• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.189-194
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• 2003

Contamination of bacterial infection is one of serious problems in in vitro culture system of root crops. From the contaminated tubes over 140 of petiole cultures of Pinellia ternata, a medicinal plant, 4 genera 8species 48 strains of bacteria, including Aeromonas and Pseudomonas, were isolated and identified and another 8 strains were not fully identified. Most of them were motile Gram positive bacteria as in common in early stage of in vitro cultures. Six strains of bacteria, 5 of Gram negative, including Enterobacter, and 1 of Gram positive, were identified from the embryonic axes cultures of tea plant. From the susceptibility test to pre-screened 5 antibiotics, all of the bacteria except for 2 species of Pseudomonas were susceptible to cefotaxime 60∼100mg/L. While 60mg/L erythromycin only was effective to Pseudomonas. Combination of erythromycin 20mg/L and cefotaxime 60mg/L totally suppressed the growth of all bacterial strains tested. Susceptibility test of bacteria from tea embryonic axes cultures showed similar results. Combination of erythromycin 35mg/L and cefotaxime 60mg/L was effective to 15 bacterial strains and partially effective to 1 unidentified.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.304-308
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• 2012

In vitro antibacterial activity of DW286 was tested against recently collected clinical isolates of Gram-positive strains by the two fold agar dilution method. In vivo activity of DW286 was also determined against systemic infections in mice caused by Staphylococcus aureus. DW286 showed 16~64-fold more potent in vitro activities than ciprofloxacin against Gram-positive bacteria. Against systemic infection model caused by two S. aureus strains, one being methicillin-susceptible and the other methicillin-resistant, DW286 ($ED_{50}s$, 0.16 mg/kg and 4.36 mg/kg, respectively) was more potent than gemifloxacin (1.37 mg/kg, 26.58 mg/kg, respectively).

• YAKHAK HOEJI
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• v.21 no.4
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• pp.211-213
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• 1977

Since ampicillin, one of the important semi-synthetic derivatives of penicillins, is restricted in use because of its unfavorable physico-chemical and pharmacological properties, the author synthesized a new derivative, methampicillin lysinate and its physical and characteristics were determined. The antibacterial activity of this compound against ten species of Gram positive and negative bacteria in vitro showed that it was more active to Gram negative bactria than the positive and that was three times more potent than ampicillin trihydrate.

• The Korean Journal of Mycology
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• v.23 no.1 s.72
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• pp.28-36
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• 1995

To investigate the antibacterial activities of 53 species of mushrooms for Gram-positive bacteria, bioactive substances from mushrooms were extracted with petroleum ether, 80% ethanol, and distilled water. The 14 extracts of 12 species of mushrooms, largely with 80% ethanol, showed antibacterial activities against 6 species of Gram-positive bacteria selectively. Especially, the extracts of Thylopilus PS-5, Pulveroboletus PS-7, and Russula PS-9 showed various antibacterial activities against several bacteria. Minimal inhibitory concentration (MIC) of the 80% ethanol extracts from Pulveroboletus PS-7 and Boletus PS-8 was $300\;{\mu}g/ml$ against Bacillus subtilis, and that of the 80% ethanol extracts from Trichaptium PS-3 was $500\;{\mu}g/ml$ against Micrococcus luteus. MIC of other extracts with antibacterial activities was above $1000\;{\mu}g/ml$.

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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• pp.107-114
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• 2015

Endophytes provide multifarious benefits such as promotion of plant growth and yield, suppression of phyto-pathogens, phosphate solubilising and fixation nitrogen. A study has been carried out to explore growth promotion and antifungal activities of endophytes of mulberry (Morus spp.). Endophytic bacteria were isolated from mulberry plants and studied their cultural, morphological characters, growth promotion as well as their antifungal activity against Rhizoctonia bataticola and Fusarium oxysporum , two mulberry root rot associated pathogens. Except two isolates, all bacteria were colourless and the colony size of eight isolates was small. The margin of five isolates was irregular and the consistency of three isolates was creamy, six isolates was slimy and one was mucoid. Texture of seven isolates was convex and others were flat. Eight isolates were gram positive and the rest Gram negative, five were cocci and others were bacilli (rod shaped). Four isolates were motile and all were catalase positive and only three isolates were oxidase positive. Spore staining was positive only for two isolates. The growth promotion study showed that there was significant difference in root length and seedling length. The antagonistic effect of the bacterial isolates was tested against R. bataticola showed significant (p <0.05) influence of the bacteria, days after inoculation and their interaction on the inhibition of fungal growth. The isolate En-7 completely inhibited the fungus followed by En-5 (66.67%). The bacterial isolates significantly (p <0.05) inhibited growth of F. oxysporum in PDA. The mean inhibition was higher (70.45%) in case of En-7 followed by En-8 (68.65%) and En-10 (66.44%). The study reveals that some endophytic bacteria associated with mulberry have growth promotion and antifungal activity and could be explored for promotion of mulberry growth and managing root rot disease.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.693-699
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• 2001

An intracellular levansucrase gene, lscR from Rahnella aquatilis ATCC 15552, was cloned and its nucleotide sequence was determined. Nucleotide sequence analysis of this gene revealed a 1,238 bp open reading frame coding for a protein of 415 amino acids. The levansucrase was expressed by using a T7 promoter in Escherichia coli BL21 (DE3) and the enzyme activity was detected in the cytoplasmic fraction. The optimum pH and temperature of this enzyme for levan formation was pH 6 and $30^{\circ}C$, respectively. The deduced amino acid sequence of the lscR gene showed a high sequence similarity (59-89%) with Gram-negative levansucrses, while the level of similarity with Gram-positive enzymes was less than 42%. Multiple alignments of levansucrase sequences reported from Gram-negative and Gram-positive bacteria revealed seven conserved regions. A comparison of the catalytic properties and deduced amino acid sequence of lscR with those of other bacterial levansucrases strongly suggest that Gram-negative and Gram-positive levansucrases have an overall different structure, but they have a similar structure at the active site.

• Food Engineering Progress
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• v.13 no.4
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• pp.352-359
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• 2009

Lactic acid bacteria was isolated for the production of probiotic animal feed supplemented with garlic and its antimicrobial properties were investigated. A total of 112 strains of lactic acid bacteria which grew on the medium containing garlic extract were isolated from kimchi, jeotgal, and jangachi. Among them 14 strains were tested for acidand bile salt-resistance as well as antimicrobial activities against animal pathogenic bacteria such as Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, and Shigella flexneri. Of these strains, a strain P'GW50-2 from pickled scallion with most desirable properties was selected and identified as Lactobacillus plantarum TJ-LP-002. Antimicrobial activity of L. plantarum TJ-LP-002 showed relatively wide range of inhibition spectrum against Gram negative bacteria such as Aeromicrobium hydrophila, E. coli, Pseudomonas, Salmonella, Shigella, and some Gram positive bacteria such as Bacillus cereus, Staphylococcus aureus, Clostridium perfringens, and Propionibacterium.

• Korean Journal of Veterinary Service
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• v.44 no.3
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• pp.169-174
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• 2021

Mastitis is an inflammatory condition of the mammary gland, most often caused by bacterial infections, resulting in significant economic losses to the dairy industry. Antimicrobial resistance has been of great concern because of the extensive clinical use of antibiotics. For this reason, the development of new compounds as an alternative treatment to bovine mastitis is needed. Bee venom has been widely used as an oriental treatment for several inflammatory diseases and bacterial infections. The aim of the present study was to evaluate the antimicrobial activity of bee venom on bacteria isolated from bovine mastitis. A total of 107 isolates from bovine mastitic milk samples collected in 2019 and 2020 in Jeonbuk province. All bacterial isolates were tested for susceptibility to bee venom of the honey bee (Apis mellifera). In order to obtain comprehensive antibacterial activities of the bee venom, we measured the minimal inhibitory concentration (MIC) of the bee venom against bacterial strains. Bee venom showed significant inhibition of bacterial growth of Gram-negative bacteria Citrobacter spp., Escherchia coli, Klebsiella spp., Pseudomonas spp., Serratia spp. and Raoultella with MIC values of 96, 81, 72, 230, and 85 ㎍/mL, respectively, and Gram-positive bacterial Enterococcus spp., Staphylococcus spp. and Streptococcus spp. with MIC values of 29, 21 and 16 ㎍/mL, respectively. The results indicated that the MIC values were different depending on the bacterial strains, and those of Gram-positive bacteria were lower than those of Gram-negative bacteria for bee venom. These findings suggested that bee venom could be an effective antimicrobial treatment for bovine mastitis; however, further research is necessary to evaluate the mechanism underlying the antimicrobial action, its effectiveness/safety in vivo and effective application for therapeutic use.

• Journal of Korean society of Dental Hygiene
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• v.7 no.2
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• pp.189-196
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• 2007

A study of the J health college dept of dental hygiene practice vistant a total of 35 supragingival calculus and subgingival calculus picking SEM observation and bacteria identification of the result are followings. 1. As observed by dental calculus SEM, the surface roughness appeared as peaks, valleys, and pits. 2. About bacteteria morphology blood agar plate small green zone partial hemolysis colony streptococcus observation 3. Isolated colony gram stain gram are positive display 4. Supragingival calculus at Lactococcus lactis spp. Leuconostoc spp. Streptococcus mitis, Aerococcus viridans bacteria 1, 3, 3, 16 species detection 5. Subgingival calculus at Aerococcus viridans, Leuconostoc spp. bacteria 5, 1 species detection.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.158-162
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• 2006

Cyclic dipeptides isolated from Streptomyces sp. have been shown to have antimicrobial activity as well as other potentially useful biological activities. The purpose of this study was to compare the in vitro activity of two cyclic dipeptides combined against anaerobic bacteria with the activity of other antimicrobial agents. Specifically, the in vitro activity of the combination of two cyclic dipeptides was investigated against 140 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of erythromycin, cefoxitin, imipenem, clindamycin, and metronidazole. The cyclic dipeptide combination and imipenem were the most active antimicrobial agents tested. In addition, the cyclic dipeptide combination had a radioprotective effect on five normal human lung fibroblast cells, showing survival rates higher $(>90\%)$ than either of the two cyclic dipeptides alone $(<80\%)$.