• 한국해양환경ㆍ에너지학회지
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• 제16권1호
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• pp.25-35
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• 2013

실내실험과 현장관측을 통해서 용존태무기질소(dissolved inorganic nitrogen; DIN) 제한 하에서 유독와편모조류 Alexandrium tamarense와 A. catenella의 생존과 우점화 전략을 살펴보았다. 현장관측결과 마산만에서 Alexandrium 속이 출현하는 기간동안 DIN이 식물플랑크톤의 성장 제한영양염으로 나타났다. 성장동력학 실험으로부터 도출된 질산염의 Ks값은 현장에서 우점하는 규조류보다 A. tamarense와 A. catenella가 높아, 영양염 경쟁에 있어 불리한 위치에 있는 것으로 나타났다. 하지만 A. tamarense와 A. catenella는 DIN 제한하에서 요소나 아미노산과 같은 용존유기질소 (dissolved organic nitrogen; DON) 화합물을 성장에 이용하였다. 따라서 마산만과 같이 Alexandrium 속이 출현하는 봄~여름까지 DIN이 제한영양염으로 작용하는 환경에서 DON의 흡수능력은 이들 종이 성장을 유지하는데 큰 역할을 할 뿐만 아니라 종의 우점과정 및 종간 경쟁에서도 중요한 영향을 줄 것으로 보인다.

• 생명과학회지
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• 제14권2호
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• pp.301-308
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• 2004

진해만에서 분리한 무독성 Alexandrium tamarense와 이미 보고된 독성을 가진 A. tamarense종 간의 접속공, 제1상판, 후속공의 형태를 상호 비교하였다. 형태적으로 독성종과 거의 일치되지만, HPLC나 생체실험에서 진해만에서 새롭게 분리한 종은 독성이 전혀 나타나지 않았다. lectin반응결과 무독종 A. tamarense은 PNA와 강한 반응을 보여, 세포표면에 lactose나 galactose와 같은 물질이 많이 분포하고 있음을 보였다. 또한, 단백질 전기영동시 무독종은 유독종과 달리 21 kDa 정도 부위에서 종 특이적 밴드를 보였다. 따라서 PNA lectin이나 면역학적 방법을 이용하면 무독종 A. famarense을 신속하게 동정하는데 이용될 수 있다.

• 한국환경과학회지
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• 제22권12호
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• pp.1571-1577
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• 2013

The effects of irradiance on the growth of toxic dinoflagellates Alexandrium tamarense (Masan Bay strain) and Alexandrium catenella (Jinhae Bay strain) were investigated in the laboratory. At $15^{\circ}C$ and 30 psu for A. tamarense and $25^{\circ}C$ and 30 psu for A. catenella, the irradiance-growth curve showed the maximum growth rate (${\mu}_{max}$) of 0.31 $day^{-1}$ with half-saturation photon flux density (PFD) ($K_I$) of 44.53 ${\mu}molm^{-2}s^{-1}$, and a compensation PFD ($I_c$) was 20.67 ${\mu}molm^{-2}s^{-1}$ for A. tamarense, and ${\mu}_{max}$ of 0.38 $day^{-1}$ with $K_I$ of 59.53 ${\mu}molm^{-2}s^{-1}$, and $I_c$ was 40.80 ${\mu}molm^{-2}s^{-1}$ for A. catenella. The $I_c$ equated to a depth of 8~9 m from March to June for A. tamarense and 6~7 m from March to June for A. catenella. These responses suggested that irradiance at the depth near the middle layer in Masan Bay would provide favorable conditions for two species.

• 생명과학회지
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• 제12권3호
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• pp.250-255
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• 2002

독성이 있는 특이한 편모충인 Alexandrium tamarense의 구별하기 위한 종특이적인 형광 DNA탐침 AT1이 서로 다른 3가지의 고정액에서, 그리고 배양기간의 차이와 whole cell hybridization을 사용하는 광학 현미경 또는 형광 현미경에 의한 세포밀도 측정에 있어서 hiding activity를 비교하는 방법으로 여러 다른 종의 실험에 사용되어졌고, 그의 결과를 보고하는 바이다. 형광 DNA탐침 AT1은 특이적으로, A. tamarense에 결합했지만, 형태학적으로 유사한 다른 편모충에는 결합하지 않았다. 특히 형태적으로 A. tamarense에 유사한 A. catenella는 형광 DNN탐침 AT1에 결합하지 않았다. A. tamarense은 다른 세가지 고정액을 처리하였을 때, 고정액과 상관없이 강한 형광신호를 발산하였다. 추가해서 말하면, 배양기간에 관계없이 형광 DNA탐침 AT1의 biding activity는 강했다. 광학 현미경에 의해서 측정 되어지기 보다는 형광현미경에 의해서 세포밀도가 측정되었다. 형광 DNA탐침 AT1을 이용한 A. tamarense의 동정과 계산은 이 분야에서 새로운 생물독성 감시와 예측 시스템에 기여 할 것이다.

• Journal of the korean society of oceanography
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• 제39권3호
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• pp.163-171
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• 2004

Sequences of the large subunit ribosomal (LSD) rDNA D1-D2 region of Alexandrium catenella(=A. sp. cf. catenella) and A. tamarense isolates, which were collected along the Korea coasts, were analyzed to understand their phylogenetic relationships and geographical distributions. All A. catenella and A. tamarense isolates belonged to the A. tamarense/catenella/fundyense complex and were grouped with the North American and temperate Asian ribotypes, respectively, regardless of the presence or absence of a ventral pore in the first apical plate. A consistent and peculiar characteristic that differentiated the Alexandrium isolates was amplification of a second PCR product with a lower molecular weight in addition to the predicted one; ten A. catenella isolates belonging to the temperate Asian ribotype yielded this additional PCR product. Sequence alignment revealed that the shorter PCR product resulted from an unusual large deletion of 87 bp in the LSD rDNA D1 domain. The North American and temperate Asian ribotypes were prevalent along the Korean coasts without geographical separation. Given the high genetic homogeneity among widely distributed Alexandrium populations, each ribotype appeared to be pandemic rather than to constitute a distinct regional population.

• Ocean Science Journal
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• 제40권3호
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• pp.155-166
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• 2005

New PCR primers (N=18) were designed for the isolation of complete SSU to LSU rDNA sequences from the dinoflagellate Alexandrium tamarense. Standard PCR, employing each primer set selected for amplifications of less than 1.5 kb, successfully amplified the expected rDNA regions of A. tamarense (Korean isolate, HY970328M). Complete SSU, LSU rDNAs and ITS sequences, including 5.8S rDNA, were recorded at 1,800 bp, 520 bp and 3,393 bp, respectively. The LSU rDNA sequence was the first report in Alexandrium genus. No intron was found in the LSU rRNA coding region. Twelve D-domains within the LSU rDNA were put together into 1,879 bp (44.4% G+C), and cores into 1514 bp (42.8% G+C). The core sequence was significantly different (0.0867 of genetic distance, 91% sequence similarity) in comparison with Prorocentrum micans (GenBank access. no. X16108). The D2 region was the longest in length (300 bp) and highly variable among the 12 D-domains. In a phylogenetic analysis using complete LSU rDNA sequences of a variety of phytoplankton, A. tamarense was clearly separated with high resolution against other species. The result suggests that the sequence may resolve the taxonomic ambiguities of Alexandrium genus, particularly of the tamarensis complex.

• 환경생물
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• 제22권1호
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• pp.200-205
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• 2004

유독성 와편모조류 Alexandrium tamarense 휴면시스트의 발아율을 여러 환경조건하에서 측정하여 각각의 환경요인과 휴면시스트의 발아율과의 관계를 밝히고자 하였다. 마산만에서 채집한 해저니로부터 휴면시스트를 분리하여 실험실 배양을 통해 온도, 광조건의 유무, 염분 그리고 저니층의 깊이에 따른 발아율을 각각 조사하였다. 온도별 발아율은 $15^{\circ}C$에서 가장 높았으며 $10^{\circ}C$에서도 높은 발아율이 기록된 반면, $20^{\circ}C$와 $25^{\circ}C$에서는 거의 발아되지 않았다. 광조건의 유무에 따른 발아율은 명조건과 암조건에서 두드러진 차이를 나타내지 않았다. 염분에 따른 발아율도 큰 차이를 보이지 않았다. 저니층별 발아율은 3월에 분리된 휴면시스트의 경우는 표층이 저층보다 낮은 발아율을 보였지만, 11월에는 표층이 저층보다 높은 발아율을 보여 시기별로 대조적인 결과를 얻었다. 따라서, 마산만에서 분리된 A. tamarense 휴면시스트의 발아는 수온의 변화에 가장 큰 영향을 받는다고 판단된다.

• Ocean and Polar Research
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• 제25권4호
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• pp.625-631
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• 2003

While phytoplankton diversity and productivity in the Southern Ocean has been widely studied in recent years, most attention has been given to elucidating environmental factors that affect the dynamics of micro-plankton (mainly diatoms) and nano-plankton (mainly Phaeocystis antarctica). Only limited effects have been given to studying the occurrence and the potential risks associated with the blooming of dinoflagellates in the relevant waters. This study focused on the appearance and toxicological characteristics of a toxic dinoflagellate, Alexandrium tamarense, identified and isolated from the Drake Passage in a research cruise from November to December 2001 The appearance of A. tamarense in the Southern Ocean indicates the risk of a paralytic shellfish poisoning (PSP) outbreak there and is therefore of scientific concern. Results showed that while the overall quantity of A. tamarense in water samples from 30meters below the sea surface often comprised less than 0.1% of the total population of phytoplankton, the highest concentration of A. tamarense (20 cells $L^{-1}$) was recorded in the portion of the Southern Ocean between the southern end of South America and the Falkland Islands. Waters near the Polar Front contained the second highest concentrations of 10-15 cells $L^{-1}$. A. tamarense was however rarely found in waters near the southern side of the Polar Front, indicating that cold sea temperatures near the Antarctic ice does not favor the growth of this dinoflagellate. One strain of A. tamarense from this cruise was isolated and cultured for further study in the laboratory. Experiments showed that this strain of A. tamarense has a high tolerance to temperature variations and could survive at temperatures ranging from $5-26^{\circ}C$. This shows the cosmopolitan nature off. tamarense. With regard to the algal toxins produced, this strain of A. tamarense produced mainly C-2 toxins but very little saxitoxin and gonyailtoxin. The toxicological property of this A. tamarense strain coincided with a massive death of penguins in the Falkland Islands in December 2002 to January 2003.

• 환경생물
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• 제24권3호
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• pp.275-281
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• 2006

We examined effects of water temperature, salinity, irradiance, and different media on the growth of the toxic dinoflagellate Alexandrium tamarense (HYM9704), which was isolated from Jinhae Bay, Korea. The ranges of temperature and salinity in which the strain was able to grow were $10{\sim}20^{\circ}C$ and $20{\sim}34$ psu, respectively. These values were in accordance with those observed in situ. The maximum growth rates of axenic A. tamarense (HYM9704) was $0.25d^{-1}$ at $15^{\circ}C$, 30 psu, and $100{\mu}Em^{-2}s^{-1}$. The temperature affected the growth rates of axenic A. tamarense more significantly than the salinity. The type of culture media did not affect the growth rates of axenic A. tamarense. The strain in N-limited and P-limited media went into the stationary phase faster than that in T1 and T1/2 medium.

• ALGAE
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• 제23권4호
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• pp.251-255
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• 2008

In Gamak Bay, Paralytic Shellfish Poisoning (PSP) was first detected from seafoods in 2003, however the toxin source is unknown yet. In this study, we report potential PSP producers of toxic dinoflagellates, describing morphology and abundance of cysts isolated from surface sediment of Gamak Bay. The most abundant type in these cysts was characterized with ellipsoidal and transparent wall identical to Alexandrium catenella and/or A. tamarense. Germination experiment of the cysts revealed that all motile cells germinated were morphologically identified as A. tamarense. This result suggests that A. tamarense may relate to PSP contaminations in Gamak Bay. Moreover, bottom water temperature in Gamak Bay is favorable for germination of A. tamarense cysts. Further studies are required to carry out the PSP monitoring for preventing the risk of PSP events that may outbreak in future at Gamak Bay.