• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.340-346
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• 2014

In this study, the detection method was developed using real-time PCR to distinguish 4 species (bovine, porcine, horse, and chicken) of raw meats. The genes for distinction of species about meats targeted at 12S rRNA and 16S rRNA parts in mitochondrial DNA. Probes were designed to have a 5' FAM and a TAMRA at the 3' end. This study is to develop 4 species-specific primer and probes about raw materials and real-time PCR on 10 strains to observe the products of non-specific signal for similar species. As a result, any non-specific signal were not detected among each other. Real-time PCR method was developed for quantitation and identification of intentional and unintentional mixture in ground mixed meat (The difference of $C_T$ value between intentional mixture and 100% meat: $${\leq_-}$$ cycles, The difference of $C_T$ value between unintentional mixture and 100% meat: $${\geq_-}$$ cycles). The detection and differentiation of intentional and unintentional mixture in this study would be applied to food safety management for eradication of adulterated food distribution and protection of consumer's right.

• Journal of Life Science
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• v.24 no.5
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• pp.522-531
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• 2014

Seasonal variations in the bacterial community of Gwangyang Bay seawater were analyzed using both isolation and cultivation-independent methods. Amplified rDNA restriction analysis was applied to 200 bacterial isolates. Bacterial isolates were composed of four phyla: Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. Pyrosequencing was conducted, in addition to denaturing gradient gel electrophoresis (DGGE) of genomic DNA extracted directly from the water samples. The bacterial sequences obtained by pyrosequencing of 16S rRNA genes consisted of 24 phyla in the spring and summer, 39 in the fall, and 32 in the winter. The diversity index was high in the fall, whereas the dominancy index was high in the spring. In the spring, phylum Firmicutes was dominant, whereas phylum Proteobacteria dominated in the other three seasons. The second most dominant phyla were Proteobacteria in the spring, Firmicutes in the summer, and Bacteroidetes both in the fall and winter. Bacilliaceae was the most predominant family in the spring. Rhodobacteraceae and Bacilliaceae dominated in the summer, and Rhodobacteraceae dominated in the winter. Neither was dominant in the fall Twenty-seven bands purified from DGGE profiles were cloned and analyzed phylogenetically. In the spring, phylum Firmicutes dominated, followed by Proteobacteria. Proteobacteria dominated in all other seasons. Thus, two cultivation-independent methods for determination of seasonal variation patterns at the phylum level were in accordance with each other.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.289-292
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• 2018

Using pyrene as the enrichment nutrient, a bacterial strain 10PY1A, was isolated by enrichment culture from oil-contaminated sea sand of Arabian Gulf in Saudi Arabia, and this strain belongs to the species Idiomarina piscisalsi, based on 16S RNA gene sequence analysis. The genome of I. piscisalsi strain 10PY1A contains 2,346 protein-coding sequences and an average GC content of 47.4% in its chromosome (2.59 Mbp). Genes encoding proteins related to the degradation of pyrene were existed in the strain 10PY1A genome, indicating that this strain can be used to degrade polycyclic aromatic hydrocarbons in oil-contaminated marine flora and soil.

• Journal of Life Science
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• v.27 no.5
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• pp.567-574
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• 2017

This study is to isolate and identify ${\gamma}$-amino butyric acid (GABA) producing lactic acid bacteria (LAB) from Makgeolii, traditional Korean rice wine and then establish the optimal culture conditions for GABA production. Sixty four LAB from Makgeolli were isolated according to the characteristics of the shape and color of the colony grown on MRS agar plate. The GABA production of the isolated strain cultured in MRS broth contained 1% MSG (mono-sodium glutamate) were determined and evaluated by TLC and HPLC analysis. Strain B-134 was selected for highest GABA production. From the analysis of 16S rRNA and glutamate decarboxylase B (gadB) gene sequences, strain B-134 was tentatively identified as a Lactobacillus plantarum subsp. plantarum B-134. Effects of culture parameters, including glutamic acid level, culture temperature, NaCl level, and pH on GABA production were investigated for culture optimization. The optimum culture condition for GABA production by B-134 were culture temperature of $37^{\circ}C$, pH of 5.7, NaCl content of 0% (w/v) and MSG content of 3% (w/v), which produced 25 mM of GABA during cultivation time of 48 hr. From these results, strain B-134 is expected to be utilized as useful microorganisms for GABA-enriched health beneficial food.

• Research in Plant Disease
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• v.27 no.4
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• pp.180-186
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• 2021

Typical bacterial symptoms, water-soaking brown and black leaf spots with yellow halo, were observed on watermelon seedlings in nursery and field of Gyeongnam and Jeonnam provinces. Bacterial isolates from the lesion showed strong pathogenicity on watermelon and zucchini. One of them was rod-shaped with 4 polar flagella by observation of transmission electron microscopy. They belonged to LOPAT group 1. The phylogenical trees with nucleotide sequences of 16S rRNA and multi-locus sequencing typing with the 4 house-keeping genes (gapA, gltA, gyrB, and rpoD) of the isolates showed they were highly homologous to Pseudomonas syringae pv. syringae and grouped together with them, indicating that they were appeared as P. syringae genomospecies group 1. Morphological, physiological, and genetical characteristics of the isolates suggested they are P. syringae pv. syringae. We believe this is the first report that P. syringae pv. syringae caused leaf spot disease on watermelon in the Republic of Korea.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.394-403
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• 2023

In the pursuit of sustainable and environmentally-friendly agricultural practices, we conducted an extensive study on the rhizosphere bacteria inhabiting soils that have been devoid of chemical fertilizers for an extended period exceeding 40 years. Through this investigation, we isolated a total of 80 species of plant growth-promoting rhizosphere bacteria and assessed their potential to enhance plant growth. Among these isolates, Burkholderia cepacia CD2 displayed remarkable plant growth-promoting activity, making it an optimal candidate for further analysis. Burkholderia cepacia CD2 exhibited a range of beneficial characteristics conducive to plant growth, including phosphate solubilization, siderophore production, denitrification, nitrate utilization, and urease activity. These attributes are well-known to positively influence the growth and development of plants. To validate the taxonomic classification of the strain, 16S rRNA gene sequencing confirmed its placement within the Burkholderia genus, providing further insights into its phylogenetic relationship. To delve deeper into the potential mechanisms underlying its plant growth-promoting properties, we sought to confirm the presence of specific genes associated with plant growth promotion in CD2. To achieve this, whole genome sequencing (WGS) was performed by Plasmidsaurus Inc. (USA) utilizing Oxford Nanopore technology (Abingdon, UK). The WGS analysis of the genome of CD2 revealed the existence of a subsystem function, which is thought to be a pivotal factor contributing to improved plant growth. Based on these findings, it can be concluded that Burkholderia cepacia CD2 has the potential to serve as a microbial fertilizer, offering a sustainable alternative to chemical fertilizers.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.217-224
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• 2016

Acinetobacter baumannii (A. baumannii) is prevalent in hospital environments and is an important opportunistic pathogen of nosocomial infection. It is known that this pathogen cause herd infection in hospitals, and the mortality rate is remarkably higher for patients infected with this pathogen and already have other underlying diseases. Herein, we investigated the antibiotic resistance rate and the type of resistance genes in 85 isolates of multi-drug resistant A. baumannii from the samples commissioned to laboratory medicine in two university hospitals-in hospital A and hospital B-located in Cheonan and Chungcheong provinces, respectively, in Korea. As a result, $bla_{OXA-23-like}$ and $bla_{OXA-51-like}$ were detected in 82 stains (96.5%). These 82 strains of $bla_{OXA-23-like}$ producing A. baumannii were confirmed with the ISAba1 gene found at the top of the $bla_{OXA-23-like}$ genes by PCR, inducing the resistance against carbapenemase. The armA, AME gene that induces the resistance against aminoglycoside was detected in 34 strains out of 38 strains from Hospital A (89.5%), and in 40 strains out of 47 strains from Hospital B (85.1%), while AMEs were found in 33 strains out of 38 strains from Hospital A (70.2%) and in 44 strains out of 47 strains in Hospital B (93.6%). Therefore, it was found that most multi-drug resistant A. baumannii from the Cheonan area expressed both acethyltransferase and adenyltransferase. This study investigated the multi-drug resistant A. baumannii isolated from Cheonan and Chungcheong provinces in Korea, and it is thought that the results of the study can be utilized as the basic information to cure multi-drug resistant A. baumannii infections and to prevent the spread of drug resistance.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• Parasites, Hosts and Diseases
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• v.35 no.3
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• pp.203-210
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• 1997

The difrrrenlial display reverse transcription polymerase chain reaction (DDRT-PCR) aniilysis roils performed to identify the pathogellir strain specific amplicons. mRNAs were purified from the trophozoites of the pathogenif strain YS-27 and the non-pathogenic strain S 16. respectively. Three kinds of rirsl stranded rDNAs were reverse transcribed from the mRNAs by one base anchored oligo-dT 11M (M: A. C, or G) primers. Each cDNA lemplatr was used for DDRT-PCK analysis. A total of 144 pathogenic strain specific amplicons was observed in DDRT-PCR analysis using primer combinations of the 11 arbitrary primers and the 3 one base anchored oli해-dT11M primers. Of these 31 amplit'tons were verified as the amplirons amplified only from the mRNAs of the pathogenic strain by DNA slots biol llybridizatioil. Furthel cklaracleization of the 31 pathogenic strain sprcifil amplicons by DNA slot blot hybridlnation analysis using biotin labeled Probes or the PCR amplified DNA of rysteine proteinase genes revealed that 21 of them were amplliried from the maNAs of the cysteine proteinase genes. Four randomly selected amplirons out of the rest 10 amplirons were used fur screening of cDNA library followed by immunoscreening and all of them were turned outs to be amplified from the mRNA.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.242-250
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• 2017

Actinobacteria tolerating extreme conditions can be a rich source of bioactive compounds and enzymes. In this study filamentous actinobacteria were isolated from soils of Ulleung Island, and their physiological properties were examined. Soil samples were collected, serially diluted and spread on various agar media. The average viable counts of total bacteria were $1.28{\times}10^7CFU/g$ for soil sample 1 (ULS1) and $2.05{\times}10^7CFU/g$ for soil sample 2 (ULS2). As a result, 34 strains of actinobacteria were isolated and assigned to the genera Streptomyces (16 strains), Isoptericola (5 strains), Rhodococcus (4 strains), Agromyces (3 strains), Micrococcus (2 strains), Arthrobacter (1 strain), Williamsia (1 strain), Microbacterium (1 strain), and Oerskovia (1 strain) based on 16S rRNA gene sequence analysis. Enzyme activity and plant growth promoting potential were tested for representative isolates. Multiple strains of Streptomyces degraded starch, casein and Tween 80. As for plant growth promoting potential, strains of Oerskovia, Williamsia, Isoptericola, and Streptomyces solubilized phosphate, and those of Agromyces, Oerskovia, Micrococcus, Rhodococcus, Streptomyces, and Isoptericola produced 3-indole-acetic acid (IAA), respectively. Selected strains of Streptomyces exhibited strong antagonistic activity against Staphylococcus aureus and Bacillus subtilis as well as Candida albicans. This study confirms that actinobacteria from Ulleung Island can be a good source of novel bioactive compounds.