• Korean Journal of Microbiology
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• v.50 no.4
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• pp.351-359
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• 2014

A beverage was produced by the fermentation of mixed extracts from the various fruits, vegetables, algae, and medical herbs. The physicochemical properties of the fermented beverage of plant extracts (FBPE) and microbial diversity were analyzed in cultures enriched from FBPE using 16S and 26S rRNA gene sequence analyses. The pH, acidity, $^{\circ}brix$, reducing sugar, and alcohol contents of the FBPE were determined to be the 3.48, 1.68%, 70.0, 1,026 g/L, and 3.5%, respectively. The most abundant free sugar and organic acid in the FBPE were glucose (567.83 g/L) and tartaric acid (93.68 mg/L), respectively. Lactobacillus homohiochii was the predominant species in all enriched culture samples: 100% of the species in 0B (0% sugar) and 40B (40% sugar) libraries and 95.6% of 20B library (20% sugar). Lactobacillus fructivorans was detected in the 20B library. The predominant species in the samples of enrichment cultures collected from FBPE with three different sugar concentrations were: Candida zeylanoides (45.2%) in the 0Y library (0% sugar), Candida lactis-condensi (35.7%) and C. zeylanoides (35.7%) in the 20Y library (20% sugar), and C. lactis-condensi (38.1%) in the 40Y library (40% sugar). This result may provide a useful frame of reference for further analyses of microbial population dynamics in FBPE.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.113-119
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• 2003

Soybean sprout pathogenic bacteria were isolated from the large, deep containers of a commercial factory. Over a period of one year, 40 pathogenic-like bacteria were isolated among a total of 732 isolates. In addition to bacteria previously reported to be associated with rotting, such as Pseudomonas putida and Erwinia carotovora, several other genera were also identified: Acinetobacter spp., Chryseobacterium spp., Klebsiella sp., Pantoea agglomerans, Bacillus sp. Fatty acid methyl ester (FAME) analysis using the Microbial ID (MIDI) system, and 16s rRNA sequence analysis, yielded identical results, confirming the identities of these microorganisms. Several types of selective media were not good for identification and determination of population structure in commercial environments, as colony type was not specific to the genus. There was no dominant bacterium, and we were not able to find the main bacterium responsible for soybean spout rot. Even though we did not identify a major target for controlling rot or screening for resistant cultivars, the results of this study indicated that bacterial rot of soybean sprout is endemic. In addition, it emerged that factory epidemics in summer are not caused by the bacteria isolated in this study.

• Journal of Life Science
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• v.28 no.9
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• pp.1118-1126
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• 2018

In this study, investigated the general characteristics and diagnostic methods types of streptococcosis among various fish disease pathogens that caused a lot of economic damaged to aquaculture fish based on the previous research paper. Streptococcosis infection of fish is considered a reemerging disease affecting a variety of wild and cultured fish throughout the world. Calssifiacation of Gram positive cocci based on DNA-DNA hybridization coupled with 16S sequencing has shown that at least five different species are considered of significance as fish pathogens: Lactococcus garvieae, L. piscium, Streptococcus iniae, S. agalactiae, S. paruberis, Vagococcus salmoninarum. Symptoms of infection with streptococcosis disease such as body color change, eyeball abnormality, gill discoloration, bleeding, abdominal distension, swelling of the kidney and spleen. In addition, it usually occurs from June to October when the water temperature rise a lot of fish death. Currently, 16S rRNA, 16S-23S rRNA intergenic spacer region (ISR), Random Amplified polymorphic DNA (RAPD), Ribotyion (RT), Loop-mediated isothermal amplification (LAMP) are among the methods for diagnosing streptococcosis. Among them, the LAMP method, which is high applicable to the aquaculture farm has attracted the spotlight, but due to problems such as confirmation of results. This seems to minimize the economic loss of streptococcosis which complements the problem so that it can be easily used from the diagnosis to the results confirmation.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.328-336
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• 2022

Aptamers are short, chemically synthesized, single-stranded DNA or RNA oligonucleotides that fold into unique three-dimensional structures. In this study, we aim to determine the antibiofilm activity and binding specificity of the six polyclonal DNA aptamers (S15K3, S15K4, S15K6, S15K13, S15K15, and S15K20) on Staphylococcus aureus BPA-12 and Escherichia coli EPEC 4. Aptamer S15K6 showed the highest percentage of antibiofilm activity against S. aureus BPA-12 (37.4%) as shown by the lowest OD570 value of 0.313. Aptamer S15K20 showed the highest percentage of antibiofilm activity against E. coli EPEC 4 (15.4%) as shown by the lowest OD570 value of 0.515. Aptamers S15K13 and S15K20 showed antibiofilm activities against both S. aureus BPA-12 and E. coli EPEC4, and thus potentially have broad reactivity. Furthermore, based on the binding capacity and Kd values from our previous study, the binding specificity assay of selected polyclonal DNA aptamers (S15K3 and S15K15) against S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, S. agalactiae, E. coli MHA-6, and Listeria monocytogenes were performed using qPCR. Aptamers S15K3 and S15K15 showed specific binding to S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, and S. agalactiae, but could not bind to E. coli MHA-6 and L. monocytogenes. Therefore, this study showed that the polyclonal DNA aptamers have antibiofilm activity and were able to bind to S. aureus BPA-12 and E. coli EPEC 4 bacteria.

• 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%.

• Journal of Life Science
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• v.18 no.12
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• pp.1723-1727
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• 2008

Chlorella sp. CMS-1 strain was isolated from the outdoors cultivation pools in Culmansa Co., Ltd. This strain was found to be a rounded type of 3 ${\mu}m$. Phylogenetic analysis by the 18S rRNA sequencing using isolated strain is most similar to Chlorella sp. IFRPD 1018 gene at the level of nucleotide sequence identity at 99%. Accordingly, the isolated Chlorella strain was named as Chlorella sp. CMS-1 based on its morphological and phylogenetic properties. The concentrations of crude protein and fat were 59% and 0.01%, respectively. Major compositional amino acids (mg%) were glutamic acid 6.21, alanine 5.76, aspartic acid 5.44%, glycine 4.29%, and threonine 3.09% and major free amino acids (mg%) were ${\gamma}$-aminobutyric acid (GABA) 7.13%, L-alanine 1.44%, L-glutamic acid 0.90, L-leucine 0.26% and L-glycine 0.20%. The concentrations of major minerals were P 2.25%, K 2.25%, Na 1.09%, Mg 0.63%, and Ca 0.28%.

• Journal of Microbiology and Biotechnology
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• v.20 no.7
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• pp.1128-1133
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• 2010

The diversity and abundance of ammonia-oxidizing bacteria (AOB) in activated sludge were compared using PCR-DGGE and real-time PCR assays. Activated sludge samples were collected from five different types of wastewater treatment plants (WWTPs) mainly treating textile, paper, food, and livestock wastewater or domestic sewage. The composition of total bacteria determined by PCR-DGGE was highly diverse between the samples, whereas the community of AOB was similar across all the investigated activated sludge. Total bacterial numbers and AOB numbers in the aerated mixed liquor were in the range of $1.8{\times}10^{10}$ to $3.8{\times}10^{12}$ and $1.7{\times}10^6$ to $2.7{\times}10^{10}$ copies/l, respectively. Activated sludge from livestock, textile, and sewage treating WWTPs contained relatively high amoA gene copies (more than $10^5$ copies/l), whereas activated sludge from food and paper WWTPs revealed a low number of the amoA gene (less than $10^3$ copies/l). The value of the amoA gene copy effectively showed the difference in composition of bacteria in different activated sludge samples and this was better than the measurement with the AOB 16S rRNA or total 16S rRNA gene. These results suggest that the quantification of the amoA gene can help monitor AOB and ammonia oxidation in WWTPs.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.345-363
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• 2023

The genus Desmodesmus (Chodat) S.S. An, T. Friedl & E. Hegewald is ubiquitous in freshwater ecosystems, such as rivers, ponds, and wetlands. The actual species diversity and distribution of the genus is unknown because of morphological plasticity affected by habitats. Currently, 38 Desmodesmus species have been reported in Korea most of which transferred from the genus Scenedesmus recently, however, no phylogenetic relationships have been studied yet. Despite the challenges in analyzing relationships among Desmodesmus species through the morphology, ecology, and original description, this study focused on examining species-level relationships using the FBCC culture strains isolated from Korea. A total of 299 sequences (66 of 18S rRNA, 47 of atpB, 67 of petA, 52 of rbcL, and 67 of tufA) were newly determined and used for phylogenetic analysis. Four plastid genes tend to have higher variation than 18S rRNA in the variable sites and P-distance. From the combined phylogeny, the Desmodesmus included six clades such as Clade-1: D. pseudoserratus and D. serratus, Clade-2: D. communis, D. dispar, D. maximus, D. pannonicus, unidentified Desmodesmus sp., Clade-3: D. bicaudatus and D. intermedius, Clade-4: D. microspina, D. multivariablis, D. pleiomorphus, D. subspicatus, Clade-5: D. abundans, D. kissii, and D. spinosus, and Clade-6: D. armatus, D. armatus var. longispina, D. opoliensis, unidentified Desmodesmus spp. The new sequence data from FBCC strains will be used to identify species and study the molecular ecology of scenedesmacean green algae in freshwater ecosystems. The phylogenetic information from this study will expand our understanding of Desmodesmus species diversity in Korea.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.881-884
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• 2000

A polymerase chain reaction (PCR) was performed to rapidly identify Lactobacillus plantarum from type strains and kimchi samples. The PCR experiments were carried out using specific oligonucleotide primer sets based on the 16S rRNA gene sequences of L. plantarum. The expected DNA amplificate of 419 bp was obtained when either purified DNA or whole cells of L. plantarum strains reacted with LP primers, yet not with any of the other strains. The PCR product was confirmed by DNA sequencing. Accordingly, since the PCR method used is simple, specific, and rapid, it will be useful for monitoring and evaluation L. plantarum in the mixed microbial population found in kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.627-632
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• 2013

High levels of an extracellular phytase were isolated from kimchi and found to be produced from a bacterial strain of Lactobacillus sakei (designated as L. sakei Wikim001). Phytase activity was measured from liberated inorganic phosphate obtained by a modification of the ammonium molybdate method using brown rice. Phytase activity was also detected in the culture broth supernatant at the stationary phase. The highest levels of phytase activity from L. sakei Wikim001 were detected at pH 5.0~6.5 and $30{\sim}40^{\circ}C$.