• Journal of Plant Biology
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• v.8 no.4
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• pp.7-25
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• 1965

In order to clearify the microflora of the lower course of the Han River and the effect of the marine water on the Han River, the study was carried out at Paldang, Kwangjang, Noryangjin, and Haengju for 4 months (from May till September in 1965). The results obtained are as follows: 1) Water temperature, transparency, light intensity, pH, silicate, and salinity were determined as environmental conditions. 2) Samples collected from 4 stations were identified and classified by Engler's classification system. It resulted in 4 Phyla, 3 Classes, 13 Orders, 25 Families, 61 Genera, 155 Species, and 16 Varieties. The total numbers of phytoplanktons identified are 171. Of the number, 106 species and 12 varieties were recorded in this paper for the first time. 3) A comparative observation on the distribution of marine phytoplanktons and salinity in the Han River showed a fact that the Han River was biologically affected in the middle portion between Noryangjin and Haengju by marine water. Furthermore, the salinity determined at Haengjuduring a day(at high tide, September 26, 1995) supported the above fact. 4) Four species among the identified species are saprobic planktons and it is regarded as the forms derived from Chunggyechon.

• Journal of fish pathology
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• v.25 no.2
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• pp.77-84
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• 2012

Various antibiotics, that could induce the appearance of resistant microorganisms, have been used for treatment or prevention of bacterial diseases in marine and ornamental fish. We determined and characterized the level of antibiotic-resistant bacteria and proportion of multi-drug resistant bacteria in intestinal microflora of both marine fish cultured in Korea and imported ornamental freshwater fish. For this the bacterial species and resistance to antibiotics were investigated in intestine of rock bream Oplegnathus fasciatus cultured in Korea and pearl gourami Trichogaster leeri imported from Singapore to characterise. Although the bacterial species were different, proportions of resistant bacteria to single antibiotics or multi-drug were higher in intestinal microflora of pearl gourami Trichogaster leeri imported from Singapore than in rock bream Oplegnathus fasciatus cultured in Korea. These results indicate that various antibiotics have been being used before trading without measures in the market of asian ornamental fishes, providing high risks for the emergence of multi-drug resistant bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.4
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• pp.328-336
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• 2012

Sik-hae is traditional Korean fermented seafood manufactured by mixing ingredients such as fish, radish, garlic, pepper, etc. To facilitate utilization of the black-edged sculpin Gymnocanthus herzensteini, which is an abundant unusable fish caught in the East Sea, sculpin sik-hae was developed for commercialization as a low-salt fermented food. There was no significant change in the proximate composition of the sculpin sik-hae during storage. The pH of the sculpin sik-hae decreased, whereas the acidity, amino-N, and volatile basic nitrogen contents increased as fermentation progressed. The number of microflora increased gradually up to 14 days of fermentation and then decreased. Based on a sensory evaluation, sculpin sik-hae stored at $-1^{\circ}C$ was superior to that stored at $5^{\circ}C$. Therefore, sculpin sik-hae can be commercialized as a new fermented seafood.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.501-506
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• 2004

Microflora and contamination process of Saengshik products were investigated to ensure microbial safety of Saengshik. Food-borne pathogenic bacteria, such as Staphylococcus aureus, Bacillus cereus, and Clostridium perfringens detected mainly from grains were not removed by washing with tap water and freeze-drying. Contaminations of food-borne pathogenic bacteria occurred through raw material powder processed at other factories and during actual product manufacturing process, because detection rates of final products were higher than those of raw materials. Concentration of food-borne pathogenic bacteria increased with advancing of process after first pulverization. Dusts of powder and powder attached to machine were good media for air-borne microorganisms and caused to increase of food-borne pathogenic bacteria during process. Improvement of manufacturing process and sanitary control of machines arc necessary to ensure microbial safety of Saengshik.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.56-62
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• 1986

Marine fishes, sardine(Sardinops melanosticta), scad kingfish(Caranx equula), horse mackerel(Trachurus japonicus) and file fish(Navodon modestus), were stored for fifty days with partial freezing at$-3.5^{\circ}C$. During the storage, the changes in microflora and volatile nitrogen content was investigated. The fishes exhibited $10^4\;to\;10^6$ of bacterial cells per square centimeter of their skin just before they were submitted to the storage. The bacterial cell number was increased as $10^6\;to\;10^8$ cells as the storage time passed over twenty-two days. Offensive odor which is typical in the spoilage of fishes became strong as increase the bacterial cell numbe. The major isolates among the three hundred strains of bacteria isolated from the fish skins were identified as Pseudomonas I/II, III/IV-H, Vibrio and Moraxella. The same was found in the spoiled fishes, however, Pseudomonas I/II, was predominant on contrast to that of fresh fishes. Pseudomonas III/IV-NH, Flavobacterium, Cytophaga and Micrococcus were also found in early period of storage, but they disappeared as the progress of storage. Nine per cent of isolates were unidentified.

• Journal of Ecology and Environment
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• v.41 no.9
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• pp.235-245
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• 2017

Background: Loading of excess nutrient via bioremediation of polluted sediment to overlying water could trigger anoxia and eutrophication in coastal area. The aim of this research was to understand the changes of overlying water features such as dissolved oxygen (DO); pH; oxidation reduction potential (ORP); $chlorophyll-{\alpha}$ ($Chl-{\alpha}$); and nitrogen nutrients ammonia ($N-NH_4{^+}$), nitrate ($N-NO_3{^-}$), and nitrite ($N-NO_2^-$) when the sediment was not treated (control) and treated by calcium peroxide for 5 weeks. Methods: The water samples were analyzed for measuring physical and chemical properties along with the sediment analyzed by polymerase chain reaction (PCR) including denaturing gradient gel electrophoresis (DGGE) for identifying the phylogenetic affiliation of microbial communities. Results: Results showed that due to the addition of calcium peroxide in sediment, the overlying water exposed the rise of dissolve oxygen, pH, and ORP than control. Among the nitrogen nutrients, ammonia inhibition was higher in calcium peroxide treatment than control but in case of nitrate inhibition, it was reversed than control. $Chlorophyll-{\alpha}$ was declined in treatment column water by 30% where it was 20% in control column water. Actibacter and Salegentibacter group were detectable in the calcium-peroxide-treated sediment; in contrary, no detectable community ware found in control sediment. Both phylogenetic groups are closely related to marine microflora. Conclusions: This study emphasizes the importance of calcium peroxide as an oxygen release material. Interaction with peroxide proved to be enhancing the formation of microbial community that are beneficial for biodegradation and spontaneity of nutrient attenuation into overlying water.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.39-42
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• 2011

This experiment was conducted to evaluate the effect of two different organic acid products as antibiotic replacement in olive flounder paralichthys olivaceus. Fish averaging $3.5{\pm}0.05$ g($mean{\pm}SD$) were fed one of the ten semi-purified diets : Diet 1 ; Control, Diet 2 ; add antibiotics - 50mg OTC/kg body weight/day(OTC), Diet 3 ; Add organic acid bland A(OABA) - 4g/kg diet, Diet 4 ; add organic acid bland B(OABB) - 4g/kg diet for 10 weeks. Total gut microflora counts were significantly higher in the control group compared to the OTC and organic acid groups(P<0.05). Fish fed OABA, OABB and OTC had lower gut Vibrio counts compared to the control, but were not significantly different. Results from the challenge study indicate that mortality in the different treatment groups (50%) was significantly lower than those observed for the control group (100%). There were no differences in mortality between the OTC and organic acid groups. Overall findings from this study indicate that the organic acid blends A and B were as effective as oxytetracycline, an antibiotic, in regulating total gut bacterial numbers, Vibrio counts and providing protection against a pathogen such as Edwardsiella tarda.

• Journal of fish pathology
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• v.11 no.2
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• pp.143-150
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• 1998

Characteristics and distribution of the natural commensal flora in the surrounding environment and tissues of clam in Hadong area were studied under varying conditions of growth media and incubation temperatures. Total numbers of bacteria present in intestinal tract, gill, body fluid and surrounding mud were found to be not influenced by the used BHIA, STA and SNA media. Although the growth rate of bacteria at the condition of $15^{\circ}C$ incubation temperature was slower than that of $25^{\circ}C$ and $35^{\circ}C$, it showed the highest number of total bacteria compared with other two different conditions of incubation temperature. Interestingly, the proportion of bacteria able to form colony on several selective media was higher in replica analysis from nutrient media to selective media than that in direct smearing from samples. The generic diversity of bacteria isolated from the tissues and analyzed by API 20E and API 20NE kit showed similar pattern with each other and distinct from that of environment. The distribution of bacteria in the surrounding mud or mantle fluid of clam indicated a high diversity comparable to that found for the gill or intestinal tract microflora, with Pseudomonas being the prevalent group. It implies that the tissues of clam may probide a selective habitat for a commensal microflora.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.3
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• pp.238-245
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• 2012

In this study, the molecular structures of tet(M) and tet(G) carried by tetracycline (Tc) resistant bacteria in intestinal microflora from the imported ornamental fish were characterized and compared with each other depend on the imported countries. Of the total isolates, approximately 8.9% of the Ent-lac+(lactose fermentative bacteria on coliform media) Tc resistant isolates in fish from three different countries, Singapore, Taiwan and Brazil, were appeared to contain tet(M). Three representative isolates of different countries, Aeromonas spp. JSM-1 (Singapore), JTM-1 (Taiwan) and JBM-1 (Brazil), were isolated and analyzed the molecular structures of tet(M) gene. Interestingly, partial sequence of tet(M) genes (1099 bp) in JBM-1 (Brazil) showed 99.5% homology with the tet(M) found in the Vibrio spp. RV16 isolate, obtained from marine fish in Korea and known to carry Tn1545 parent type of tet(M). In contrast, tet(M) gene in JSM-1 and JTM-1 showed mosaic structure of Tn1545 and Tn916, and 100% homology with each other. It may suggest the presence of various characteristics in terms of tet(M) gene structure. The determined sequence of the tet(G) from Aeromonas spp. JSG-1 and JBG-1 isolated from Singapore and Indonesia ornamental fish respectively showed similar nucleotide sequence homology but revealed a few nucleotide changes in comparison with the sequence of the prototype tet(G) gene (S52437 in GenBank).

• Journal of Environmental Science International
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• v.17 no.7
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• pp.755-765
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• 2008

To investigate correlation between the distribution of marine bacteria and environmental characteristics in the surface sediments of Kamak Bay, chemical oxygen demand(COD), acid volatile sulfide(AVS), ignition loss(IL), total organic carbon(TOC), and total organic nitrogen(TON) were measured and analyzed at 7 stations in winter and summer. In winter, COD and AVS ranged from 13.45 mg/g to 30.06 mg/g(average: 23.58 mg/g) and from 0.03 mg/g to 1.04 mg/g(average: 0.63 mg/g), respectively. IL, TOC, and TON ranged from 8.03% to 11.41%(average: 9.41%), from 1.17% to 2.10%(average: 1.62%), and from 0.09% to 0.18%(average 0.15%), respectively. In summer, COD, AVS, IL, TOC, and TON ranged from 14.06 mg/g to 32.19 mg/g(average: 24.71 mg/g), from 0.03 mg/g to 1.11 mg/g(average: 0.66 mg/g), from 9.00% to 12.15%(average: 10.96%), from 1.27% to 2.12%(average 1.77%), and from 0.12% to 0.19%(average: 0.16%), respectively. These values were relatively higher than those in winter. Kamak Bay had high C/N ratio that might be resulted from the input of terrestrial sewage and industrial wastewater. The number of marine viable bacteria was $8.9{\times}10^4\;cfu/g$ in winter and $9.7{\times}10^5\;cfu/g$ in summer. The most abundant species were Pseudomonas spp., Flavobacterium spp., and Vibrio spp, in the surface sediments of Kamak Bay. It was found that the concentration of organic matters and viable bacterial cells in the inner part were relatively higher than those in the outer of Kamak Bay. The distribution of viable bacterial cells was closely influenced by environmental factors.