• YAKHAK HOEJI
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• v.10 no.4
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• pp.7-20
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• 1966

1. Of the 32 extracts from Genus of lishenes broth tested for antimicrobial activity, 28 inhibited at least one of the 3 test microorganisms used. 2. Twenty seven lichnes broth from 32 species tested were active against at least one of the Gram-positive bacteria M. pyogenes var, aureus 203 p, and twenty four lichenes broth from 32 Species tested were active against at least one of the Gram-positive bacteria Bacillus subtilis ATCC 6633. 3 Twenty five lichenes broth from 32 species tested were active against at least one of the Gram-negative bacteria Escherichia coli 0.126. 4. The antibiotic substances in lichenes were readily extracted by organic solvents.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.935-941
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• 2003

To investigate the interaction of bacteria and Microcystis isolated from a hypertrophic reservoir(Seo-Nakdong River), the response of five bacteria in relation to the different treatment of Microcystis and microcystin production by addition of dominant bacteria Staphylococcus sciuri were examined. Five bacteria (S. sciuri, S. capitis, S. epidermis, Pseudomonas aeruginosa and Aeromonas aimonicida) were identified from the reservoir. In the experiment of bacterial response, two types of bacterial growth pattern were observed. All bacteria showed active growth in heated Microcystis-added media. Especially, three species of bacteria (S. sciuri, S. capitis and P. aeruginosa) among them showed active growth in live Microcystis-added media. In Microcystis response, increase of microcystin production showed when dominant bacteria, S. sciuri was added.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.1
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• pp.37-40
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• 2012

The apidaecins are highly active against Gram-negative bacteria. Here, we show the expression and antibacterial activity of the bumblebee, Bombus ignitus, apidaecin. We PCR-amplified 51 bp of the active domain sequence of the B. ignitus apidaecin gene and expressed the recombinant B. ignitus apidaecin active domain in baculovirus-infected insect cells. The recombinant B. ignitus apidaecin active domain shows bactericidal activity against Gram-negative bacteria, including Pseudomonas tolaasii, a serious pathogen in cultivated mushrooms, but not Gram-positive bacteria. This result suggests that the active domain of the B. ignitus apidaecin is a potential antibacterial agent for the control of bacterial brown blotch diseases.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1288-1294
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• 2021

There are a growing number of reports of hospital-acquired infections caused by pathogenic bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). Many plant products are now being used as a natural means of exploring antimicrobial agents against different types of human pathogenic bacteria. In this research, we sought to isolate and identify an active molecule from Sedum takesimense that has possible antibacterial activity against various clinical isolates of MRSA. NMR analysis revealed that the structure of the HPLC-purified compound was 1,2,4,6-tetra-O-galloyl-glucose. The minimum inhibitory concentration (MIC) of different extract fractions against numerous pathogenic bacteria was determined, and the actively purified compound has potent antibacterial activity against multidrug-resistant pathogenic bacteria, i.e., MRSA and its clinical isolates. In addition, the combination of the active compound and β-lactam antibiotics (e.g., oxacillin) demonstrated synergistic action against MRSA, with a fractional inhibitory concentration (FIC) index of 0.281. The current research revealed an alternative approach to combating pathogenesis caused by multi-drug resistant bacteria using plant materials. Furthermore, using a combination approach in which the active plant-derived compound is combined with antibiotics has proved to be a successful way of destroying pathogens synergistically.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.110-115
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• 2007

Electrochemically active bacteria were successfully enriched in an electrochemical cell using a positively poised working electrode. The positively poised working electrode (+0.7 V vs. Ag/AgCl) was used as an electron acceptor for enrichment and growth of electrochemically active bacteria. When activated sludge and synthetic wastewater were fed to the electrochemical cell, a gradual increase in amperometric current was observed. After a period of time in which the amperometric current was stabilized (generally 8 days), linear correlations between the amperometric signals from the electrochemical cell and added BOD (biochemical oxygen demand) concentrations were established. Cyclic voltammetry of the enriched electrode also showed prominent electrochemical activity. When the enriched electrodes were examined with electron microscopy and confocal scanning laser microscopy, a biofilm on the enriched electrode surface and bacterium-like particles were observed. These experimental results indicate that the electrochemical system in this study is a useful tool for the enrichment of an electrochemically active bacterial consortium and could be used as a novel microbial biosensor.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.80-84
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• 2001

Vertical and temporal variations of active and total bacterial abundance were monthly estimated in Lake Soyang from April 1999 to January 2000. The number of total and respiring bacteria was determined directly under microscope by AODC and CTC methods, respectively. The number of total and active bacteria varied from $2.1{\times}10^5 to 3.1{\times}10^6 $,$cells{\cdot}ml^{-1}$ and $1.8{\times}10^4 to 8.0{\times}10^5 $,$cells{\cdot}ml^{-1}$, respectively. The proportions of respiring bacteria to total cell ranged from 3.7 to 44.2% : The proportions was the highest in November 1999 and the lowest in December 2000. The specific activity of${\beta}$-glucosidase divided by total bacteria was$1.6{\times}10^5\;amol{\cdot}cell^{-1}{\cdot}hr^{-1}$in August and$1.4{\times}10^5\;amol{\times}cell^{-1}{\times}hr^{-1}$in September while the specific activity divided by CTC active bacteria was about$3.6{\times}10^5\;amol{\cdot}cell^{-1}{\cdot}hr^{-1},\;24.0{\times}10^5\;amol{cdot}cell^{-1}{cdot}hr^{-1}$. The specific activity of active bacteria in September was 6.7 times higher than that of August. By these data of active bacteria, the new information of aquatic ecosystem was unveiled.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.65-71
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• 1995

Bacteriocins from lactic acid bacteria have attracted much attention in recent years because of their useful worth in increasing safety and extending shelf life of foods. These substances show an inhibitory effect against some food spoilage bacteria and food-borne pathogens. The inhibitory effect fo the bacteriocin produces by lactic acid bacteria against Listeria monocytogenes(L. monocytogenes) was examined in this study. The culture supernatants of 5 kinds of bacteria among the 10 kinds of testes lactic acid bacteria had the inhibitory activity against Listeria sp., various Gram positive and Gram negative bacteria. Bacteriocin produced by Lactobacillus plantarum(Lact. plantarum) LMG 7945 was the most active toward L. monocytogenes. Bacteriocin production of the Lact. plantarum LMG 7945 cultured on MRS broth was increased late logarithmic phase over early stationary phase. This bacteriocin was stable at heat treatment and acidic pH relatively; The activity was retained after heating at 121$^{\circ}C$ for 15min and was active in the pH range of 2~4 but was lost above pH 5.

• Journal of Climate Change Research
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• v.5 no.3
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• pp.249-256
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• 2014

Permafrost is frozen soil below $0^{\circ}C$ for two or more years. Surface of permafrost is called as active layer that seasonally thaws during the summer. Although the thawing of permafrost may deepen the active layer and consequently increase the microbial activity, the microbial community structure in this habitat has not yet been well described. In this study, we presented bacterial and archaeal diversity in the active layer soil from Resolute, Canada using pyrosequencing analysis. The soil sample was collected from the surface of the marsh covered with moss and Carex. A total of 7,796 bacterial reads for 40 phyla and 245 archaeal reads for 4 phyla were collected, reflecting the high diversity of bacteria. Predominant bacterial groups were Proteobacteria (37.7%) and Bacteroidetes (30.0%) in this study. Major groups in Archaea were Euryarchaeota (51.4%) and Thaumarchaeota (46.1%). Both methane producing archaea and consuming bacteria were detected in this study. Although it might be difficult to characterize microbial community with only one sample, it could be used for the basis of assessing the relative importance of the specific groups with a high resolution on the bacterial and archaeal community in this habitat.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.27-33
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• 1999

Frost injury of crops is closely related to the epiphytic population dynamics of ice nucleation-active (INA) bacteria, and the injury can be reduced by decreasing the INA bacterial population. In order to predict the epiphytic population of INA bacteria on crops, a rapid and accurate detection method has to be developed. In the previous report, we produced some antibodies against INA proteins purified from the outer membrane of INA bacteria. However it was difficult to produce the antibodies because the purification procedures of the INA proteins were complicated, and the final yield was too low. We designed a specific peptide from the N-terminal region of INA protein by computer analysis and synthesized the peptide in vitro in this experiment. The peptide sequence was Asp-Ser-Por-Leu-Ser-Leu-His-Ala-Asp, that is corresponding to the highly conserved region in several INA proteins, with predicted beta turn, coiling, and hydrophilic region. A polyclonal anti-INA peptide antiserum produced specifically recognized INA bacteria as few as 10 colony-forming units (CFU) in the ELISA reactions and did not respond to other non-INA bacteria. Serological specificity of the anti-INA peptide antiserum will facilitate the forecasting of the INA bacterial population dynamics on crops.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.5-14
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• 2021

It was investigated how the contents of four active ingredients, nodakenin, decursinol, decursin, and decursinol angerate, which are active ingredients of Angelica gigas Nakai, cause material changes depending on the type of bacteria. Fermentation experiments were conducted using 9 types of bacteria: 5 types of Bacillus EMD17, 9-3, HCD2, #8, 191 and 4 types of Lactobacillus KCTC 3320, WCP02, S65, P1201. 1. The contents of decursin and decursinol angerate, which are indicator substances, rapidly decreased after 2 days of fermentation by inoculating Bacillus bacteria in the extract of Angelica gigas Nakai. Even after 4 days of fermentation, the contents of decursin and decursinol angerate were the same as on the 2nd day. On the other hand, the content of nodakenin and decursinol increased after 4 days of fermentation. In addition, the content of decursin increased significantly after 6 days of fermentation. 2. Substance changes of nodakenin and decursinol after inoculation of Bacillus bacteria into the extract of Angelica gigas Nakai were almost non-existent regardless of the type of bacteria. The change in effective content of decursin and decursinol angerate was large in Bacillus EMD17 and 9-3. Changes in the contents of decursin and decursinol angerate were almost non-existent in Bacillus HCD2, #8, and 191 strains. 3. As a result of finding out the change in active ingredient after 8 days of fermentation using 4 types of Lactobacillus KCTC 3320, WCP02, S65, and P1201 extracts of Angelica gigas Nakai, there was almost no change in the contents of nodakenin and decursinol regardless of the type of bacteria. However, in the case of fermentation with Lactobacillus S65 and P1201, the contents of decursin and decursinol angerate were changed.