• Journal of Species Research
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• 제10권3호
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• pp.191-200
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• 2021

To study the biodiversity of bacterial species, here we report indigenous prokaryotic species of Korea. A total of 23 bacterial strains affiliated to the class Alphaproteobacteria were isolated from various environmental sources including seaweeds, seawater, fresh water, wetland/marsh, tidal sediment, plant roots, sewage and soil. Considering higher than 98.8% 16S rRNA gene sequence similarities and formation of a well-defined phylogenetic clade with named species, it was confirmed that each strain belonged to the predefined bacterial species of the class Alphaproteobacteria. There is no official report of these 23 species in Korea; 20 species of 16 genera (Mameliella, Yangia, Paracoccus, Ruegeria, Loktanella, Phaeobacter, Dinoroseobacter, Tropicimonas, Lutimaribacter, Litoreibacter, Sulfitobacter, Roseivivax, Labrenzia, Hyphomonas, Maricaulis, Thalassospira) in the order Rhodobacterales and 3 species of a single genus (Brevundimonas) in the order Caulobacterales. Gram-staining, cell morphology, basic biochemical characteristics, isolation sources, optimum temperature, growth media, and strain IDs are detailed in the species description as well as Table 1.

• Asian-Australasian Journal of Animal Sciences
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• 제15권7호
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• pp.1057-1065
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• 2002

The antagonistic activities of 30 strains of lactobacilli against Helicobacter pylori were determined and Lactobacillus helveticus CU631 has been selected as the strain which possesses the strongest inhibitory effect in the disc diffusion assay showing inhibition zone diameter of $10{\pm}1.5mm$, whereas those of L. plantarum and L. fermentum have been shown to be $4.0{\pm}0.6mm$. H. pylori G88016 revealed the highest vacuolating toxin producing activity among the 8 strains, the inhibitory activity of L. helveticus CU631 in vacuolating toxin producing activity of H. pylori manifested in the co-culture of two strains and in the 5:5 mixture of supernatant of the two strains. Both L. helveticus CU631 and cell free culture supernatant had a strong inhibitory activities in urease and cytotoxin producing activities of H. pylori NCTC11637 and CJH12. An accelerated proteolytic activity of water soluble peptides by L. helveticus CU631 during the refrigeration storage has been manifested in the cream cheese. DNA seqences of 16S-23S ribosomal RNA spacer region showed typical pattern among the various strains of L. helveticus, which could be used in the identification of L. helveticus CU 631.

• Journal of Species Research
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• 제12권spc2호
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• pp.15-22
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• 2023

During a comprehensive investigation of indigenous prokaryotic species in Korea, 20 and one bacterial strains assigned to the phyla Bacillota and Verrucomicrobiota, respectively, were isolated from diverse environmental habitats, including soil, mud, tidal flat, seawater, sand, sediment, brackish water, and healthy human urine. Based on their high 16S rRNA gene sequence similarities (>98.7%) and the formation of robust phylogenetic clades with their closest related reported species, each strain was assigned to an independent and predefined bacterial species. Since there were no published or official reports regarding these 21 isolates in Korea, they - 20 species of four families in two orders of the phylum Bacillota and one species of the phylum Verrucomicrobiota - have been reported as unrecorded species in Korea. In addition, Gram staining, colony and cell morphology, basic biochemical characteristic, isolation source, and strain ID of each species are also described in the species description sections.

• Journal of Species Research
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• 제12권spc2호
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• pp.33-44
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• 2023

In 2021, a total of 27 bacterial strains were isolated from soil, tree bark, moss, wetland, sea sediment, tidal flat, seawater and seaweed within Republic of Korea. Based on the analysis of 16S rRNA gene sequence (>98.7% sequence similarity), these isolates were assigned to the class Alphaproteobacteria as unrecorded species in Korea. The 27 strains were classified into the 10 families: Maricaulaceae of the order Caulobacterales; Brucellaceae, Methylobacteriaceae, Nitrobacteraceae and Rhizobiaceae of the order Hyphomicrobiales; Micropepsaceae of the order Micropepsales; Rhodobacteraceae of the order Rhodobacterales; Azospirillaceae of the order Rhodospirillales; and Erythrobacteraceae and Sphingomonadales of the order Sphingomonadaceae. There is no official report of these 27 species in Korea. Therefore, we report 27 isolates as unrecorded species, and described isolation sources, Gram-stain reactions, physiological and biochemical properties and morphologies of these strains.

• Fisheries and Aquatic Sciences
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• 제3권1호
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• pp.64-70
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• 2000

DNA probes for the l6S rRNA have been designed for the detection of Edwardsiella tarda. In order to accomplish this purpose, the l6S rRNA gene from E. tarda has been cloned and sequenced. Two highly feasible oligonucleotide probe sites have been determined by the database analysis programs presented by PCGENE and BLAST. These two probes have been evaluated by slot blot hybridization analysis. Hetero- and homo-trimeric templates have been synthesized using these two probe sites. The templates have been further multimerized by PCR to generate between 150 and 300 bp long DIG-11-dUTP labeled probes. Unlike 3' end labeled oligonucleotide probes or templates, multimerized probes showed no cross­hybridization in the given experimental condition. Furthermore, a significant increase in sensitivity has been observed with these probes. This method, we presented here, may be useful for the designing of probes for the detection of other fish pathogenic microorganisms also.

• Proceedings of the SCSK Conference
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.241-242
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• 2003

The effects of N-acetylphytospingosine(NAPS), one of the phytospingosine derivatives, on melanogenesis of B 16F 1 0 mouse melanoma cell lines were investigated. We assessed the effect of NAPS on the depigmentation of B16F10 cells. The melanin content of cells was significantly reduced by NAPS. We examined the inhibitory effect of NAPS on tyrosinase activity using L-dopa as a substrate and the results showed that tyrosinase activity was inhibited in a does-dependent manner. The mRNA level of tyrosinase as well as that of tyrosinase related protein-l (TRP-l) and tyrosinase related protein-2 (TRP-2) genes were not affected by NAPS based on a reverse transcription-polymerase chain reaction (RT-PCR) assay. We also performed a Western blotting analysis using anti-tyrosinase antibody. It showed that there is no change in tyrosinase protein level after treatment of NAPS. These results suggest that the depigmenting mechanism of NAPS in B16F10 melanoma cells involves inhibition of melanosomal tyrosinase activity, rather than the mRNA expression or protein level of tyrosinase.

• Journal of the Korean Society of Food Science and Nutrition
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• 제39권1호
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• pp.47-53
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• 2010

Bacteria strains with high activities of extracellular enzymes (protease, fibrinolytic enzyme, amylase, cellulase, and lipase) were isolated from Jeju traditional fermented soybean paste (Doenjang), and characterized by 16S rRNA gene sequence analysis and physiological properties. Protease activities were higher in JR14, JR19, JR25, JR32, JR38, JR47, and JR64 than Bacillus subtilis KCCM 12027 (standard strain). Amylase activities were shown in JR6, JR25, JR38, JR56 and JR81, while not in KCCM12027. Cellulase activities were higher in JR6, JR14, JR48, and JR65 than those of other isolated strains and KCCM 12027 whereas lipase activities were the higher in JR-14 and JR-48. Thrombolytic activity in JR19 with high hemolysis activity were 192% compared with that of plasmin as a positive control. Zymogram analysis indicated that the thrombolytic active strains had 4~5 bands in the molecular weight range of 25~75 kDa. Gene sequence analysis of rRNA revealed that the isolated stains had 99% homology with Bacillus species, and the thrombolytic active stain JR19 was B. stratosphericus $41KF2a^T$.

• Horticultural Science & Technology
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• 제31권6호
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• pp.657-665
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• 2013

A large patch disease caused by Rhizoctonia solani AG2-2 (IV) is a serious problem in Korean lawngrass (Zoysia japonica) sites including golf courses and sports fields in Korea. Antagonistic microorganisms against R. solani AG2-2 (IV) were isolated from various forest and crop soil sources in Southern Korea. Among the 61 isolates, I-009, FRIN-001-1, and YPIN-022 strains showing dramatic inhibition of the mycelial growth of R. solani AG2-2 (IV) in the pairing culture were selected as the most potential antagonistic microorganisms for this study. Based on the 16s RNA sequence comparison, I-009 and FRIN-001-1 isolates were identified as Bacillus spp., while YPIN-022 isolate belongs to the genus Pseudomonas. The greater inhibition (clear) zone between two edges of the selected and pathogenic microbes ranged from 11 to 15 mm in three selections, but the others averaged to 7 mm out of 30 mm distance. In another antifungal test using culture filtrate, those three isolates represented a range of 51.7 to 63.5% suppression potential. The selected isolates also inhibited significantly the stem-segment colonization by R. solani AG2-2 (IV) in vivo test by 28.1%, 43.0%, and 23.7% when inoculated with I-009, FRIN-001-1, and YPIN-022, respectively. The highest antagonistic activity for the large patch disease was demonstrated by the isolate FRIN-001-1, which will be useful for developing a bio-pesticide against Rhizoctonia.

• Journal of Food Hygiene and Safety
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• 제30권3호
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• pp.281-288
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• 2015

Vibrio is a genus of Gram-negative, curved, halophilic, and non-spore-forming bacteria. Some of the Vibrio species, such as V. cholerae and V. parahaemolyticus, often contaminate seafood products and occasionally cause human diseases when the seafood products are ingested. A total of 24 Vibrio strains were isolated from shrimp samples on Thiosulphate citrate bile salt sucrose (TCBS) media in this study. All of the 24 isolates were confirmed to belong to the genus Vibrio by using 16S rRNA gene sequence analyses. Vitek 2 system and species-specific polymerase chain reaction (PCR) methods were used to further identify a total of 29 Vibrio strains at the species level, including the 24 shrimp Vibrio isolates and five Vibrio reference strains. The specificities of the two methods to identify Vibrio strains at the species level were compared in this study. The species-specific PCR method was designed to detect five different Vibrio species, such as Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio alginolyticus, and Vibrio mimicus. From the 24 Vibrio shrimp isolates, the Vitek 2 system method could identify 15 (62.5%) strains as Vibrio species and 7 (29.2%) strains as non-Vibrio species, but could not identify the rest 2 (8.3%) strains. But species-specific PCR method could identify 16 (66.7%) strains as Vibrio species and could not identify the rest 8 (33.3%) strains. Among the 24 Vibrio shrimp strains, these two methods could unanimously identify 7 (7/24, 29.2%) strains (2 V. parahaemolyticus, 4 V. alginolyticus, and 1 V. mimicus). Considering that such different identification results were obtained using the two different methods in this study, identification method for Vibrio species must be carefully chosen.

• Microbiology and Biotechnology Letters
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• 제29권2호
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• pp.78-83
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• 2001

Phytase (myo-inositol hexakisphosphate phosphohydrolase: EC 3.1.3.8) hydrolyzes phytic acid (myo-inositol hexakisphosphate) to myo-inositol and monophosphates. In order to obtain phytase producing bacteria, many samples were collected from various soils. Among thirty-five phytase-producing strains, YH100 showed the highest phytase activity. In order to identify the selected YHlOO strain, the morphological and physiological characteristics were examined according to the method of Bergey's manual by 168 rRNA sequence, cellular fatty acids profile, O+C contents and physiological test using API 20E kit. The strain YH100 identified to be a genus of Enterobacter cloacae and was named as Enterobacter cloacae YHlOO. Optimum medium for the phytase production by the Entemhacter c!o([we YHlOO was composed of 2.0%(w/v) glucose, 1.0%(w/v) peptone, 1.0%(w/v) beef extract, 0.1 %(w/v) KCI. and 0.1 %( w/v) sodium phytate.