• Journal of Life Science
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• v.28 no.3
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• pp.361-368
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• 2018

This study investigated the diversity of communities of intestinal microorganisms, separated from the intestinal organs of Red tilefish (Branchiostegus japonicas), collected on the Jeju Coast. First, in the isolation of 1.5% BHIA, MA, TSA and R2A Agar on the medium, there were most colonies in 1.5% BHIA. The results of aerobic culture and anaerobic culture were $1.7{\times}10^6CFU/g^{-1}$ and $1.1{\times}10^5cfu/g^{-1}$, respectively, on average, and 147 pure colonies were separated in total. In 16S rDNA sequencing, there were 58 genera and 74 species, showing 95-100% similarity with the basic strain. They were divided broadly into 5 phyla, and as the main phyletic group, Proteobacteria phylum comprised 50% with 9 families, 35 genera and 35 species of Moraxellaceae, Rhodobacteraceae, Shewanellae, Halomondaceae, Enterobacteriaceae, Vibrionaceae, Hahellaceae, Pseudomonadaceae, and Erythrobacteraceae, with the highest index of dominance. Actinobacteria phylum comprised 24% with 8 families, 11 genera and 17 species of Microbacteriaceae, Intrasporangiaceae, Dietziaceae, Dermabacteraceae, Dermacoccaceae, Nocardiodaceae, Brevibacteriaceae and Propionobacteriacea; Firmicutes phylum, 16% with 6 families, 8 genera and 17 species of Bacillaceae, Staphylcoccaceae, Planococcaceae, Streptococcaceae, Paenibacillaceae and Clostridiaceae; Bacteroidetes phylum, 6% with 2 families, 3 genera and 4 species of Cyclobacteriaceae and Flavobacteriaceae; and Deinococcus-Thermus phylum, 4% with 1 family, 1 genus and 1 species of Deinococcaceae.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.141-148
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• 1988

Though the cultivation history of soybean in Korea is relatively long, taxonomical study on symbiont nodule bacteria, Rhizobium japonicum is not carried out yet systematically. This work was for the taxonomical study on Korean native R. japonicum by recognizing isolates seroimmunologically as well as for the elucidation of its affinity with host soybean variety. Twenty seven isolates from 13 soybean cultivars cultivated at Seoul National University's experiment field and 6 strains of R. japonicum preserved in our laboratory have been tested. Tube agglutination test, agglutinin adsorption test, and gel immune diffusion test were used. The results obtained are as follows: 1. Twenty five isolates and strains of R. japonicum among 33 were classified into 4 serogroups and identified as indivisual serotype. 2. Two isolates isolated from Hill and Milyang cultivars, 2 isolates from Bangsa and Jangbaek, and 4 isolates from Paldal, Sae-al, and Jangbaek were identified as the same serotype respectively. 3. Seroimmunological tests may be adapted for the elucidation of the affinities between the strains and soybean cultivars as well as strain recognition and systematic classification of Korean native R. japonicum.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.125-132
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• 2009

In order to develop probiotics which may be a viable alternative of antibiotic use in pig industry, five bacterial strains (Lactobacillus sp. HN 52, 92, 98, 235 and AP 116) possessing antimicrobial properties were selected from 500 strains isolates of pig intestines. The bacteriocin produced by Lactobacillus sp. HN 235 displayed a relative broad spectrum of inhibitory activity against all Enterococcus strains, Pseudomonas aeruginosa, Listeria monocytogenes and Clostridium perfringens using the spot-on-lawn method. The production of antimicrobial substance started in the middle of the exponential growth phase, reached maximum levels (6,400 AU/mL) in the stationary phase, and then declined. Bacteriocin activity remained unchanged after 30 min of heat treatment at $95^{\circ}C$ and stable from pH 2.0 to 10 for 1 h, or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.182-188
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• 2008

A hyperthermophilic bacteria (strain HJ6) was isolated from a hot springs located in the Arima-cho, Hyogo, Japan. The cells were long-rod type ($2-4{\mu}m$), about $0.4{\mu}m$ in diameter. The pH and temperature for optimal growth were 6.5 and $80^{\circ}C$, respectively. Phylogenetic analysis based on the 16S rDNA sequence and biochemical studies indicated that HJ6 belonged to the genus Thermus thermophilus (Tt). The gene encoding the Trehalose synthase (TS) was cloned and sequenced. The open reading frame (ORF) of the TtTS gene was composed of 2,898 nucleotides and encoded a protein (975 amino acids) with a predicted molecular weight of 110.56 kDa. The deduced amino acid sequence of TtTS showed 99% and 83% identities to the Thermus caldophilus TS and Meiothermus ruber TS, respectively. TtTS gene was expressed in Escherichia coli cells, and the recombinant protein was purified to homogeneity. The optimal temperature and pH for Trehalose synthase activity were found to be $80^{\circ}C$ and 7.5, respectively. The half-life of heat inactivation was about 40 min at $90^{\circ}C$. The maximum trehalose conversion rate of maltose into trehalose by the enzyme increased as the substrate concentration increased, and reached 55.7% at the maltose concentration of 500 mM, implying that the enzyme conversion was dependent of the substrate concentration.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.360-366
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• 1995

1-$\beta$-Methyl carbapenem-2-substituted pyrroudine derivatives. CRB 529 and CRB 550, were synthesized as investigational carbapenem derivatives. It has been reported that the in vitro antibacterial activities of the compounds against G(+) and G(-) bacteria were almost the same or more effective than those of imipenem (IPM) and meropenem (MEPM), and also showed better in vivo efficacy than MEPM and inlipeneni/cilastatin (IPM/CS) against representative G(-) organisms, P. aeruginosa and MRSA organisms, S. aureus. The antibacterial activities, pharmacokinetics and protective efficacy of IPM/CS and CRB 529 and CRB 550 wereconducted after subcutaneous or intravenous administration to mice and rats. The pharmacokinetic parameters of CRB 529 and CRB 550 in mice were as follows: the observed maximal serum concentrations (C$_{max}$) following I.V. administration were 87.5 and 101 $\mu\textrm{g}$/ml for CRB 529 and CRB 550, respectively, and 63.6 $\mu\textrm{g}$/ml for IPM/CS. The half-lives (t$_{1/2}$) were 14.0 and 12.0 n-dn for CRB 529 and CRB 550, respectively, and 14.8 min for IPM/CS. In rats, $C_{max}$ after I.V. administration were 74.0 and 91.8 $\mu\textrm{g}$/ml for CRB 529 and CRB 550, respectively, and 41.2 $\mu\textrm{g}$/ml for IPM/CS. The tissue levels of CRB 529 and CRB 550 and IPM/CS after I.V. administration at a dose of 20 mg/kg decreased by the following order: lung, heart, kindney, liver and spleen for CRB 529, lddney, liver. lung, heart and spleen for CRB 550 and kidney, lung, liver, heart, spleen and brain for IPM/CS. In systemic infection, CRB 529 and CRB 550 showed excellent efficacies against P. aeruginosa and S. aureus (MRSA) at a dose of 5 mg/kg. The PD$_{50s}$ were 0.80, 0.36 mg/kg for CRB 529 and CRB 550, respectively, and 3.22 mg/kg for IPM/CS against P. aeruginosa. The corresponding values against S. aureus (MRSA) were 76.0, 55.3 mg/kg for CRB 529 and CRB 550, respectively, and 146 mg/kg for IPM/CS. In local infection, the antibacterial activities of CRB 529 and CRB 550 were more effective than those of IPM/CS against intrarenal infection with E. coli and P. aeruginosa and also showed as effective as IPM/CS against respiratory tract infection with E. coli and P. aeruginosa at a dose of 5 mg/kg.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.327-333
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• 2005

Dihydroxy-acid dehydratase (DHAD, 2,3-dihydroxy-acid hydrolyase, EC 4.2.1.9) is one of the key enzymes involved in the biosynthetic pathway of the branched chain amino acid isoleucine and valine. Although the enzyme have been purified and characterized in various mesophiles including bacteria and eukarya, the biochemical properties of DHAD has bee not yet reported from hyperthermophilic archaea. In this study, we cloned, expressed, and purified a DHAD homologue from the thermoacidophilic archaeon Sulfolobus solfataricus P2, which grows optimally at $80\;^{\circ}C$ and pH 3, in E. coli. Characterization of the recombinant S. solfataricus DHAD (rSso_DHAD) revealed that it is the dimeric protein with a subunit molecular weight of 64,000 Da in native structure. rDHAD showed the highest activity toward 2,3-dihydroxyisovaleric acid among 17 aldonic acid substrates Interestingly, this enzyme also displayed 50 % activities toward some pentonic acids and hexonic acids when compared with the activity of this enzyme to the natural substrate. Moreover, rSso_DHAD indicated relatively higher activity toward D-gluconate than any other hexonic acids tested in substrates. $K_m$ and $V_{max}$ values of rSso_DHAD were calculated as $0.54\;{\pm}\;0.04\;mM$ toward 2,3dihydroxyisovalerate and $2.42\;{\pm}\;0.19\;mM$ toward D-gluconate, and as $21.6\;{\pm}\;0.4\;U/mg$ toward 2,3-dihydroxyisovalerate and $13.8\;{\pm}\;0.4\;U/mg$ toward D-gluconate, respectively. In the study for biochemical properties, the enzyme shows maximal activity between $70^{\circ}C$ and $80^{\circ}C$, and the pH range of pH 7.5 to 8.5. The half life time at $80^{\circ}C$ was 30 min. A divalent metal ion, $Mn^{2+}$, was only powerful activators, whereas other metal ions made the enzyme activity reduced. $Hg^{2+}$, organic mercury, and EDTA also strongly inhibited enzyme activities. Particularly, the rSso_DHAD activity was very stable under aerobic condition although the counterparts reported from mesophiles had been deactivated by oxygen.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.221-226
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• 2001

Various sterilization methods were applied to the powder of ginseng for the improving hygienic quality. Ultra-violet (UV) and Infrared ray (IR) treatments could not inhibit highly growth of bacteria in ginseng powder. However, high hydrostatic pressure treatment showed high inhibition rate against bacterial growth in ginseng powder. Changes of viable cell count by the pressure showed positive relationship between growth inhibition rates and the pressures applied. When powder was treated with 2,000 kg/$\textrm{cm}^2$ for 10 min at $25^{\circ}C$, initial viable cell count of the powder, 2.0$\times$10$^4$CFU/g, was decreased to 1.0$\times$10$^4$CFU/g. When it treated with 3,000, 4,000 and 5,000 kg/$\textrm{cm}^2$ of pressures under the same condition, viable cell counts were 8.0$\times$10$^3$, 7.0$\times$10$^3$and 1.8$\times$ 10$^3$CFU/g, respectively. Ginseng saponins of the powders were all detected when analyzed by TLC chromatography after treatment with the Pressures. Therefore, it was considered that saponin of ginseng powder was stable under the condition of 5,000 kg/$\textrm{cm}^2$ of pressure, even though the treatment induced coagulation of the powder.

• Journal of Life Science
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• v.18 no.2
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• pp.255-263
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• 2008

Bacteria that antagonize plant pathogenic fungi were isolated from the sediment soil at the Ansan industrial estate. One isolate of them showed growth inhibition of Rhizoctonia solani, Botrytis cenerea, and Fusarium oxysporum. This strain was identified as Pandoraea sp. based on phenotypic and phylogenetic characteristics and termed Pandoraea sp. BCNU 315. Tryptone as nitrogen source and sucrose as carbon source were found to be most effective for the microbial growth. In addition, the optimum temperature and pH for microbial growth were $30^{\circ}C$ and pH 7.0, respectively. The substances generated from Pandoraea sp. BCNU 315 were purified and analyzed by column chromatography, HPLC, GC-MS and NMR. As a result, one compound was determined to be indole, another compound was predicted as cyclopentadecaheptene. Detailed structural clarification of the all of the rest six compounds from Pandoraea sp. BCNU 315 has to be accompanied in the further studies.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.85-88
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• 1997

In orther to isolate antibacterial substances from the flower of Chrysanthemum zawadskii Herbich var. latilobum Kitam., the chloroform fraction was fractionated according to the activity against B. subtilis, S. aureus and V. parahaemolyticus. Two antibacterial substances were isolated and purified by preparative TLC and recrystallization. Compound I showed activity against all the tested bacteria and compound II exhibited the activity against B. subtilis and v. parahaemolyticus except S. aureus. Compared to benzoic acid and sorbic acid which are being used as food preservatives, compounds I and II showed about five-fold stronger antibacterial activity against B. subtilis and V. parahaemolyticus. On the basis of spectrometric studies including $^1H-NMR,\;^{13}C-NMR,\;DEPT,\;^1H-^1H\;COSY,\;^{13}C-^1H\;COSY$ and Mass, compounds I and II were identified as angeloylcumambrin B and cumambrin A, respectively. This is the first report of the isolation of angeloylcumambrin B and cumambrin A from this plant.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.262-267
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• 2007

To access the natural product antibiotics produced by uncultured microorganisms, six cosmid libraries of DNA extracted directly from soil samples (environmental DNA, eDNA) were constructed and screened for the production of antibacterial active molecules. Of the approximately 60,000 clones screened, one antibacterial clone (YS92B) was detected. Ethyl acetate extracts of clone YS92B showed antibacterial activity against various pathogenic bacteria (Listeria monocytogenes, Bacillus subtilis, Pseudomonas syringae, Xanthomonas campestris pv. oryzae, Staphylococcus epidemis). Active constituents from cultures of YS92B were isolated and purified using a bioassay-guided fractionation against B. subtilis through a series of procedures (ethyl acetate extraction, Sephadex LH20 column chromatography, High Performance Liquid Chromatography). NMR (Nuclear Magnetic Resonance) spectral analysis of a major antibacterial active YS92B-VII indicated that it is a lauric acid linked to tyrosine. This report describes the characterization of antibacterially active long chain N-acyl derivatives of tyrosine that are produced by eDNA clones hosted in Escherichia coli from Korean soils.