• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.269-276
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• 2010

Total mercury and methylmercury concentrations were determined in 15 commonly consumed aquatic food species using total mercury analyzer and gas chromatography with electron capture detector. The mean total mercury and methylmercury concentrations (mg/kg) were 0.088 and 0.034 in mackerel, 0.061 and 0.016 in hair tail, 0.030 and 0.005 in yellow croaker, 0.032 and 0.008 in Alaska pollock, 0.059 and 0.023 in eastern catfish, 0.110 and 0.045 in snakehead, 0.030 and 0.011 in Japanese common squid, 0.026 and 0.009 in common octopus, 0.035 and 0.008 in swimming crab, 0.009 and not detected (ND) in oyster, 0.011 and ND in shortneck clam, 0.008 and ND in mussel, 0.018 and ND in sea mustard, 0.007 and ND in nori, and 0.019 and ND in sea tangle, respectively. The total weekly dietary intakes of total mercury and methylmercury were estimated, respectively, using food consumption data from diet surveys and the concentrations of total mercury and methylmercury from this study. They were $0.178\;{\mu}g/kg$ body weight (b.w.)/week (3.57% of provisional tolerable weekly intake (PTWI)) and $0.052\;{\mu}g/kg$ b.w./week (3.34% of PTWI) respectively, and all were within their respective PTWI set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Therefore, considering that the main contributor to mercury intake in the diet is aquatic foods and that the 15 aquatic food species examined in this study are highly consumed, it is concluded that the mercury levels in the foods measured in this study do not present a concern for consumer health.

• Journal of Life Science
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• v.26 no.11
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• pp.1259-1268
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• 2016

In this study, we investigated antimicrobial peptide from the acidified muscle extract of Mytilus coruscus, which mostly inhabits China, Japan, and Korea, to develop a natural product-derived antibiotics substitution in terms of its abuse and restriction. Antimicrobial peptide was purified by $C_{18}$ reversed-phase high-performance liquid chromatography and was detected as having a molecular mass of 6,701 Da by MALDI-TOF/MS. The N-terminal amino acid sequence of the purified peak was obtained from edman degradation, and 20 identified residues shown 100% identity with the N-terminus region of sperm-specific protein and protamine-like PL-II/PL-IV precursor of Mytilus californianus. We also identified 60 open-reading frame (ORF) encoding amino acids with 183 bp of purified peptide based on the obtained amino acid residues. The amino acid sequence of ORF showed 100% and the nucleotide sequence revealed 97.2% identity with the protamine-like PL-II/PL-IV precursor of Mytilus californianus. Synthesized antimicrobial peptide showed antimicrobial activity against gram-positive bacteria, including Bacillus cereus (minimal effective concentration [MEC], $20.8{\mu}g/ml$), Bacillus subtilis (MEC, $0.2{\mu}g/ml$), Streptococcus mutans (MEC, $0.2{\mu}g/ml$), gram-negative bacteria including Pseudomonas aeruginosa (MEC, $5.7{\mu}g/ml$), Escherichia coli (MEC, $2.6{\mu}g/ml$) and fungi, Candida albicans (MEC, $56.3{\mu}g/ml$). In addition, synthesized peptide showed stable activities under heat and salt conditions against gram-positive and gram-negative bacteria, but was inhibited by salt against only C. albicans. With these results, isolated peptide from M. coruscus could be an alternative agent to antibiotics for defending against pathogenic microorganisms, and helpful information to understand the innate immune system of marine invertebrates.

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.179-187
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• 2010

The Theory of Island Biogeography describes that the number of species on an island affected by island area and distance from the mainland. This study was performed to compare and analyze the community structure of the macro-invertebrates in three isolated islands, around Korean waters in terms of the Theory of Island Biogeography. Macrobenthic animals were collected using a modified underwater quadrat in August 2009. A total of 104 macrobenthic species were sampled with a mean density of 399 individuals $m^{-2}$ and biomass of 1,506.70 g $m^{-2}$. Based on the abundance and biomass data, there were 10 dominant species accounting for approximately 67.17% of total individuals. The highest densities were found in the amphipoda Amphipoda spp., the bivalvia Modiolus agripetus and Mytilus coruscus, the Sipunculida Phascolosoma scolops and the polychaeta Syllidae unid.. On the contrary, the top ten species made up 95.66% of the total biomass while the three most abundant, the bivalves M. coruscus, Streostria circumpicta and M. agripetus. The conventional multi-variate statistics (cluster analysis and non-metric multi-dimensional scaling) applied to assess spatial variation in macrobenthic assemblages. Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity identified 2 station groups. The group 1 was consisted with Gageodo (except for lower station at Transect 2) and Dokdo station and was numerically dominated by the polychaetes Eunice antennata and Syllidae unid., the cirripedia Megabalanus rosa and the bivalvia M. coruscus. However, group 2 was associated with Sohwado station and was characterized by high abundance of the anomura Petrolisthes japonicus, the gastropoda Lirularia pygmaea and the brachiopoda Coptothyris grayi. In conclusion, these results suggested that the species diversity and community structure of macrobenthos in three isolated island seemed slightly related to island area and distance from the mainland.

• Analytical Science and Technology
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• v.29 no.4
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• pp.170-178
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• 2016

Accuracy and precision of ID methods for different spike isotopes of ⁷⁶Se, ⁷⁷Se, and ⁷⁸Se were compared for the analysis of Selenium using quadrupole ICP/MS equipped with Octopole reaction cell. From the analysis of Se inorganic standard solution, all of three spikes showed less than 1 % error and 1 % RSD for both short-term (a day) and long-term (several months) periods. They showed similar results with each other and ⁷⁸Se showed was a bit better than ⁷⁶Se and ⁷⁷Se. However, different spikes showed different results when NIST SRM 1568a and SRM 2967 were analyzed because of the several interferences on the m/z measured and calculated. Interferences due to the generation of SeH from ORC was considered as well as As and Br in matrix. The results showed similar accuracy and precisions against SRM 1568a, which has a simple background matrix, for all three spikes and the recovery rate was about 80% with steadiness. The %RSD was a bit higher than inorganic standard (1.8 %, 8.6 %, and 6.3 % for ⁷⁸Se, ⁷⁶Se and ⁷⁷Se, respectively) but low enough to conclude that this experiment is reliable. However, mussel tissue has a complex matrix showed inaccurate results in case of ⁷⁸Se isotope spike (over 100 % RSD). ⁷⁶Se and ⁷⁷Se showd relatively good results of around 98.6 % and 104.2 % recovery rate. The errors were less than 5 % but the precision was a bit higher value of 15 % RSD. This clearly shows that Br interferences are so large that a simple mathematical calibration is not enough for a complex-matrixed sample. In conclusion, all three spikes show similar results when matrix is simple. However, ⁷⁸Se should be avoided when large amount of Br exists in matrix. Either ⁷⁶Se or ⁷⁷Se would provide accurate results.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.123-130
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• 2023

Salmonella spp. are prevalent foodborne pathogens that are infective at relatively low concentrations, thus posing a serious health threat, especially to young children and the elderly. In several countries, the management and regulation of Salmonella spp. in food, including seafood, adhere to a negative detection standard. The risk of infection is particularly high when seafood is consumed raw, which underscores the importance of timely detection of pathogenic microorganisms, such as Salmonella. Accordingly, this study aimed to develop a combined pre-treatment and detection method that includes pre-culture and DNA extraction in order to detect five species of Salmonella at concentrations below 10 CFU/mL in seafood. The effectiveness of the proposed method was assessed in terms of the composition of the enrichment (pre-culture) medium, minimum incubation time, and minimum cell concentration for pathogen detection. Furthermore, a practical DNA extraction method capable of effectively handling high salt conditions was tested and found to be successful. Through polymerase chain reaction, Salmonella spp. Were detected and positively identified in shellfish samples at cell concentrations below 10 CFU/g. Thus, the proposed method, combining sample pre-treatment and cell culture with DNA extraction, was shown to be an effective strategy for detecting low cellular concentrations of harmful bacteria. The proposed methodology is suitable as an economical and practical in situ pre-treatment for effective detection of Salmonella spp. in seafood.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.163-171
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• 1988

The paralytic shellfish poisoning was occurred among 25 laborers who worked at breaking-up of ships in Pusan for 5 days from March 29 to April 2 of 1956. For the purpose of accurately defining the paralytic shellfish poison(PSP) , the authors carried out mouse bioassay and chemical analysis. The results were summarized as follows: 1. The mean amount of Paralytic shellfish toxin was $1,207.8{\mu}g$ Per 100gm meat, and the mean death time of mouse was 5 minutes 16 second. 2. The properties of the PSP were mainly gonyautoxin group by chemical analysis(TLC, IR, $^{1}H-NMR$).

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.351-361
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• 2019

To investigate the temporal distribution of planktonic larvae of Tegillarca granosa and Anadara kagoshimensis in the Boseong coastal waters of South Korea, samples of planktonic bivalve larvae were taken from the coastal waters from June to September 2018 (this consisted of monthly sampling in June, July, and September with three- or four-day interval sampling in August). The samples were analyzed using metagenomic next-generation sequencing methods (target gene: mitochondria cytochrome c oxidase 1 region). In this study, a total of 21 bivalve operational taxonomic units (OTUs) were detected with the most abundant bivalve OTUs (relative mean abundance >1%) belonging to Magallana sikamea, Xenostrobus atratus, Musculista senhousia, Magallana gigas, Sinonovacula constricta, Anadara kagoshimensis, Kurtiella aff. bidentata, and Tegillarca granosa. In particular, Tegillarca granosa and Anadara kagoshimensis (the main fishery resources on the Boseong coast) accounted for 0.51-12.50% (average 4.00%) and 0.01-12.50% (1.92%), respectively. The planktonic bivalve larvae were most abundant from July to August. Anadara kagoshimensis was most abundant in early August but rare in the other investigated periods, whereas Tegillarca granosa was more abundant in late August. Bivalve larvae monitoring is important to predict the production of bivalve fisheries. Therefore, intensive monitoring is needed to understand the changes in planktonic bivalve larvae because potentially rapid turnover can respond to the ecological interaction of spawning bivalves.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.19-26
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• 1979

To evaluate the sanitary conditions of four species of commercial shellfish (Crassostrea gigas, Tapes japonica, Mytilus coruscus and Anadara granosa), the psychrotrophic coliforms and the bacterial flora were monthly examined from January to December, 1978. Viable cell counts of the samples submitted were $1.3\times10^3\~2.5\times10^6/g$ and the numbers of coliform and E. coli were above $0\~5.5\times10^2/g\;and\;2\~9.2\times10^2/100g$ respectively. Among the 373 coliform bacteria isolated from the samples submitted, 298 strains were identified as coliform by IMViC test, $44^{\circ}C$ culture and gelatin liquefaction test. E. coli type I and K. aerogenes type I were the most predominant ones among the identified coliform as 138 strains and 71 strains respectively. The psychrotrophic coliform growing at $5^{\circ}C$ were 186 $strains(50\%)$ among 373 strains of isolated coliform. Vibrio and Pseudomonas were the most predominant groups. Among 453 strains of isolated bacteria, Vibrio was 240 $strains(53\%)$ and Pseudomonas was 91 $strains(20\%)$. Moraxella, Acinetobacter, Enterobacteriaceae and Flavobacterium-Cytophage were scantly detected. In seasonal variation of general bacterial flora, a lot of Vibrio appeared from May to October, did Moraxella during the winter season and the other genuses showed no seasonal change.

• 한국해양학회지
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• v.4 no.1
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• pp.36-48
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• 1969

The larvae of Mytilus coruscus were grown at the room temperature of approximately 15.1C under several different sulture conditions, i.e., salinity, population of the larvae, density and kind of food organisms, etc. (1) The egg of Mytilus coruscus obtained in the laboratory measured about 73.0${\mu}$ in diameter. The embryos gradually developed into larvae up to 179.0${\mu}$ shell length with the shell height of 135.9${\mu}$ even in the absence of the algal food. Beyond this size, however, the growth of larvae was considerably retarded, indicating that the better growth could be expected if the food began to be fed four days after spawning. (2) The larvae began settling upon reaching 281.4${\mu}$ to 310.9${\mu}$ in shell length or 264.3${\mu}$ to 301.9${\mu}$ in shell height. When the shell length reaches 322.6${\mu}$ to 337.1${\mu}$, the shell height also reaches about the same, i.e., 321.5${\mu}$ to 346.2${\mu}$. (3) Daily rate of food consumption was determined by the size of the larvae and the species of the algal food. Regardless of the species of food given, the rage of food consumption remained almost the same until the larva reached the straight-hinge stage, and marked variations were found as the larvae grew larger. Daily rate of food consumption was shown as follow; Chaetoceros calcitrans : Y=2.99167e$\^$0.000018243x$\^$2// Cyclotella nana : Y=3.00324e$\^$0.000015481x$\^$2// Monochrysis lutheri : Y=3.000056e$\^$0.000014485$\^$2// (4) Suitable amount of the food to be given was about five times of the consumed food by Mytilus coruscus. (5) When the numbers of the larvae was higher than ten per milliliter, the growth was significantly retarded. (6) Monochrysis lutheri and Cyclotella nana were much better than Chaetoceros calcitrans as the food of Mytilus coruscus, and even the same food organism showed some difference with the age of the organism. (7) Sea water of higher salinity showed the better result in the growth of the larvae and the water with the specific gravity of 1.020 or below was dangerous for the larvae. (8) The mean growth of the larvae of Mytilus coruscus under lavorable condition was shown as follows: shell length 121.8${\mu}$ to 179.0${\mu}$ : Y=119.18+7.42X 196.7${\mu}$ to 322.6${\mu}$ : Y=203.144+7.687X 322.6${\mu}$ to 985.1${\mu}$ : Y=302.5978+11.8356X shell height 86.3${\mu}$ to 135.9${\mu}$ : Y=86.22+6.40X 158.1${\mu}$ to 321.5${\mu}$ : Y=162.998+10.027X 321.5${\mu}$ to 1,215.4${\mu}$ : Y=309.3701+16.258X Relationships between the shell length and shell height were shown as follows: shell length 121.8${\mu}$ to 179.0 : Y=0.83726X-15.79165 196.7${\mu}$ to 322.6 : Y=1.29909X-100.58610 322.6${\mu}$ to 985.1${\mu}$ : Y=1.3536X-101.6806

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.238-249
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• 2005

The present study was carried out to apprehend that the pollutants originating from Jinhae Industrial Complex affect benthic polychaetous community in the northern Jinhae bay. An investigation on the macrobenthic community in Jinhae bay was conducted in September, December of 2002 and March of 2003. The benthic fauna showed mean density of 2,151 ind. $m^{-2}$ in September of 2002, 2,427 ind. $m^{-2}$ in December of 2002 and 2,394 ind. $m^{-2}$ in March of 2003. Major faunal groups are polychaetes, crustaceans and mollusks, corresponding to $73.7\%,\;12.0\%\;and\;11.7\%,$ in total mean density during all of the sampling season, respectively. The most abundant species was Lumbrineris longifolia $(24.85\%),$ followed by Tharyx sp. $(21.70\%),$ Mesochaetopterus sp. $(6.20\%),$ Heteromastus filiformis $(5.39\%),$ Prionospio sp. $(5.18\%),$ Clycinde sp. $(4.29\%),$ etc. Tharyx sp. was the highest abundant species in September of 2002, and Lumbrineris longifolia was the dominant species in another sampling seasons. The density and the species number of polychaetes were high around Chori Is. and poor near Jinhae Industrial Complex area. Cluster analysis based on the species composition showed that Jinhae bay could be divided into three regions except in March of 2003. In December of 2002, there are very distinct regions by the cluster analysis. The density of benthic polychaetes in Jinhae bay was higher than that in the other coastal area of Korea, due to the predominance by some of opportunistic species, such as Lumbrineris longifolia, Tharyx sp. and Heteromastus filiformis, etc. It means that the study area were in the process of organic enrichment.