• Journal of Microbiology and Biotechnology
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• 제8권4호
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• pp.310-317
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• 1998

Peptide synthetases are large multifunctional enzyme complexes that catalyze the nonribosomal synthesis of a structurally diverse family of peptide antibiotics. These enzymes are composed of functionally independent domains with independent enzymatic activities. Their specific linkage order of domains forms the protein template that defines the sequence of the incorporated amino acids. Within each domain, several motifs of highly conserved sequences have been identified from the sequence alignment of the various peptide synthetases ［30］. Taking advantage of the conserved nucleotide sequence of Core 1 and Core 2, we designed PCR primers to amplify the peptide synthetase genes from three different gram-positive bacterial strains. Nucleotide sequence analysis of the amplified PCR products from those three strains showed significant homology to various peptide synthetase genes, suggesting that the PCR products are parts of peptide synthetase genes. Therefore, this rapid and efficient PCR technique can be used for the isolation of peptide synthetase genes from various strains.

• The Plant Pathology Journal
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• 제29권4호
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• pp.446-450
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• 2013

The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produced by the bacterial pathogen Burkholderia glumae. F. graminearum was resistant to toxoflavin, while other fungi were sensitive to this toxin. Supplementing toxoflavin into medium enhanced the isolation of F. graminearum from rice grains by suppressing the growth of saprophytic fungal species. In addition, a medium with or without toxoflavin exposed to wheat fields for 1 h had 84% or 25%, respectively, of colonies identified as F. graminearum. This selection medium provides an efficient tool for isolating F. graminearum, and can be adopted by research groups working on genetics and disease forecasting.

• 한국식물병리학회지
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• 제10권1호
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• pp.13-17
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• 1994

A semiselective agar medium (XCO) was developed for the isolation of bacterial blight pathogen, Xanthomonas campestris pv. oryzae, from rice seed. The medium contained yeast extract 1.0 g, peptone 2.0 g, sucrose 5.0 g, sodium glutamate 1.0 g, FeSO4.7H2O 0.05 g, Fe.EDTA 1 mg, cephalexin 20 mg, Evan blue (0.1%) 1.5 ml, bromcresol purple (0.1%) 2.5ml, cycloheximide 100 mg and agar 15.0 g per liter. Colonies of X. c. pv. oryzae were 4~5 mm in diameter, smooth, round, blue (darker center) and convex after 6 days incubation at 28$^{\circ}C$. The recovery of 6 isolates of X. c. pv. oryzae on the XOC medium ranged from 81% to 120% (mean 98.2%) in comparison to Wakimoto's medium. The number of saprophytic bacteria from 10 rice seed lots on XCO medium was reduced to 70.4% of that on Wakimoto's medium. The recovery of X. c. pv. oryzae added to rice seed on XOC medium ranged from 67% to 87% (mean 75.6%) of that on Wakimoto's medium.

• 대한의생명과학회지
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• 제27권4호
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• pp.310-316
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• 2021

Mobile phones used by healthcare workers are not only an indicator of the contamination of healthcare associated bacteria, but can also be another source of infection. The number and time of handwashing, mobile phone operation time and disinfection were highly relation with the bacterial contamination on the surface of mobile phone. Healthcare associated bacteria isolated from the mobile phone surface were 28 MRCoNS (48.3%), 14 S. aureus (24.2%), 3 MRSA (5.2%), 5 A. baumannii (8.6%), 3 MRAB (5.2%), 3 Entrococcus spp. (5.1%), 2 Pantoea spp. (3.4%), 2 A. lowffii (3.4%), 1 E. cloacae (1.7%), 1 P. stutzeri (1.7%), and P. mirabillis (1.7%). For isolation according to department, 2 MRAB from the emergency room and 1 MRSA from intensive unit, the radiology team and the rehabilitation medical team, respectively were isolated. As a result of the relation of isolates from the department of patient contact (ER, RT, GW, CP, ICU, RMT), the bacterial isolation rate was 75% and the department of patient non-contact (MRT) was 10%.

• 대한미생물학회지
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• 제10권1호
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• pp.19-24
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• 1975

Anaerobic bacteria are the major residents of human skin and mucous membrane. The importance, as opportunistic pathogens, of anaerobic bacteria are well recognized because of more population. with decreased defense against bacterial invasion due to chemotherapy, rediation therapy, extensive surgical operation etc. are dealt at hospitals. An analysis of the anaerobe isolation results at Yonsei University Medical Center during the January 1974-May 1975 period was made and the following results were obtained. 1) From 118 patients 146 strains of anaerobes were isolated. Among these 81.3% were nonsporforming anaerobes. Most frequently isolated anaerobes were Pc. asaccharolyticus, Ps. anaerobius, Ps. intermedius, B. fragilis and Cl. perfringens. 2) Anaerobes were frequently isolated from wound, female genital, intraabdominal, and pleuropulmonary specimens. Fewer anaerobes were isolated from blood, spinal fluid and liver specimens. 3) The ratio of anaerobe isolation to total bacteria isolation were; liver 66.7%, intraabdominal 33.3%, pleuropulmonary 28.9%, spinal fluid 5.0% and blood 4.2%. 4) Among the 118 anaerobe isolated patients, 48.3% yielded anaerobes only and rest of them yielded anaerobes together with aerobes. 5) Most of the gram-positive anaerobes were susceptible to the antibiotics tested. Exception was to tetracycline to which appreciable number showed resistance. It was noteworthy that only 48% of B. fragilis was susceptible to tetracycline.

• Journal of Species Research
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• 제9권4호
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• pp.325-338
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• 2020

The animal gut is filled with highly diverse microbes associated with host metabolism, physiology, and pathology. However, numerous animal gut microbes have not been cultured or reported. We isolated various bacterial species using culture-dependent approaches during a comprehensive investigation of endangered endemic vertebrate species in the Republic of Korea. A total of 18 unrecorded bacterial species were isolated from the feces of an Oriental stork (Ciconia boyciana), and from the intestinal tracts of a cobitid fish (Kichulchoia multifasciata) and a Korean splendid dace (Coreoleuciscus splendidus). Based on a phylogenetic analysis of 16S rRNA gene sequences, we discovered species belonging to the phyla Actinobacteria (eight species), Firmicutes (seven species), Proteobacteria (two species), and Bacteroidetes (one species). Based on their high 16S rRNA gene sequence similarities (>98.7%) and formation of monophyletic clades with type species, each species was classified into an independent and predefined bacterial species. Gram-stain reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and NIBR IDs for each species are described in the species description section.

• Journal of Species Research
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• 제8권4호
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• pp.351-364
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• 2019

Here we describe indigenous prokaryotic species in Korea, a total of 42 bacterial strains affiliated to the class Alphaproteobacteria isolated from various environmental samples: fermented vinegar, sea water, beach sand, fresh water, salt flats, moss, algae, activated sludge, and soil. From the high 16S rRNA gene sequence similarity (>98.7%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to predefined bacterial species. There is no official report that these 42 species included in Alphaproteobacteria in Korea: 15 species of 6 genera in the order Rhodospirillales, 12 species of 10 genera in the order Rhizobiales, 10 species of 8 genera in the order Rhodobacterales, 4 species of 4 genera in the order Sphingomonadales and 1 species of 1 genus in the order Caulobacterales. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.

• Journal of Species Research
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• 제10권1호
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• pp.12-22
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• 2021

During a comprehensive investigation of indigenous prokaryotic species in Korea, 25 and 10 bacterial strains assigned to the classes Alphaproteobacteria and Betaproteobacteria, respectively, were isolated from diverse environmental habitats, including soil, mud, tidal field, sea water, sand, rusted iron, and leaf. Based on their high 16S rRNA gene sequence similarities (>98.7%) and the formation of robust phylogenetic clades with type species, each strain was assigned to an independent and predefined bacterial species. Since there were no published or official reports regarding these 35 isolates in Korea, they - 25 species of 14 families in the 5 orders of Alphaproteobacteria and 10 species of 3 families in the two orders of Betaproteobacteria - have been reported as unrecorded species in Korea. In addition, Gram reaction, 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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• 제11권4호
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• pp.310-320
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• 2022

As a subset study to discover indigenous prokaryotic species in Korea, we isolated 20 bacterial strains and assigned them to the phyla Actinobacteria, Bacteroidota, Firmicutes, and Proteobacteria. From the high 16S rRNA gene sequence similarity (≥98.7%) and formation of a robust phylogenetic clades, we determined that each strain belonged to independent, predefined bacterial species. There are no official reports of these 20 species in Korea; therefore, 7 strains of the Actinobacteria, 2 strain of the Bacteroidota, 3 strains of the Firmicutes, and 8 strains of the Firmicutes are described in Korea for the first time. Gram reaction, colony and cell morphology, basic biochemical characteristics, and isolation sources are also described in the species description section.

• 대한화학회지
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• 제67권2호
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• pp.145-149
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• 2023

Talipariti hamabo is a plant growing around salt marshes in the Lava Coast region of Jeju Island, Korea. In this study, the extract of T. hamabo leaves was investigated for the anti-inflammatory, anti-oxidative and anti-bacterial activities and their active constituents were identified. In the anti-inflammatory tests using lipopolysaccharide-stimulated RAW264.7 cells, the ethyl acetate (EtOAc) fraction inhibited the nitric oxide production without causing cell toxicity. Moreover, the EtOAc fraction reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6) as well as prostaglandin E₂. In the anti-oxidative studies with DPPH and ABTS⁺ radicals, potent scavenging activities were observed in the EtOAc and n-butanol fractions. Upon the anti-bacterial tests using Staphylococcus epidermidis, EtOAc and n-butanol fractions exhibited good activities. Through the phytochemical studies on EtOAc fraction, three components were isolated by repeated column chromatography; oleic acid (1), p-hydroxyphenethyl-trans-ferulate (2), nicotiflorine (3). Based on these results, the extract of T. hamabo leaves can be developed as natural resources for cosmetic applications.