• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.446-452
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• 2011

Total 480 lactic acid-producing bacteria were isolated from five kinds of kimchi, and their antibacterial activity was tested against Salmonella enterica serovar Typhimurium, Bacillus subtilis, and Pseudomonas aeruginosa using an agar diffusion assay. Among them, 340 isolates showed a halo on MRS agar against one or more indicator strains, which were identified using multiplex PCR, an API 50CHL kit, and a 16S rDNA sequence analysis. As a result, 169 Lactobacillus plantarum, 20 Lactobacillus fermentum, two Lactobacillus paracasei ssp. paracasei, two Lactobacillus sp., and 15 Pediococcus sp. were identified. This may be the first report on the isolation of antibacterial Lactobacillus fermentum from kimchi.

• Journal of Life Science
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• v.11 no.5
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• pp.432-438
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• 2001

Various lactic acid bacteria were isolated from Korean Dongchimi (whole radish Kimichi with added water) in order to study their antimutagenic activity. Ames test using Salmonella enterica serovar typhimurium TA98 and TA100 showed the strain DLAB19 to have the highest antimutagenic activity among the 300 isolated strains against MNNG(N-methyl-N-nitro-N-nitrosoguanidine), NPD (4-nitro-O-phenylenediamine), 4-NQO(4-nitroquinoline-1-oxide) and AFB$_{1}$(aflatoxin B$_{1}$). The strain was identified as Leuconostoc mesenteroides subsp. cremoris according to the Bergeys Mannual Systematic Bscteriology based on its morphological, cultural, physiological characteristics and biological system Antimutagenic activity of Leu. mesenteroides subsp. cremoris DLAB19 was found in the culture supernatant suggesting the bacterium secretes, the antimutagenic substance in the media. The antimutagenic activity of Leu. mesenteroides subsp. cremoris DLAB19 was reconfirmed by the spore-rec assay using spores of Bacillus subtilis H17 (Rec$^{+}$) and M45 (Rec$^{[-10]}$ ).).

• Herbal Formula Science
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• v.27 no.4
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• pp.257-267
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• 2019

Objectives: The purpose of this study was to establish experimental evidence for the antimicrobial effects of 51 herbal formulae commonly used in traditional Korean medical institutions. Methods: The antimicrobial activities of herbal formulae were screened using the disc diffusion method against 10 pathogenic microorganisms (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Vibrio parahaemolyticus, Escherichia coli DH5α, E. coli O157, Salmonella enteritidis, Yersinia enterocolitica, Shigella flexneri, and Helicobacter pylori). Of the 51 herbal formulae, 13 herbal formulae with antimicrobial activity were selected and their dose-dependency were confirmed. Results: Nine herbal formulae, including Gyeji-tang, Dangguisu-san, Saengmaek-san, Samul-tang, Ssanghwa-tang, Socheongryong-tang, Yukmijihwang-tang, Jakyakgamcho-tang, and Paljung-san, presented antibacterial activity against B. cereus. The effects of Saengmaek-san and Paljung-san was sustained for 48 hr. On L. monocytogenes, Dangguisu-san and Hyangsapyeongwi-san showed antimicrobial activity, but only Hyangsapyeongwi-san maintained the activity for 48 hr. Thirteen herbal formulae such as Galgeun-tang, Gyeji-tang, Dangguisu-san, Mahwang-tang, Banhasasim-tang, Saengmaek-san, Socheongryong-tang, Yukmijihwang-tang, Jakyakgamcho-tang, Cheonwangbosim-dan, Palmijihwang-tang, Paljung-san, and Hwanglyeonhaedok-tang showed antimicrobial activity against V. parahaemolyticus, and the activity was maintained for 48 hr. The 51 herbal formulae did not show any antimicrobial activity against seven strains such as E. coli DH5α, E. coli O157, S. aureus, S. enteritidis, Y. enterocolitica, S. flexneri, and H. pylori. Conclusions: Nine, two, and thirteen herbal formulae showed antimicrobial activities against B. cereus, L. monocytogenes, and V. parahaemolyticus in a dose-dependent manner, respectively. The results of antimicrobial activity of 51 herbal formulae against 10 microorganisms might be used as the basis for new application of herbal formulae.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.39-44
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• 2014

Glass discs functionalized with alkynyl (GDA) terminated monolayers were prepared and incubated in $AgNO_3$ solution (GDA-Ag). The modified functional glass surfaces were characterized by X-ray photoelectron microscopy (XPS). The potential of GDA and GDA-Ag as antimicrobial surfaces was investigated. Anti-microbial efficacies of GDA against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Candida albicans was relatively low ranging from 4.67 to 17.00%. However, the GDA-Ag was very effective and its antimicrobial efficacy ranged from 99.90 to 99.99% against the same set of microbial strains except for C. albicans where it was 95.50%. The durability of the Ag bonded to the terminal alkynyl groups was studied by placing the GDA-Ag in PBS buffer solution (pH 7.4) for two weeks. Initially, the silver release was relatively fast, with 40.05 ppb of silver released in first 24 h followed by a very slow and constant release. To study the potential of GDA-Ag for medical applications, in vitro cytotoxicity of GDA-Ag against Human Embryonic Kidney 293 (HEK293) cell lines was studied using WST-assay. The cytotoxicity of the GDA-Ag was very low (5%) and was almost comparable to the control (blank glass disc) indicating that GDA-Ag has a promising potential for medical applications.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.787-790
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• 2016

Kefir is a unique fermented dairy product produced by a mixture of lactic acid bacteria, acetic acid bacteria, and yeast. Here, we compared the antimicrobial spectra of four types of kefirs (A, L, M, and S) fermented for 24, 36, 48, or 72 h against eight food-borne pathogens. Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, and Cronobacter sakazakii were used as test strains, and antibacterial activity was investigated by the spot on lawn method. The spectra, potencies, and onsets of activity varied according to the type of kefir and the fermentation time. The broadest and strongest antimicrobial spectrum was obtained after at least 36-48 h of fermentation for all kefirs, although the traditional fermentation method of kefir is for 18-24 h at $25^{\circ}C$. For kefir A, B. cereus, E. coli, S. Enteritidis, P. aeruginosa, and C. sakazakii were inhibited, while B. cereus, S. aureus, E. coli, S. Enteritidis, P. aeruginosa, and C. sakazakii were inhibited to different extents by kefirs L, M, and S. Remarkably, S. aureus, S. Enteritidis, and C. sakazakii were only inhibited by kefirs L, M, and S, and L. monocytogenes by kefir M after fermentation for specific times, suggesting that the antimicrobial activity is attributable not only to a low pH but also to antimicrobial substances secreted during the fermentation.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.287-293
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• 2011

The purpose of this study was to isolate and characterize fungal deteriogens, which induce discoloration of the cement tunnel, and calcite forming bacteria (CFBs), which have antifungal activity against fungal deteriogens. Isolation of mold, bacteria and yeast was performed using several solid media and partially identified using internal transcribed spacer (ITS); 5.8S rRNA gene sequencing and 16s rDNA sequencing. A total of 19 microbial strains were identified with the most widely distributed fungal strain being Cladospirum sphaerospermum. In addition, five bacteria derived from the tunnel were identified as CFBs. Amongst the latter, Bacillus aryabhatti KNUC205 exhibited antifungal activity against Cladospirum sphaerospermum KNUC253 and Aspergillus niger KCTC6906 as concentrated filtered supernatants.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.987-997
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• 2014

The mature landfill leachate, which is characterized by a high concentration of ammonia nitrogen ($NH_3$-N) and humic acid (HA), poses a challenge to biotreatment methods, due to the constituent toxicity and low biodegradable fraction of the organics. In this study, we applied bioaugmentation technology in landfill leachate degradation by introducing a domesticated $NH_3$-N and HA resistant bacteria strain, which was identified as Bacillus cereus (abbreviated as B. cereus Jlu) and Enterococcus casseliflavus (abbreviated as E. casseliflavus Jlu), respectively. The isolated strains exhibited excellent tolerant ability for $NH_3$-N and HA and they could also greatly improved the COD (chemical oxygen demand), $NH_3$-N and HA removal rate, and efficiency of bioaugmentation degradation of landfill leachate. Only 3 days was required for the domesticated bacteria to remove about 70.0% COD, compared with 9 days' degradation for the undomesticated (autochthonous) bacteria to obtain a similar removal rate. An orthogonal array was then used to further improve the COD and $NH_3$-N removal rate. Under the optimum condition, the COD removal rate in leachate by using E. casseliflavus Jlu and B. cereus Jlu increased to 86.0% and 90.0%, respectively after, 2 days of degradation. The simultaneous removal of $NH_3$-N and HA with more than 50% and 40% removal rate in leachate by employing the sole screened strain was first observed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.605-611
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• 2011

This study examined the suitability of characteristics of potential strains of probiotic bacteria. Among 25 lactic acid bacteria isolated from Korean traditional fermented food, the Hard Clam Meretrix meretrix Shikhae, the SH-10 strain, which exhibited superior resistance to low pH and bile salts, was selected as a potential probiotic bacteria. By examining carbohydrate utilization, morphological properties, and the 16S rRNA gene sequence, the SH-10 strain was identified as Pediococcus pentosaceus (hereafter, P. pentosaceus SH-10). P. pentosaceus SH-10 was resistant to amikacin, cefotetan, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, and vancomycin. Tests of antimicrobial activities against pathogens such as Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis, and Staphylococcus aureus, indicated that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria. These results suggest that P. pentosaceus SH-10 can be developed as a probiotic bacteria.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.87-95
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• 2014

The purpose of this study was to isolate and identify bacteria from the 4 patients with non-odontogenic infectious lesions (mucormycosis, chronic inflammation from wound infection, and two actinomycosis) and determine their antimicrobial susceptibility against eight antibiotics. Bacterial culture was performed under three culture conditions (anaerobic, $CO_2$, and aerobic incubator). The bacterial strains were identified by 16S rRNA gene (16S rDNA) sequence comparison analysis method. For investigating the antimicrobial susceptibility of the bacteria against eight antibiotics, penicillin G, amoxicillin, tetracycline, cefuroxime, erythromycin, clindamycin, vancomycin, and Augmentin$^{(R)}$ (amoxicillin + clavulanic acid), minimum inhibitory concentration (MIC) measurement was performed using broth microdilution assay. Nosocomial pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis, and Neisseria flavescens were isolated from mucormycosis. Veillonella parvula, Enterobacter hormaechei, and Acinetobacter calcoaceticus were isolated from chronic inflammatory lesion. Actinomyces massiliensis was isolated from actinomycosis in parotid gland. Capnocytophaga ochracea was isolated from actinomycosis in buccal region in anaerobic condition. There was no susceptible antibiotic to all bacteria in mucormycosis. Tetracycline was susceptible to all bacteria in chronic inflammation. C. ochracea was resistant to vancomycin and penicillin G; and other antibiotics showed susceptibility to all bacteria in actinomycosis. The results indicated that the combined treatment of two or more antibiotics is better than single antibiotic treatment in mucormycosis, and penicillin is the first recommended antibiotic to treat actinomycosis.

• The Korean Journal of Ecology
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• v.21 no.5_3
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• pp.703-712
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• 1998

Physicochemical factors, microbial population size and the properties of the bacterial isolates were estimated to find out the nature of soil ecosystem of Mt. Nam. Samples were obtained from the surface layer of soils on which specific plant community is developed. Average content of moisture and organic matter of the soils were 21.6% and 17.3%, respectively. These values were similar to those of developing forest soils, but were slightly lower than those of climax ecosystem such as Piagol in Mt. Chiri. Chiri. Content of phosphate was higher than those of other forest soils. The population size of soil bacteria ranged from 27.4 to 195.8 ${\times}\;10^5$ CFU/g. duy soil, and the size is somewhat dependent on the moisture and oranic matter content of soils. A large number of bacteria were able to decompose macromolecules such as starch, elastin and gelatin. Bacterial species composition of each soil was comparatively simple. Pseudomonas, Agrobacterium, Flavobacterium and Xanthomonas which are Gram-negative short rods were widely distributed in the forest soils. The endospore forming Bacillus species were also the main constituents of the soil microflroa. Actinomycetes were widely distributed in the forest soils, but the distribution pattern varied in each site. Most of the actinomycetes were also able to decompose organic macromolecules. The rate of resistant actinomycete strains to antibiotics and heavy metals were lower than those from cultivated soils, but higher than those from well-preserved forest soils. Antibiosis pattern of the actinomycete isolates was similiar to the resistance pattern. This means the forest soils of Mt. nam was somewhat interferred by artificial behabiour.