• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.387-394
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• 2007

Despite geographic barriers such as oceans, many freshwater algal species inhabit different continents of the world. A unicellular freshwater alga, Mallomonas caudeata, commonly occurring in Asia, Europe, and America of the northern Hemisphere, is closely related to human life such as monitoring blooms and defecting changes in climates. In order to demonstrate its occurrence in Korea and to infer its phylogeny, we sequenced nuclear SSU and plastid rbcL genes from isolates collected in six different reservoirs. We have also investigated transmission electron microscopy of the Korean isolates. SSU sequences of the species from Korea and USA were almost identical, having pair-wise divergences of 0.06% in SSU and 0.45% in rbcL. Both gene trees revealed that the species was clearly separated from other species of the genus, while the genus was not monophyletic. Rhizoplasts are composed of microfibrils organised in striated rootlets attached to the multilayered plate of basal bodies and arranged on the surface of the nucleus at their distal ends. The rhizoplast constitutes a basal body-nucleus connector similar to that of typical Synurophyceas. The results that Mallomonas was not supported by both SSU and rbeL data sets require a further study with additional taxon sampling.

• Journal of fish pathology
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• v.26 no.3
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• pp.193-206
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• 2013

The ark shell, Scapharca broughtonii is a marine bivalve mollusks belonging to the family Arcidae and important seafood for Korean and Japanese, and southern coast is brisk bays for the ark shell aquaculture. However, productivity of ark shell from these regions were rapidly reduced during the last decade due to mass mortality. The reason of this great damage has not yet been identified. To overcome this economic loss, diverse investigations were focused on environmental factors that affects in the physiology of S. broughtonii, but microbiological researches were performed insufficiently. Hemoglobin is one of the major blood component of ark shell and is damaged by some species of bacterial toxins. We concentrated on this red pigment because hemolysis could be the cause of ark shell mortality. In this study, we analyzed microbial diversity of underwater sediments in coastal regions and also existences in the body of S. broughtonii. We investigate about 4,200 isolates collected from June to September for microbial diversity of sediments and ark shell. We screened all of culturable microorganisms, and identified 25 genera 118 species, 24 genera 89 species, 30 genera 109 species and 39 genera 141 species, and selected 140 unique colonies for identification and challenge assay.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.670-676
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• 2017

Recently, mass mortality of the young abalone Haliotis discus hannai has occurred in commercial seed production farms in Korea. The mortality rate was above 50% of the total cultured organisms in the farm, and the shell length of the moribund organisms was about 3cm. The mortal phenomenon was that the young abalones were weakly scattered on the bottom of the pond from the attachment matrix, or that they could not be moved back to their normal positions. The diseased farmed Pacific abalone had abdominal edema. From the edema in the moribund individuals, three bacterial strains were isolated and all the strains were identified as Vibrio harveyi. These strains were compared with thirty six strains isolated from the fish. The results was that the Vibrio harveyi from the fish were sorted into genogroup A or B; however, the three strains of the diseased farmed Pacific abalone were sorted into genogroup A and the new genogroup C. The identical mortality and pathological symptoms of the naturally infected organisms were reproduced by artificial infection with WA AG-1 and WA CS-5 strains. The $LD_{50}$ of WA AG-1 and WA CS-5 were each $1.0{\times}10^3cfu\;animal^{-1}$ and $1.7{\times}10^4cfu\;animal^{-1}$.

• Korean Journal of Plant Taxonomy
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• v.35 no.1
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• pp.7-23
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• 2005

Molecular phylogenetic studies were conducted to evaluate interspecific relationships in 40 populations of Viola including 35 Korean taxa, four Japanese populations and one outgroup using nuclear ribosomal ITS sequences. The phylogenetic analyses were conducted using parsimony and neighbor-joining methods. Subsection Trigonocarpae of section Nomimium appeared as the most basal clade within the Korean Viola. Section Dischidium and Chamaemelanium was monophyletidbootstrap 100%) and placed between subsect. Trigonocarpae and three other subsections of sect. Nomimium. Sect. Nomimium was paraphyletic. Although each subsectional grouping was in accordance with previous infrageneric classification based on morphological characters, yet discordance remained at the series level. Two evolutionary trends observed in the ITS tree were as follows. First, subsect. Trigonocarpae(x=10) was derived from the outgroup(x=6); Second, subsects. Bilobatae and Vaginatae(x=10 or 12), and subsect. Patellares(x=12) of sect. Nomimium were originated from sects. Dischidium and Chamaemelanium(x=6). Viola albida complex including three very closely related taxa was recognized as independent group within subsect. Patellares in parsimony tree. This result suggested that they should be treated as a taxa in series Pinnatae. Phylogenetic position of a putative hybrid species, Viola woosanensis was not supported with previous morphological hypothesis.

• Food Science and Preservation
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• v.15 no.5
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• pp.774-781
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• 2008

was performed and Staphylococcus sciuri, Bacillus cereus, Escherichia coli, Proteus mirabilis, and Enterococcus faecalis were identified. No Salmonella strain, a typical contaminant of eggs, was found. The radiation sensitivities of isolated bacteria and Salmonella typhimurium, in an inoculated model system, were expressed in $D_{10}$ values. The ranges of $D_{10}$ values shown by S. typhimurium, S. sciuri, B. cereus, E. coli, P. mirabilis, and E. faecalis were 0.365-0.399 kGy, 0.418-0.471 kGy, 1.075-1.119 kGy, 0.280-0.304 kGy, 1.132-1.330 kGy, and 0.993-1.290 kGy, respectively. The growth of all six test bacteria in eggs (inoculated at $10^6-10^7\;CFU/g$) during 3 days of post-irradiation storage at ambient conditions ($25^{\circ}C$) was recorded. S. typhimurium was eliminated by irradiation at 3 kGy, and E. coli and S. sciuri were eliminated by irradiation at 5 kGy. The viable cell counts of B. cereus, P. mirabilis, and E. faecalis in eggs showed 4-6 log reductions after irradiation with 5 kGy.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.409-414
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• 2006

Sulfur-oxidizing bacteria were enumerated and isolated from a steady-state anaerobic master culture reactor (MCR) operated for over six months under a semi-continuous mode and nitrate-limiting conditions using thiosulfate as an electron donor. Most are Gram-negative bacteria, which have sizes up to 12 m. Strains AD1 and AD2 were isolated from the plate count agar (PCA), and strains BD1 and BD2 from the solid thiosulfate/nitrate medium. Based on the morphological, physiological, FAME and 16S rDNA sequence analyses, the two dominant strains, AD1 and AD2, were identified as Paracoccus denitrificans and Paracoccus versutus (formerly Thiobacillus versutus), respectively. From the physiological results, glucose was assimilated by both strains AD1 and AD2. Heterotrophic growth of strains AD1 and AD2 could be a more efficient way of obtaining a greater amount of biomass for use as an inoculum. Even though facultative autotrophic bacteria grow under heterotrophic conditions, autotrophic denitrification would not be reduced.

• Journal of Korean Medicine for Obesity Research
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• v.18 no.2
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• pp.106-114
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• 2018

Objectives: We investigated about the microbial properties and changes in the efficacy of the Codonopsis lanceolata (CL) by natural fermentation. Methods: CL was fermented for four weeks in a well-ventilated place with 2.5% salt. pH, total sugar, total polyphenol, and total flavonoid were measured to determine fermentation characteristics according to fermentation period and salt treatment. Polymerase chain reaction denaturing gradient gel electrophoresis and random amplification of polymorphic DNA-polymerase chain reaction were carried out for microbial analysis during fermentation. In addition, HepG2 cell was cultured to check the lipid accumulation through oil red O staining and the glucose uptake was analyzed by measuring the 2-NBDG at C2C12 cell. Results: The pH level and the total sugar decreased with the CL fermentation. Total polyphenol and flavonoid increased after CL fermentation. It was confirmed that Leuconostoc mesenteroides were maintained continuously during fermentation. In the salt treatment CL, there was a sharp increase in Rahnella aquatilis. Lactobacillus plantarum matrix was observed in fermented CL. In addition, Lactococcus lactis, Weissella koreensis, R. aquatilis, L. plantarum, Leu. mesenteroides have been added to the salt treatment. Glucose uptake were significantly increased after fermentation with salt for four weeks. Lipid accumulation in the HepG2 cells was observed that there was difference (P<0.01) between free fatty acid group (100%) and decreased 4 weeks after fermentation (90.38%) at $800{\mu}g/mL$. Conclusions: Total polyphenol and flavonoid were increased after CL fermentation. Especially, percentage of the glucose uptake and lipid accumulation inhibition increased in CL fermentation with salt. It is expected that fermentation of salt treated CL will be more effective in diabetes and fatty liver.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.

• Journal of Life Science
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• v.31 no.1
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• pp.73-82
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• 2021

Throughout history, barley was the typical crop of the soils of Jeju Island due to its topographical features. People in Jeju eat Shindari or Dansul. Shindari or Dansul is a fermented drink of Jeju, made from the leftovers of cooked barely and nuruk of short fermentation periods. Although Makgeolli and Shindari share a similar fermentation period and materials, research on Shindari or Dansul is still in its early stages. In this study, we examined major bacterial species of Shindari or Dansul. In addition, we confirmed the antibacterial activities of an isolated strain against fish and human-harmful bacteria. Among the isolates, Firmicutes consisted of 73% and the Proteobacteria of 27%, indicating that the Firmicutes phylum was the dominant one. In addition, the Pediococcus genus and the Bacillus genus were the most prevalent consisting of 25%, followed by the Cronobacter genus (25%), the Enterococcus genus (16%), the Aneurinibacillus genus (5%), the Klebsiella genus (4%), and the Paenibacillus genus (2%). We conclude that the Lactobacillus genus predominated in Makgeolli, but the Pediococcus genus predominated in Shindari. In a study of the antibacterial activity, growth inhibition was observed for all bacteria, except for the fish disease bacterium Photobacterium damselae subsp. piscicida and the human-harmful bacterium Streptococcus mutans.

• Obstetrics & gynecology science
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• v.61 no.6
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• pp.662-668
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• 2018

Objective This study was to identify the risk factors for cytological progression in women with atypical squamous cells of undetermined significance (ASC-US) or low-grade squamous intraepithelial lesions (LSIL). Methods We analyzed data from women infected with the human papillomavirus (HPV) who participated in the Korean HPV cohort study. The cohort recruited women aged 20-60 years with abnormal cervical cytology (ASC-US or LSIL) from April 2010. All women were followed-up at every 6-month intervals with cervical cytology and HPV DNA testing. Results Of the 1,158 women included, 654 (56.5%) and 504 (43.5%) women showed ASC-US and LSIL, respectively. At the time of enrollment, 143 women tested positive for HPV 16 (85 single and 58 multiple infections). Cervical cytology performed in the HPV 16-positive women showed progression in 27%, no change in 23%, and regression in 50% of the women at the six-month follow-up. The progression rate associated with HPV 16 infection was higher than that with infection caused by other HPV types (relative risk [RR], 1.75; 95% confidence interval [CI], 1.08-2.84; P=0.028). The cytological progression rate in women with persistent HPV 16 infection was higher than that in women with incidental or cleared infections (P<0.001). Logistic regression analysis showed a significant relationship between cigarette smoking and cytological progression (RR, 4.15; 95% CI, 1.01-17.00). Conclusion The cytological progression rate in HPV 16-positive women with ASC-US or LSIL is higher than that in women infected with other HPV types. Additionally, cigarette smoking may play a role in cytological progression.