were monitored under heterotrophic, mixotrophic and photoautotrophic modes of cultivation. D. tertiolecta showed the ability to grow under mixotrophic (acetate and glucose), heterotrophic (glucose) and photoautotrophic condition under high $CO_2$ concentration (15%). With all the organic carbon sources (glucose, glycerol and acetate) tested in this study, 1~5% acetate enhanced cell growth rate and lipid content, while higher concentrations of acetate (10% and 15%) were inhibitory and resulted in cell death.

• Journal of Species Research
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• v.11 no.2
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• pp.89-93
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• 2022

Three heterotrophic euglenids from marine water column (Seodo port, Yeosu) and freshwater sediment (Seodong-chun, Incheon), Korea were identified as Entosiphon oblongum Cavalier-Smith and Vickerman, 2016; Euglena longa (Pringsheim, 1936) Marin and Melkonian, 2003; and Keelungia pulex Chan and Moestrup, 2013 based on morphological characters and 18S rDNA sequence analysis. These species are reported taxonomically for the first time from Korea and are described with micrographs. Diagnoses of these species are as follows. Entosiphon oblongum: phagotrophic, gliding, size in vivo, 23.1-29.3 ㎛ (Avg. 26.5 ㎛, n=30) long, ovate with a protrusive feeding siphon (apparatus), several deep grooves and two heterodynamic flagella. Euglena longa: osmotrophic, swimming, size in vivo, 32.3-52.2 ㎛ (Avg. 42.2 ㎛, n=26) long, elongated with many paramylum granules and two flagellar. Keelungia pulex: phagotrophic, gliding, size in vivo, 13.5-19.7 ㎛(Avg. 16.4 ㎛, n=97) long, oblong to ovoid with a hook-shaped ingestion apparatus, several dorsal ridges and two flagella.

• Journal of Species Research
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• v.10 no.4
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• pp.356-363
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• 2021

Heterotrophic nanoflagellates (HNFs, 2-20 ㎛ in size) are substantially capable of controlling bacterial abundance in aquatic environments, and microbial taxonomists have studied ecologically important and abundant HNFs for a long time. However, the classifications of HNFs have rarely been reported in Korea on the basis of morphology and 18S rDNA sequencing. Here, previously reported five HNFs from non-Korean habitats were isolated from Korean coastal seawater or intertidal sediments for the first time. Light microscopic observations and 18S rDNA phylogenetic trees revealed that the five isolated species were Cafeteria burkhardae strain PH003, Cafeteria graefeae strain UL001, Aplanochytrium minuta (formerly Labyrinthuloides minuta) strain PH004, Neobodo curvifilus strain KM017 (formerly Procryptobia sorokini), and Ancyromonas micra (formerly Planomonas micra) strain IG005. Being morphologically and phylogenetically indistinct from its closest species, all isolates from Korea were therefore regarded as identical species detected in other countries. Thus, this result indicates an expansion of known habitats that range from those of the five isolates in natural ecosystems on Earth.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1995-2005
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• 2000

The use of heterotrophic denitrification as an alternative method for supplying alkalinity during sulfur-utilizing autotrophic denitrification was evaluated by examining the effects of external carbon source (both type and concentration) and HRT on denitrification efficiency. Concentrations of $NO_3{^-}-N$ and $COD_{Cr}$ of nitrified landfill leachate used for experiment were 700-900mg/L and 900-2500mg/L. respectively, All experiment was conducted with sulfur packed bed reactors (SPBRs) which were operated at $35^{\circ}C$. The fraction of $NO_3{^-}-N$ removed by heterotrophic denitrification ($HDNR_{fraction}$) to balance the alkalinity consumption by autotrophic denitrification varied with the type of external carbon source. When methanol and sodium acetate was added at theoretical HDNRfraction value. 100% denitrification was achieved without alkalinity addition. However, glucose and molasses require $HDNR_{fraction}$ value greater than theoretical value for complete denitrification. The EBCT and volumetric loading rate at which 100% denitrification efficiency could be achieved were 6.76 h and $2.84kg-NO_3{^-}-N/m^3{\cdot}d$, respectively, based on the fact that 100% denitrification occurred within the bottom 11.5 cm layer of the SPBR. The maximum nitrogen removal rate occurred with 89% removal efficiency at loading rate of $5.05kg-NO_3{^-}-N/m^3{\cdot}d$. However, at short EBCT, clogging of SPBR was observed with excess growth of heterotrophic denitrifiers. This problem may be eliminated by back washing or by separating of heterotrophic denitrification from sulfur-utilizing denitrification.

• ALGAE
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• v.38 no.1
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• pp.57-70
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• 2023

The mortality rate of red-tide dinoflagellates owing to predation is a major parameter that affects their population dynamics. The dinoflagellates Ansanella granifera and Ansanella sp. occasionally cause red tides. To understand the interactions between common heterotrophic protists and A. granifera, we explored the feeding occurrence of nine heterotrophic protists on A. granifera and the growth and ingestion rates of the heterotrophic dinoflagellate Gyrodinium dominans on A. granifera as a function of prey concentration and those of Oxyrrhis marina at a single high prey concentration. The heterotrophic dinoflagellates Aduncodinium glandula, G. dominans, Gyrodinium moestrupii, Luciella masanensis, Oblea rotunda, O. marina, Polykrikos kofoidii, and Pfiesteria piscicida and the naked ciliate Strombidium sp. were able to feed on A. granifera. With increasing mean prey concentrations, the growth and ingestion rates of G. dominans feeding on A. granifera rapidly increased and became saturated or slowly increased. The maximum growth and ingestion rates of G. dominans on A. granifera were 0.305 d^-1 and 0.42 ng C predator^-1 d^-1 (3.8 cells predator^-1 d^-1), respectively. Furthermore, the growth and ingestion rates of O. marina on A. granifera at 1,700 ng C mL^-1 (15,454 cells mL^-1) were 0.037 d^-1 and 0.19 ng C predator^-1 d^-1 (1.7 cells predator^-1 d^-1), respectively. The growth and ingestion rates of G. dominans and O. marina feeding on A. granifera were almost the lowest among those on the dinoflagellate prey species. Therefore, G. dominans and O. marina may prefer A. granifera less than other dinoflagellate prey species. The low mortality rate of A. granifera may positively affect its bloom formation.

• ALGAE
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• v.22 no.1
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• pp.23-29
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• 2007

Free-living heterotrophic stramenopile flagellates, which lack chloroplasts, were encountered in deep-sea sediments of Gippsland Basin (Australia) and classified into 10 species (8 genera, 5 families, 3 orders). Their descriptions were based on living specimens by light microscopy. Those species rarely found in this study were Bicosoeca gracilipes, Caecitellus parvulus, Cafeteria minuta, Cafeteria roenbergensis, Pseudobodo tremulans, Spumella sp., Paraphysomonas sp., Actinomonas mirabilis, Ciliophrys infusionum and Developayella elegans. Their morphological characters and geographic distribution are presented.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.321-327
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• 2013

In the present work, the reactors that harbor bacterial biofilms including ammonia-oxidizing bacteria (AOB) and heterotrophic bacteria were treated with a continuous dose of chlorite ($0.66{\pm}0.01mg/L$) either with or without monochloramine at $1.77{\pm}0.03mg/L$. Both chlorite alone and combined chlorite-monochloramine applications effectively reduced biofilm and bulk AOB levels to near or below the detection limit ($0.6MPN/cm^2$ and 0.2 MPN/ml). The combined chlorite-monochloramine application exhibited greater AOB inactivation than chlorite alone. Unlike AOB, heterotrophic plate count (HPC) was unaffected by chlorite alone. In contrast to chlorite-only application, a combination of chlorite and monochloramine resulted in a significant reduction in HPC levels with log reductions of 3.1 and 3.0 for biofilm and bulk water, respectively. The results demonstrate that the combined chlorite-monochloramine application can provide an effective treatment for the inhibition of AOB and heterotrophic bacteria in a drinking water distribution system.

• Archives of Plastic Surgery
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• v.37 no.3
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• pp.281-284
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• 2010

Purpose: Pseudohypoparathyroidism is a hereditary disorder characterized by symptoms and signs of hypoparathyroidism, typically in association with distinctive skeletal and developmental defects. Hypoparathyroidism is caused by a insufficient end-organ response to PTH (parathyroid hormone). Hypoparathyroidism consists of four types in which the most common form, pseudohypoparathyroidism-Ia, accompany with Albright's hereditary osteodystrophy. We experienced a case of a woman who had been suffering from calcified mass on left foot, diagnosed Albright's hereditary osteodystrophy. Methods: We present a case of a 24-year-old Korean female who visited plastic surgery department with a painful mass on dorsum of the left foot. On the physical exam, bony hard and painful mass, fixed to dermis, was noted. Plain X-ray films demonstrate suspicious calcification on subcutaneous tissue of dorsum of the left foot. The patient was diagnosed pseudohypoparathyroidism 2 years ago at the plastic surgery department. At the visiting time, the laboratory results were within normal range even though the patient actually had a disease. The reason is because the patient has been treated with Vit.D, calcium replacement therapy and thyroid hormone therapy. Moreover, the patient has been treated with anticonvulsant agents due to epilepsy. On the brain computer tomography (CT), calcification was noted on the basal ganglia and dentate nucleus. So we decided the total excision of entire mass from the left foot. Results: We excised main mass with numerous pinhead sized masses which were scattered around the main mass. The $6.0{\times}4.0{\times}0.5\;cm$ sized main mass was bony hard, and its surface was flat and margin was irregular. The permanent biopsy was confirmed that the main mass and all the scattered tiny masses were heterotopic calcification. The patient did not suffer from the pain after the mass excision. The wound has been healed without any problem. Conclusions: Heterotrophic calcification is often accompanied with pseudohypoparathyroidism, but such a huge one is uncommon. We report a case of pseudohypoparathyroidism with heterotrophic calcification developed in dorsum of left foot who was diagnosed by excisional biopsy.

• Journal of Soil and Groundwater Environment
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• v.15 no.4
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• pp.30-38
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• 2010

This study was conducted to determine the potential applicability of slowly released molasses (SRM) to treat nitratecontaminated groundwater. SRM was made by dispersing molasses in hydroxy propyl methyl cellulose-silicamicrocrystalline cellulose matrix. Column test indicated that SRM could continuously release molasses with slowly decreasing release rates of $64.6mg-COD/L{\cdot}h$ up to 65 hrs, $12.1mg-COD/L{\cdot}h$ up to 215 hrs, and $4.4mg-COD/L{\cdot}h$up to 361 hrs. A batch test using an isolated indigenous heterotrophic denitrifier Pseudomonas sp. KY1 having nitrite reductase (nirK) and liquid molasses demonstrated that the bacterium decreased 100 mg-N/L of nitrate to less than 10 mg-N/L at the C/N ratio of 10/1 in 48 hours. In a Pseudomonas sp. KY1-attached Ottawa sand column which continuously received molasses from a SRM-containing reservoir, the bacterium successfully removed nitrate from 20 mg-N/L to 3 mg-N/L during the 361 hours of column operation. The results showed the possibility that SRM can be used as a reliable, longterm extra carbon source for indigenous heterotrophic denitrifiers.