• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.527-534
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• 2015

The twenty six specimens of leptocephali (15.8-32.6 mm TL) of the family Congridae, collected from southeastern waters offshore of Jeju Island during August 2014, and were identified by means of morphology and genetics. Those specimens were identified as belonging to the family Congridae based on various combinations of morphological characters. An analysis of the partial 12S rRNA sequences (886 base pairs) of mitochondrial DNA showed that our specimens must be Gnathophis nystromi, because their sequences were concordant with those of G. nystromi adult (genetic distance= 0.001), furthermore their total myomeres being consistent with those of G. nystromi adult. Catch rates of G. nystromi leptocephali were higher in the offshore regions than coastal regions of Jeju Island. The smallest leptocephali (< 20 mm TL) were collected offshore from Jeju Island. We hypothesize that one of the spawning grounds of G. nystromi is located offshore in the Jeju Island. In conclusion, the hatched preleptocephali of G. nystromi might have been transported from offshore near Jeju Island to the Korea Strait by the Kuroshio Current and Tsushima Warm Current.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1698-1707
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• 2013

Optimization of the dietary formulation is the most effective way to reduce methane. Nineteen feed ingredients (brans, vegetable proteins, and grains) were evaluated for their potential to generate methane and change methanogen diversity using an in vitro ruminal fermentation technique. Feed formulations categorized into high, medium and low production based on methane production of each ingredient were then subjected to in vitro fermentation to determine the real methane production and their effects on digestibility. Methanogen diversity among low, medium and high-methane producing groups was analyzed by PCR-DGGE. The highest methane production was observed in Korean wheat bran, soybean and perilla meals, and wheat and maize of brans, vegetable protein and cereal groups, respectively. On the other hand, corn bran, cotton seed meal and barley led to the lowest production in the same groups. Nine bacteria and 18 methanogen 16s rDNA PCR-DGGE dominant bands were identified with 83% to 99% and 92% to 100% similarity, respectively. Overall, the results of this study showed that methane emissions from ruminants can be mitigated through proper selection of feed ingredients to be used in the formulation of diets.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1915-1918
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• 2008

An entomopathogenic fungus was isolated from an infected aphid. The isolate conformed most closely to Lecanicillium attenuatum CBS 402.78 (AJ292434) based on the internal transcribed spacer (ITS) region of its 18S rDNA, and thus was designated L. attenuatum CNU-23. Laboratory and field evaluations of CNU-23 blastospores were carried out for the control of green peach aphids. The laboratory evaluations of CNU-23 revealed an aphid mortality of about 80% with an estimated $LT_{50}$ of 3.72 days after the application of CNU-23 at $1{\times}10^6$ blastospores/ml. Meanwhile, the field evaluations of CNU-23 performed on greenhouse pepper plants during the rainy season showed an aphid mortality ranging from 72% to 97%. Significant sporulation was observed in the aphids treated with CNU-23. Therefore, the results suggest that L. attenuatum CNU-23 can be used as a biocontrol agent for green peach aphids on greenhouse pepper plants.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.131-136
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• 2016

Clostridium novyi (C. novyi) is a gram positive, non-capsulated, motile, obligatory anaerobe that produces endospores. Both C. novyi type A and B produce a bacteriophage encoded lethal alpha toxin which belongs to a family of large clostridial cytotoxins. These large clostridial cytotoxins of C. novyi bind to the uncharacterized receptors on host vascular endothelial cells, which leads to the loss of integrity of the vascular endothelium with subsequent edema, refractory hypotension, organ failure, and sudden death. A total of 13 sudden death cases were submitted to Chonbuk National University-Veterinary Diagnostic Center between June and October, 2015. The samples, mainly liver, were collected in sterile vials after necropsy and processed within 12~24 hours for diagnosis, isolation and identification of C. novyi. All of the 4 gram positive samples showed amplification by PCR. Out of 4 positive samples, 3 were detected to be C. novyi type B and 1 was detected as C. novyi type A. Based on the 16S rDNA sequence analysis, 1 case (150564) showed 99% similarity with C. novyi type A while other 3 cases (150388, 150557 and 150775) presented 99% similarity with C. novyi type B. Based on the results, C. novyi was found to be prevalent in Korean pig farms and causes sudden death to finishing pigs or sows during summer season. Thus, C. novyi should be considered for differential diagnosis on sudden death cases during the summer season.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.888-894
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• 2014

Seventeen specimens of leptocephali [9.8-44.5 mm total length (TL)], of the family Ophichthidae, were collected from southeastern waters off Jeju Island and the Korea-Japan intermediate zone, and identified by means of morphology and genetics. These specimens were identified as belonging to the subfamily Ophichthinae based on various combinations of morphological characters: 211-215 total myomeres; 7 gut swellings; 2 liver lobes connected with the gall bladder on the second lobe; 6-7 postanal pigments present from anus to caudal margin. An analysis of the partial 12S rRNA sequences (849 base pairs) of mitochondrial DNA showed that our specimens must be Ophisurus macrorhynchos because their sequences were concordant with those of the adult O. macrorhynchos (genetic distance = 0.000). Furthermore, their total myomeres were consistent with those of the O. macrorhynchos adult. This is the first time that the morphological characteristics of O. macrorhynchos leptocephali have been described for Korean waters, and we suggest diagnostic characteristics for the genus Ophisurus leptocephali. We hypothesize that one of the spawning grounds of O. macrorhynchos is located in the southeastern part of Jeju Island.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.952-957
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• 2008

A Gram-negative bacterium, named LY402, was isolated from contaminated soil. 16S rDNA sequencing and measurement of the physiological and biochemical characteristics identified it as belonging to the genus Enterohacter. Degradation experiments showed that LY402 had the ability to aerobically transform 79 of the 91 major congeners of Aroclor 1242, 1254, and 1260. However, more interestingly, the strain readily degraded certain highly chlorinated and recalcitrant polychlorinated biphenyls (PCBs). Almost all the tri- and tetra-chlorobiphenyls (CBs), except for 3,4,3',4'-CB, were degraded in 3 days, whereas 73% of 3,4,3',4'-, 92% of the penta-, 76% of the hexa-, and 37% of the hepta-CBs were transformed after 6 days. In addition, among 12 octa-CBs, 2,2',3,3',5,5',6,6-CB was obviously degraded, and 2,2',3,3',4,5,6,6'- and 2,2',3,3',4,5,5',6'-CB were slightly transformed. In a metabolite analysis, mono- and dichlorobenzoic acids (CBAs) were identified, and parts of them were also transformed by strain LY402. Analysis of PCB degradation indicated that strain LY402 could effectively degrade PCB congeners with chlorine substitutions in both ortho- and para-positions. Consequently, this is the first report of an Enterobacteria that can efficiently degrade both low and highly chlorinated PCBs under aerobic conditions.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.243-249
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• 2005

Citrus juice, a concentrate manufactured by the Jeju Provincial Corporation, was converted into vinegar orderly by alcohol and acetate fermentation. The juice with a 6-fold dilution by distilled water was used as the sole nutrient source throughout the experiments. The diluted juice contained 12.96Brix of total sugar, $0.632\%$ of total acid and $20.23{\mu}g/ml$ of hesperidin. Naringin was not detected from the juice. Citrus wine having $5.6\~6.3\%$ alcohol was produced from the diluted juice after 3 days of fermentation at $28^{\circ}C$. A kind of citrus-malomelo-yeast CMY-28 was used for the wine fermentation. The wine was successfully fermented for 8 days at $30^{\circ}C$ after inoculation of seed vinegar which contained active cells of acid producing bacteria CV1. The inoculum size of the seed vinegar was controlled to $10\%$(v/v) of the citrus wine. The wine was converted into vinegar by the fermentation process. Citrus vinegar, the final fermentation product, was colored with very thin, radish-yellow and was transparent. It's acidity ranged between $5.8\~6.2\%$ of that of acetic acid. The vinegar attained the best score by sensory test among several natural fruit vinegars. It was clear from the results that high quality citrus vinegar could be produced from concentrated citrus juice. However, the fermentation conditions should be improved to reduce the amount of reducing alcohol.

• The Korean Journal of Mycology
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• v.47 no.3
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• pp.199-208
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• 2019

In this study, the community structures of the ectomycorrhizal (ECM) fungi in the roots of Abies koreana and Taxus cuspidata were investigated at different altitudes of Mt. Halla. We identified the collected ECM root tips based on morphological characteristics and phylogenetic analysis through sequencing of the rDNA ITS regions. From the roots of A. koreana and T. cuspidata, 11 species and 12 species were identified, respectively. The Shannon's index and species evenness and abundance of the ECM fungi were higher in the higher than lower regions, regardless of host plant species, however, the number of ECM root tips showed the opposite pattern. The community similarity among the ECM fungi in A. koreana was significantly higher than that among the ECM fungi in T. cuspidata or than that between A. koreana and T. cuspidata (p < 0.05). These results could be useful for the conservation and management of the habitat of A. koreana, which is threatened with extinction due to increasing ambient air temperature.

• Journal of Mushroom
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• v.19 no.1
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• pp.66-70
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• 2021

We monitored the occurrence of fungal species on bed-logs inoculated with oak mushroom (Lentinula edodes) and the environmental conditions of temperature and humidity in the cultivation houses during monsoon. Six fungal species, viz., Cladosporium sp., C. cladosporioides, C. anthropophilum, Pleosporales sp., Trichoderma harzianum, and Acremonium sp., wereidentified from the cultivation houses located in Jangheung, Jeonnam province. This identification was confirmed by performing nucleotide sequence analysis of the internal transcribed spacer and 28S rDNA regions. Our study presents significant findings that can help in preventing fungal damage induced by inappropriate temperature and humidity in oak mushroom cultivation houses.

• Mycobiology
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• v.48 no.6
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• pp.450-463
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• 2020

The strains 17E-042, 17E-039, and NC13-171 belong to Ascomycota and were isolated from soil collected from Sancheong-gun and Yeongam-gun, Korea. The strain 17E-042 produced white mycelial colonies that developed a sienna color with a round margin on potato dextrose agar (PDA), and the reverse side developed a light sienna color. Morphologically, this strain was similar to the strains of Arthrinium phragmites and A. hydei, but the shorter conidial size of the newly identified strain (17E-042) was distinct. The strain 17E-039 produced macroconidia that were pale yellow to orange-brown, elongated-ellipsoid to oblong, round at both ends, primarily straight but sometimes slightly curved, 0-septate, thin-walled, and filled with numerous droplets, having diameters of 20.4-34.3 × 8.0-12.0 ㎛. And the strain NC13-171 formed hyaline to light brown chlamydospores, solitary or in a chain. Multigene phylogenetic analyses were conducted using sequence data obtained from internal transcribed spacer (ITS) regions, 28S rDNA large subunit (LSU), β-tubulin (TUB2), translation elongation factor 1-alpha (TEF1-α), and RNA polymerase II large subunit (RPB2) genes. The results of molecular phylogeny, the detailed descriptions and illustrations of each species strongly support our proposal that these strains from soil in Korea be designated as Arthrinium minutisporum sp. nov. and two new records of Pezicula neosporulosa and Acrocalymma pterocarpi.