• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.832-836
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• 2000

A bactirium prohibiting the growth of fungus Botrytis cineria KT 433 was isolate and identified from soil. The isolated strain was gram positive, aerobic bacteria with cream color, round and mucoid. It showed ord form of 0.45$\times$1.1 ${\mu}{\textrm}{m}$ at the cultivated for 24 hrs and the ellipsoided endospore wer observed after culting for 72 hrs. The optimum growth temperature and pH wer 35$^{\circ}C$ and pH 5.0~8.0, respectively. It could assimilate daxtrin, maltose, glucose, mannose, ribose and collobiose as a sole carbon source. The isolated was confirmed to be a Bacillus sp. strain from the findings. The antibiotic from the isolated strain was stable up to 121$^{\circ}C$. The strain, especially, showed specific activity for mold and yeast. However, there was not significant antibacterial activity.

• Journal of Medicine and Life Science
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• v.20 no.1
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• pp.43-47
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• 2023

Streptococcus suis (S. suis) is an emerging zoonotic pathogen that causes bacterial meningitis in humans. S. suis is an encapsulated gram-positive facultative anaerobic bacterium and is an important pathogen in pigs. This infectious disease usually manifests in humans as meningitis, endocarditis, septicemia, and arthritis. Most cases originate in Southeast Asia, and human S. suis infections are often reported in countries with a high density of pigs. Meningitis is a common clinical manifestation of S. suis infection. Moreover, hearing loss is a common complication that can be bilateral, profound, and/or permanent. This report presents two cases of bacterial meningitis and hearing loss caused by S. suis in patients without a history of direct exposure to pigs in an intensive pork industry region.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.74-80
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• 2005

For the reseach of the natural marine antioxidant, an antioxidant-producing bacterium was isolated from seawater in Jeju costal area. The isolated strain SC2-1 was Gram-positive, catalase positive, oxidase negative, motile and small rods. The strain utilized sucrose, dextrose, fructose, mannitol and maltose as a sole carbon and energy source and NaCl required for growth. The radical scavenging activity of the culture supernatant was detemined by DPPH method. This bacterium was identified based on morphological, biochemical characteristics and 16S rDNA sequence analysis, and then was named Exiguobacterium sp. SC2-1. The optimum conditions of culture for production antioxidnat were $25^{\circ}C$, pH 6-8 and $4\%$ NaCl. The stain showed the highest activity and growth cultured in medium which added $1\%$ maltose. Hydroxyl radical activity of the supernatant of Exiguobacterium sp. SC2-1 was $73\%$. The SOD activity of the culture supernatant was estimated about $35\%$.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.88.1-88.13
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• 2020

Background: Listeria monocytogenes is a gram-positive bacterium that causes listeriosis mainly in immunocompromised hosts. It can also cause foodborne outbreaks and has the ability to adapt to various environments. Peptide uptake in gram-positive bacteria is enabled by oligopeptide permeases (Opp) in a process that depends on ATP hydrolysis by OppD and F. Previously a putative protein Lmo2193 was predicted to be OppD, but little is known about the role of OppD in major processes of L. monocytogenes, such as growth, virulence, and biofilm formation. Objectives: To determine whether the virulence traits of L. monocytogenes are related to OppD. Methods: In this study, Lmo2193 gene deletion and complementation strains of L. monocytogenes were generated and compared with a wild-type strain for the following: adhesiveness, invasion ability, intracellular survival, proliferation, 50% lethal dose (LD₅₀) to mice, and the amount bacteria in the mouse liver, spleen, and brain. Results: The results showed that virulence of the deletion strain was 1.34 and 0.5 orders of magnitude higher than that of the wild-type and complementation strains, respectively. The function of Lmo2193 was predicted and verified as OppD from the ATPase superfamily. Deletion of lmo2193 affected the normal growth of L. monocytogenes, reduced its virulence in cells and mice, and affected its ability to form biofilms. Conclusions: Deletion of the oligopeptide transporter Lmo2193 decreases the virulence of L. monocytogenes. These effects may be related to OppD's function, which provides a new perspective on the regulation of oligopeptide transporters in L. monocytogenes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.875-885
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• 2022

This study was performed to confirm the optimal extraction method for antimicrobial peptides from the Hard-shelled mussel. Extractions were performed with two processes including 1% HAc/boiling and 1% HAc/non-boiling methods and used extracts for the comparison of the antimicrobial activity, protease stability, action mechanism, AU-PAGE (acid-urea PAGE), and HPLC chromatograms. 1% HAc/boiling extract showed potent antibacterial activities both against Gram-positive and negative bacterium but 1% HAc/non-boiling extract showed antibacterial activity only against Gram-positive bacteria. Treatment of 1% HAc/boiling extract with proteases retained almost antibacterial activity against B. subtilis, but abolished significant antibacterial activity against E. coli D31. Only 1% HAc/boiling extract showed two discrete clearing antibacterial zones including slow migrating and rapid migrating zones. Both extracts showed strong DNA-binding ability but did not show bacterial membrane permeabilizing ability. In comparison of the chromatogram obtained from C₁₈ or cation-exchange HPLC, the eluted peaks from 1% HAc/boiling extract showed high hydrophobic property or absorbance compared to 1% HAc/non-boiling extract, respectively. The concentration of the purified antimicrobial peptide was also higher in 1% HAc/boiling extract than in 1% HAc/non-boiling extract. Our results suggest that the effective extraction condition for antimicrobial peptides from marine invertebrate is boiling process in a weak acetic acid solution (1%).

• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.163-168
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• 1980

The antibiotic bacterium JS7901, one of the eighty three antibiotic microorganisms which have been is elated in the surburbs of CheongJu-city, showed the most effective antimicrobial activities against test organisms, both bacteria and fungi. Among the different culture media Soytone Sugar medium was the most effective for growth and activity of the JS7901 antibiotic bacterium a against both Escherichia coli and Staphyllococcus aureus by the cylinder plate method. The higher the sugar content, was, the greater the antibiotic amount of substances of JS7901 were produced in the soytone sugar media. The antibiotic bacterium, JS7901 appeared to have a broad activity spectrum showing inhibition in Vitro against gram positive and negative bacteria and plant disease fungi. In general, the active substances were not transferred into organic solvents. Only a small portion of the activity was transferred into ethyl ether and was also adsorbed to active carbon when the cultured broth was also adsorbed to active carbon when the cultured broth was at $pH\;2.0\~4.0$. On adjusting at pH 8.0, the activity disappeared. The crude active substances could be obtained by means of vacuum drying method and still shelved strong activity. The dried active rake was solved by solvents and crystallized into various shapes. The active substances were developed on the silica gel plate in the solvent system of n-butanol-acetic acid-water(3 : 1 : 1) and gave 5 pinkish colored spots when sprayed with $0.2\%$ ninhydrine in ethanol. The upper 5th spot, which was the result of using disc plate method with Escherichia coli was the strongest of these spots.

• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.99-109
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• 2007

Cellulomanas sp. CS 1-1 was studied for its morphological, physiological and biochemical characteristics, together with DNA homology and fatty acid pattern to elucidate its taxonomical position in the species level. Colony morphology of CS1-1 exhibited circular form, opaque, convex, entire edge and pale yellow. Cells were of rod with the size of $0.3{\sim}0.5{\times}0.8{\sim}1.2{\mu}m$, while coryneforms were formed at the early stage of culture. D-ribose, raffinose, rhamnose, acetate, propionate, L-lactate, D-gluconate, aspartate and proline were not utilized as a sole source of carbon, whereas saccharose, arabinose, and amlyose were utilized. Biochemical characteristics of CS1-1 were Gram positive, catalase positive, oxidase negative, nonmotile, facultative anaerobic, mesophilic and G+C content of 74.7 mol %. The major fatty acid and menaquinone were 12-methyltetradecanoic acid(anteiso-$C_{15:1}$) and MK-$9(H_4)$, respectively. These results were correspondent with the characteristics reported for member of the genus Cellulomonas. The strain CS 1-1 exhibited a high level of DNA homology as 70% with C. uda ATCC491, compared to those of 54~59% with C. fimi ATCC 15724, 46~48% with C. biazotea, C. gelida and C. bibula. Finally, strain CS1-1 could be classified as a novel species belongs to C. uda.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.137-142
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• 1998

Helicobacter pylori is a Gram-negative bacterium which causes chronic gastritis and is associated with gastric ulcer, duodenal ulcer and gastric carcinoma. In the process of screening of antibacterial activities against H. pylori from soil microorganisms, fungus No. 60686 was isolated. After fermentation of No.60686, the antibacterial compound was isolated, purified and followed by extraction of mycelium with organic solvents, acetone and ethyl acetate, through silica gel chromatography, LH-20 gel chromatography and HPLC. As a result of the structural analyses of the compound by IR, $^1$H- and $^{13}$C-NMR, FAB/Mass spectrophotometer, the compound having the antimicrobial activity was identified as chaetoglobosin A ($C_{32}H_{36}N_2O_5$), a cytochalasan derivative. The antimicrobial activity of chaetoglobosin A was tested against Gram-positive and negative bacteria by paper disk method. Among the test strains of 9 Gram-positive bacteria and 18 Gram-negative bacteria containing 4 H. pylori strains, the growth of 4 H. pylori strains and 3 S. aureus strains (SG 511, 285 and 503) was only inhibited by chaetoglobosin A. Also it was shown that its growth inhibition against H. pylori strains was stronger than that against S. aureus strains at the treatment of the same concentration. Therefore it was concluded that chaetoglobosin A has a specific growth inhibition against H. pylori of the tested bacteria.

• KSBB Journal
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• v.16 no.5
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• pp.466-473
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• 2001

A bacterium was isolated from soils in Suwon, Korea for the purpose of H$_2$S removal using a biofilter system. The isolate was gram-negative, rod-shaped, catalase-positive, motile, and the isolated bacterium showed a positve in utilizing energy sources including citrate, mannitol, sucrose, fructors, and trehalsoe. Based on its biochemical characteristics it was identified as Burkholderia(Pseudomonas) cepacia. The growth rate of the bacterium in thiosulfate medium with yeast extract was 0.15 hr$\^$-1/ and generation time was 4.6 hr. The cell productivity was 8.05 mg/L$.$h and the isolate grew logarithmically up to 12 hr. The maximum rate of sulfur oxidation was 0.18 g-S/L$.$h. The optimum pH and temperature for the growth of the bacterium were 7.0 and 30$\^{C}$, respectively. The pH range for the growth of B. cepacia was 5.0-8.0. The oxidation rate of thiosulfate was lowered by a substrate thiosulfate when the concentration was higher than 0.12 M. both growth rate and sulfur oxidation rate of Burkholderia(Pseudomonas) cepacia was enhanced about 1.5 times with the addition of 0.2% yeast extract. The removal of hydrogen sulfide was investigated by immobilized B. cepacia with Ca-alginate. The maximum rate removal for H$_2$S was 6.25 g$.$㎤ $.$h$\^$-1/ when 12 L/h of flow rate was supplied. From this study suggest the immobilized B. cepacia could have a potential for H$_2$S removal.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.612-624
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• 2022

A novel Gram-positive, motile, non-spore forming aerobic marine bacterium, designated 107-1^T was isolated from tidal mud collected in Gyehwa-do, South Korea. Cells of strain 107-1^T were short rod or coccoid, oxidase negative, catalase positive and grew at 10-40℃ (with optimum growth at 25-30℃). It utilized menaquinones MK-7 and 8 as its respiratory quinones and its major fatty acids were anteiso-C_15:0 (37.9%), iso-C_16:0 (14.9%), and iso-C_14:0 (10.8%). Phylogenetic analysis based on 16S rRNA gene sequences revealed a distinct clade containing strain 107-1^T and close species Planococcus ruber CW1^T(98.52% sequence similarity), P. faecalis KCTC 33580^T(97.67%), P. kocurii ATCC 43650T(97.48%), P. donghaensis DSM 22276T(97.47%), and P. halocryophilus DSM 24743T(97.37%). Strain 107-1^T contains one circular chromosome (3,513,248bp in length) with G+C content of 44.6 mol%. Estimated ranges for genome to genome distance, average nucleotide identity, and average amino acid identity comparing strain 107-1^T with close taxa were 20.3-34.8%, 77.9-86.9%, and 73.6-92.8%, respectively. Based on polyphasic analysis, strain 107-1^T represents a novel species belonging to the genus Planococcus.