• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.241-247
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• 2004

Isolation and identification of alga-lytic bacteria were carried out. Fifteen isolates of alga-lytic bacteria were screened by the double layer method using A. cylindrica NIES-19 as a sole nutrient and four isolates among them were compared with their alga-lytic activity. The isolate AK-05 exhibiting the highest alga-lytic activity was identified as Acidovorax temperans base on its 16S rDNA sequence. The culture supernatant of the isolate AK-05 was reliable for the alga-lytic. Alga-lytic activity assays of culture supernatant revealed that the major substances for alga-lytic activity were non-proteins and heat stable. The highest alga-Iytic activity was practical under alkaline conditions and at 25${\sim}$$30^{\circ}C$. It is indicating an advantage for the application of water blooms by cyanobacteria in eutrophic lakes where the pH is generally in alkaline region.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.28-35
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• 1998

Microorganisms such as alga are able to uptake toxic and heavy metal ions. After Cd(Ⅱ) was preconcentrated on the carbon paste electrode constructed by incorporating alga (Anabaena), it was determined with differential pulse anodic stripping voltammetry. A well-defined oxidation peak of Cd(Ⅱ) was obtained at - 0.75 V vs. SCE. We investigated the optimum conditions using the peak, which are the effect of the amount of alga, pH, ionic strength, temperature, and preconcentration time on the preconcentration of Cd(Ⅱ) and that of the reduction time and potential on the reduction of Cd(Ⅱ) preconcentrated. Calibration curve for the determination of Cd(Ⅱ) was linear over the range of $1.0{\times}10^6\;M\;to\;8.0{\times}10^6$\;M (R=0.9978) and the detection limit was $5.0{\times}10^{-7}$\;M. The relative standard deviation was 3.1% (n=6) for $7.0{\times}10^{-6}\;M Cd(Ⅱ). In regeneration of the electrode surface with 0.1 M HCl, the response was reproducible continuously by 10 times.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.647-654
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• 2015

A prostrate species of Codium (Bryopsidales, Chlorophyta) was collected from Daejin on the eastern coast of Korea. This alga is morphologically characterized by a prostrate, adherent or pulvinate, dark green thallus that is tightly attached to substratum. The utricles are strongly grouped and cylindrical to slightly clavate. Their apex is rounded to capitated, and it frequently has an alveolate ornament. Hair scars are found in the upper portion of the utricle. The gametangia grow on a short pedicel in the upper part of the utricle. In the phylogenetic tree based on molecular data, this alga is placed in the same clade as C. mozambiquense in UPGMA analysis, and nests in a sister clade of C. lucasii subsp. capense and C. mozambiquense in ML and NJ analyses. However, the genetic distance between the sequences of the Korean alga and the two species is 1.3-1.9%, while that between the Korean alga and C. lucasii from Japan is 1.1% within intraspecific range. The divergence value between the Korean alga and C. lucasii from the type locality (Australia) is 2.7% considered to be interspecific range. As based on this genetic divergence value, the Korean alga together with Japanese C. lucasii can be separated from genuine C. lucasii from the type locality. However, the Korean alga is identified as C. lucasii until those entities are morphologically characterized in species level. This is the first record of C. lucasii in Korea

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.63-68
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• 2010

Ecological characteristics of Undariopsis peterseniana, an endangered brown alga, were investigated from January to December 2007 at Jeju Island, Korea. The U. peterseniana population formed dense patches at depths of 12~17 m depth. Growth in length of the alga reached a maximum of $168{\pm}36cm$ at June. Sorus were observed from May to August, and a maturation peak was detected in June, when bottom seawater temperatures were around $18^{\circ}C$. After zoospore release, the alga bleached and disappeared after August. Developmental initiation of sporophytes occurred at temperature above $15^{\circ}C$, and sorus formation required approximately 236 degree-days. This is the first study to examine a U. peterseniana population throughout the entire year in a natural habitat.

• Fisheries and Aquatic Sciences
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• v.20 no.10
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• pp.25.1-25.5
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• 2017

An economic marine alga, which is considered to be an important source of carrageenan, was collected from Jindo of the southern coast of Korea. This species shares the vegetative and female reproductive features of Ahnfeltiopsis and is characterized mostly by its small size (up to 8 cm), terete to subterete thalli at the lower portion, cartilaginous in texture, dichotomous branches, rarely produced proliferations, and an absence of hypha-like filaments in the medulla. It is distinguished from other Korean species within the genus by the thallus feature. In a phylogenetic tree based on the molecular data, this alga nests in the same clade with A. concinna from Japan but forms a sister clade to A. concinna from Mexico and Hawaii (type locality). However, the genetic distance among those sequences was calculated as 0.1-1.3% for rbcL and 1.1% for COI sequences, considered to be intraspecific variation within the genus. Based on the morphology and molecular analysis, this alga is identified as A. concinna originally described from Hawaii. This is the first record of the species in the Korean marine algal flora.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.1
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• pp.51-60
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• 2022

A green alga specimen was collected from the eastern coast of Korea. This species shared the typical features of genus Ulva and was characterized by irregularly shaped thalli, relatively small and thick thallus, entire undulate margins without serrations, and one or two pyrenoids per cell. In a phylogenetic tree, based on sequences of the nuclear-encoded internal transcribed spacer region, it nests as a sister clade to a few species including Ulva ohnoi, which has a relatively large thallus. This Korean algal specimen differs from the species forming the same subclades, including U. ohnoi, Ulva fasciata, Ulva reticulata, and Ulva gigantean, and has a relatively small (3-8 cm) and thick (60-100 ㎛) thallus. Of these species, U. ohnoi, originally described from Japan, is similar to the Korean alga as it had a thick thallus of 30-90 ㎛, but it has microscopic serrations on the thallus margin, unlike the Korean alga. The genetic distance between the Korean alga species and the aforementioned species was determined to be 1.8%-4.8%, indicating an inter-specific divergence level at the genus Ulva. Herein, Ulva grossa sp. nov. (Ulvales, Chlorophyta) from Korea is described based on the morphological and molecular analyses.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.481-485
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• 2020

A marine red algal species was collected from Honghyeon-ri, Namhae located on the southern coast of Korea during a survey of marine algal flora. This alga shares the generic features of Chondrus, and is characterized by short and thin, canaliculated and crisped fronds as C. retortus. Tetrasporangia are developed from shallow medullary cells on both sides of branches. In a phylogenetic tree based on rbcL sequences, the Korean alga nests in the same clade as C. retortus originally described from Japan. The genetic distance between both sequences within the clade was calculated as 0.0-0.1%. Based on the morphological and molecular data, the alga is identified as Chondrus retortus. This is the first record of C. retortus in Korean marine algal flora.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.611-615
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• 2020

A marine red algal species was collected from Pyengdae-ri, Gujwa in Jeju, Korea during a survey of marine algal flora. This alga shares the generic features of Callophyllis(Gigartinales, Kallymeniaceae), and is characterized by erect and membranous thalli, branches dichotomously or trichotomoulsy divided, margin somewhat undulate or entire and tetrasporangia scattered irregularly in the cortex. In a phylogenetic tree based on rbc L sequences, the Korean alga nests in the same clade as C. mageshimensis originally described from Japan. The genetic distance between both sequences within the clade was 0.0-0.1%. Based on the morphological and molecular data, the alga was identified as Callophyllis mageshimensis. This is the first record of C. mageshimensis in Korean marine algal flora.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.194-202
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• 2003

To isolate alga-lytic bacteria, a number of samples were collected from Lake of Sukchon and Pal'tang reservoir where cyanobacteria blooming occurred. HY0210-AK1, which exhibited high alga-lytic activity, was isolated using Anabaena cylindrica lawn. The morphological and biochemical characteristics of the isolate HY0210-AK1 were very similar to that of the genus Rhizobium. Taxonomic identification including 16S rDNA base sequencing and phylogenetic analysis indicated that the isolate Hy0210-AK1 had a 99.1% homology in its 16S rDNA babe sequence with Sphingobium herbicidovorans. A. cylindrica NIES-19 was susceptible to the alga-lytic bacterial attack. The growth-inhibiting offset of the bacterium was not different on A. cylindrica NIES-19 when Sphingobium herbicidovorans HY0210-AK1 was in the lag, exponential, and stationary growth phase, although the alga-Iytic effect of S. herbici-dovorans HY0210-AK1 that in stationary growth phase was somewhat pronounced at the first time of inoculation. When S. herbicidovorans HY0210-AK1 was inoculated was inoculated with $1\times 10^{8}$ CFU $ml^{-1}$ together with A cylindrica NIES-19, the bacterium proliferated and caused algal lysis. A. cylindrica NIES-19 died when S. herbicidovorans HY0210 AKl was added to the algal culture but not when duly the filtrates from the bacterial culture was added. This suggests that extracellular substances are not responsible for inhibition of A. cylindrica NIES-19 and that algal Iysis largely attributed to direct interaction between S. herbicidovorans HY0210-AK1 and A. cylindrica NIES-19. The alga-lytic bacterium HY0210-AK1 caused cell lysis and death of three strain of Micro-cystis aeruginosa, but revealed no alga-Iytic effects on the Stephanodiscus hantzschii.

• Journal of Plant Biology
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• v.22 no.4
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• pp.135-140
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• 1979

The marine benthic algae of Gojeong-Ri was investigated in a floristic aspect. As a result, 34 species, 7 blue-green, 14 red, 6 brown and 7 green algae were identified as a summer flora from the area. Among them, Sirocoleum kurzii (blue-green alga), Ralfsia clavata (brown alga), Pseudulvella consociata and Cladophora speciosa (green algae) were known as new records to Korea.