• The Korean Journal of Ecology
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• v.21 no.5_2
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• pp.575-583
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• 1998

Physicochemical factors, microbial population size and the properties of the bacterial isolates were assessed to find out the nature of soil ecosystem of Mt. Paektu. Samples were obtained from the surface layer of soils on which specific plant community is developed. Average content of moisture, organic matter and avaiable phosphate of the soils were 21.6%, 17.3% and 2.48mg/100g, respectively. These values were similar to those of developing forest soils, but were slightly lower than those of climax ecosystem such as Piagol in Mt. Chiri. The population size of soil bacteria ranged from 2.7 to $202.5{\times}10^5$ CFU/g.dry soil, and the size is somewhat dependent on the content of moisture and oranic matter of the forest soil. A large number of bacteria was able to decompose macromolecules such as starch, elastin and gelatin. While the distribution rate of resistant bacteria to antibiotics was high, that to toxic chemicals was low. This means that the competition between microorgani는 predominate over the interference with artificial behaviour such as spread of pesticides in the surveyed region. Bacterial species composition of each soil was comparatively simple. Pseudomonas, Agrobacterium, Flavobacterium and Xanthomonas which are Gram-negative short rods were widely distributed in the forest soils. The endospore forming Bacillus species were also main constituents of the soil microflroa. any one of the strains was not identified as Azospirillum or Micrococcus which are known to be one of major constituents of the forest soil. for the correct identification of isolates chemotaxonomic studies will be proceeded, and the strains are to be stored in the Type collection Center.

• Journal of fish pathology
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• v.3 no.1
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• pp.1-9
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• 1990

The present study was carried out to reveal the characteristics of organism responsible for so called vibriosis prevailing in warm water season among cultured kuruma prawn Penaeus japonicus. A bacterium was isolated from the heart, lymphoid organ and muscle of the diseased kuruma prawn. Six strains obtained from diseased kuruma prawn in some culture farms in Namhae and Anhung from august to october in 1989 were submitted to the morphological, biochemical and physiological characterization. All the strains were gram-negative, nonsporning short rods with one polar flagellum. Glucose was fermented with no gas production by these strains. Some distinguishing features of the organisms were negative to lysine, arginine, ornithine decarboxilization test. In general, the temperature $20{\sim}27^{\circ}C$, the NaCl concentration of 2~3% and pH of 6~8 were optimal for the growth in peptone water. The organisms were sensitive to the vibrio static agent 0/129. The isolated should be identified as Vibrio sp.. No essential differences in histopathological finding were noted between the naturally and the experimentally infected prawns. Most characteristic pathological changes were extensive necrosis caused by severe bacteria invasion and multiple formation of meranized nodules in the lymphoid organ.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1210-1217
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• 2021

Two gram-negative, catalase-positive, strictly aerobic, and white colony-forming bacteria, strains H242^T and B156^T, were isolated from soil in South Korea. Cells of strain H242^T were oxidase-positive and non-motile short rods, while those of strain B156^T were oxidase-negative and long non-motile rods. Ubiquinone-8 was identified as the sole isoprenoid quinone in both strains. C_16:0, cyclo-C_17:0, andsummed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were identified in both strains as the major cellular fatty acids and polar lipids, respectively. The DNA G+C contents of strains H242^T and B156^T were 69.4 mol% and 69.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA and 92 concatenated core gene sequences revealed that strains H242^T and B156^T formed distinct phylogenic lineages from other Ramlibacter type strains. The DNA-DNA hybridization (DDH) value between strains H242^T and B156^T was 24.6%. Strains H242^T and B156^T were most closely related to Ramlibacter ginsenosidimutans BXN5-27^T and Ramlibacter monticola G-3-2^T with 98.4% and 98.6% 16S rRNA gene sequence similarities, respectively. Digital DDH values between strain H242^T and R. ginsenosidimutans and between strain B156^T and R. monticola were 23.5% and 26.1%, respectively. Phenotypic, chemotaxonomic, and molecular analyses indicated that strains H242^T and B156^T represent two novel species of the genus Ramlibacter, for which the names Ramlibacter terrae sp. nov. and Ramlibacter montanisoli sp. nov., respectively, are proposed. The type strains of R. terrae and R. montanisoli are H242^T (=KACC 21667^T=JCM 33922^T) and B156^T (=KACC 21665^T=JCM 33920^T), respectively.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.361-365
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• 2016

This study was conducted to isolate and identify a microorganism that increases tricin-O-(threo-${\beta}$-guaiacylglyceryl) ether (TTGE) content in the hulls of rice (Oryza sativa L.). Bacteria from germinated rice were isolated by enrichment cultivation using yeast mold, luria bertani, potato dextrose and mannitol egg york polymyxin broths. The highest increase in TTGE content ($339.30{\mu}g/g$) was achieved by a microorganism isolated by PDA enrichment cultivation. On the basis of 16S RNA sequence homology and phylogenetic analysis, the isolated bacterium was identified to have 100% similarity with Burkholderia vietnamiensis. The isolated bacteria were short rods, negative for the Gram stain, and positive for the catalase test. The highest TTGE level was $435.86{\mu}g/g$ in 72-h fermented samples, representing a 2.5x increase compared with the control ($175.65{\mu}g/g$). In conclusion, the bacterium isolated from germinated rice extract was Burkholderia vietnamiensis, and the optimum fermentation period to maximize TTGE levels was 72 h. These findings might help in developing functional materials using rice hulls, a waste product of rice milling.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.219-226
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• 2015

Acetic acid bacteria (AAB) were isolated from vinegar fermented through traditional methods in Namhae county, Gyeongnam, the Republic of Korea. The isolated strains were Gram negative, non-motile, and short-rods. Three selected strains were identified as either Acetobacter pasteurianus or Acetobacter aceti by 16S rRNA gene sequencing. A. pasteurianus NH2 and A. pasteurianus NH6 utilized ethanol, glycerol, D-fructose, D-glucose, D-mannitol, D-sorbitol, L-glutamic acid and Na-acetate. A. aceti NH12 utilized ethanol, n-propanol, glycerol, D-mannitol and Na-acetate. These strains grew best at 30℃ and an initial pH of 3.4. They were tolerant against acetic acid at up to 3% of initial concentration (v/v). The optimum conditions for acetic acid production were 30℃ and pH 3.4, with an initial ethanol concentration of 5%, resulting in an acetic acid concentration of 7.3−7.7%.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.97.1-97
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• 2003

An antagonistic bacterium, KJ1R5,, to Phytophthora capsici was obtained from root interior of a healthy pepper plant. To identify the bacterial antagonist, 16S rDNA sequence analysis, Biolog system, fatty acid methyl-esters (FAMEs), and physiological and biochemical characterization were conducted. The determined 165 rDNA sequence of KJ1R5, showed higher similarities to those of a group consisting of several Chryseobacterium strains with 95.2, 95.2, and 95,1％ similarity to C. defluvii, Chryseobacterium sp. FR2, and C. scophthalmum, respectively, In addition, Halounella gailinarum, Bergeyella zoohelcum, and Riemerella anatipestifer are another group for KJ1R5, with 94.1, 89.7, and 87.2％ similarities, respectively When identification of the antagonistic bacterium, KJ1R5, was conducted using BIOLOG system, the strain KJ1R5, was identified as Flavobacterium tirrenicum (similarity； 0.75％). Fatty acid profiles of the strain KJ1R5, were composed mainly of iso-17：0 w9c and iso-15：0 and identified as Chryseobacterium balustinum (similarity 0.524％). KJ1R5, was Gram-negative, regular short rods ranging from 0.8 $\mu\textrm{m}$ to 1.0 $\mu\textrm{m}$ and had no flagella. Phenotypic characterization of the antagonistic bacterium indicated that KJ1R5, were included in the genus Chreseobacterium, which belongs to the family Flavobacteriaceae. The strain was distinguished from these six existing species. These results indicated that strain might be placed as a new species in the genus Chryseobacterium.

• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.5-10
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• 2009

A freshwater bacterium, designated $IMCC1713^T$, was isolated from a highly eutrophic artificial pond. Cells of the strain were Gram-negative, chemoheterotrophic, poly-$\beta$-hydroxybutyrate granule containing and obligately aerobic short rods that were motile with a single polar flagellum. The 16S rRNA gene sequence similarity analysis showed that the novel strain was most closely related to the species Roseateles depolymerans (96.3%), Mitsuaria chitosanitabida (96.2%), Ideonella dechloratans (96.2%), and Pelomonas saccharophila (96.1%) in the Sphaerotilus-Leptothrix group within the order Burkholderiales. Phylogenetic trees based on 16S rRNA gene sequences indicated that the isolate formed an independent monophyletic clade within the order Burkholderiales. The relatively low DNA G+C content (57.4mol%), together with several phenotypic characteristics, differentiated the novel strain from other members of the Sphaerotilus-Leptothrix group. From the taxonomic data, therefore, the strain should be classified as a novel genus and species, for which the name Inhella inkyongensis gen. nov., sp. nov. is proposed. The type strain of the proposed species is strain $IMCC1713^T$ (=KCTC $12791^T$=NBRC $103252^T$=CCUG $54308^T$).

• The Korean Journal of Ecology
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• v.21 no.5_3
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• pp.703-712
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• 1998

Physicochemical factors, microbial population size and the properties of the bacterial isolates were estimated to find out the nature of soil ecosystem of Mt. Nam. Samples were obtained from the surface layer of soils on which specific plant community is developed. Average content of moisture and organic matter of the soils were 21.6% and 17.3%, respectively. These values were similar to those of developing forest soils, but were slightly lower than those of climax ecosystem such as Piagol in Mt. Chiri. Chiri. Content of phosphate was higher than those of other forest soils. The population size of soil bacteria ranged from 27.4 to 195.8 ${\times}\;10^5$ CFU/g. duy soil, and the size is somewhat dependent on the moisture and oranic matter content of soils. A large number of bacteria were able to decompose macromolecules such as starch, elastin and gelatin. Bacterial species composition of each soil was comparatively simple. Pseudomonas, Agrobacterium, Flavobacterium and Xanthomonas which are Gram-negative short rods were widely distributed in the forest soils. The endospore forming Bacillus species were also the main constituents of the soil microflroa. Actinomycetes were widely distributed in the forest soils, but the distribution pattern varied in each site. Most of the actinomycetes were also able to decompose organic macromolecules. The rate of resistant actinomycete strains to antibiotics and heavy metals were lower than those from cultivated soils, but higher than those from well-preserved forest soils. Antibiosis pattern of the actinomycete isolates was similiar to the resistance pattern. This means the forest soils of Mt. nam was somewhat interferred by artificial behabiour.

• Clinical and Experimental Pediatrics
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• v.64 no.6
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• pp.293-300
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• 2021

Background: Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment. Purpose: This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children. Methods: This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated. Results: A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03). Conclusion: fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1292-1298
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• 2023

PAMB 00755^T, a bacterial strain, was isolated from Korean fir leaves. The strain exhibits yellow colonies and consists of Gram-negative, non-motile, short rods or ovoid-shaped cells. It displays optimal growth conditions at 20℃, 0% NaCl, and pH 6.0. Results of 16S rRNA gene-based phylogenetic analyses showed that strain PAMB 00755^T was most closely related to Sphingomonas chungangi MAH-6^T (97.7%) and Sphingomonas polyaromaticivorans B2-7^T (97.4%), and ≤96.5% sequence similarity to other members of the genus Sphingomonas. The values of average nucleotide identity (79.9-81.3%), average amino acid identity (73.3-75.9%), and digital DNA-DNA hybridization (73.3-75.9%) were significantly lower than the threshold values for species boundaries; these overall genome-related indexes (OGRI) analyses indicated that the strain represents a novel species. Genomic analysis revealed that the strain has a 4.4-Mbp genome encoding 4,083 functional genes, while the DNA G+C content of the whole genome is 66.1%. The genome of strain PAMB 00755^T showed a putative carotenoid biosynthetic cluster responsible for its antioxidant activity. The respiratory quinone was identified as ubiquinone 10 (Q-10), while the major fatty acids in the profile were identified as C_18:1ω7c and/or C_18:1ω6c (summed feature 8). The major polar lipids of strain PAMB 00755^T were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and phosphatidylcholine. Based on a comprehensive analysis of genomic, phenotypic, and chemotaxonomic characteristics, we proposed the name Sphingomonas abietis sp. nov. for this novel species, with PAMB 00755^T as the type strain (= KCTC 92781^T = GDMCC 1.3779^T).