• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.191-195
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• 2002

In previous reports the authors have screened the inhibition effects of marine algae extracts on halitosis, and demonstrated that a brown algae, Eisenia bicyclis (' Daehwang') possess not only strong deodorant effect bug also considerable anticariogenic activities. In this study, we screened antibacterial effects of various marine algae, and measured minimum inhibitory concentration (MIC) value of them against mutans streptococci in vitro. Among the 27 species of marine algae, $80\%$ ethanol extract of dried sea-mustard, Laminaria japonica ('Dasima') showed the strongest inhibition activity against Streptococcus mutans KCTC 3300. The extracts of Ulva lactuca ('Galparae'), Codium fragile ('Cheonggak'), Ecklonia cava ('Gamtae'), E. stolonifera ('Gompi') and Undalia Pinnatifida ('Miyeok') showed slightly weaker inhibitory potency than L. japonica. Differences of MIC values in $80\%$ ethanol extract of some species of marine algae were observed depending on test bacterial species, i.e., S. mutans KCTC 3300 or S. sobrinus KCTC 3307. Eighty percent ethanol extract of dried L japonica was fractionated with diethyl ether, chloroform, ethyl acetate, n-buthanol and water successively, The ether-soluble fraction had inhibitory effect on S. mutans KCTC 3300, however the inhibitory effects were not found in the other fractions. The MIC values of $80\%$ ethanol extract and ether fraction were 180 and 105 $\mu$g/mL respectively, while no significant inhibition activity of water-soluble fraction was found even when the fraction was added up to 5,500 $\mu$g/mL.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.83-89
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• 1994

The effects of inorganic selenium (Se), selenate and selenite on Se balance levels in the different ruminal fluid fractions were studied using Japanese Corriedale wethers with an average body weight of 47 kg. A $3{\times}3$ Latin square design was used with three animal, three periods and three treatments. In each period, there was 7 d dietary adjustment followed by 5 d total collection of urine and feces. Ruminal fluid samples were obtained at 0, 1, 3, 5 and 7 h postprandially on the final day of the collection period. The three dietary treatments were: (1) without Se supplementation (control); (2) with Se supplement as sodium selenate; and (3) sodium selenite at a rate of 0.2 mg Se/kg dietary DM. The basal diet was timothy hay (Phleum pratense L.) fed 2% of body weight/d. Results indicated that Se balance were higher (p < 0.05) for those animals under supplementation than those animals under control. Overall data gathered showed a similar digestion balance of selenate and selenite in sheep. Inorganic Se, both selenate and selenite produced positive Se contents of the ruminal feed particles and protozoa. Bacterial Se increased (p < 0.05) on the first three hours post-prandially in Se supplemented diets. Gross ruminal fluid fraction, although there was improvement on their Se content under the supplemented diets, the changes were insignificant over the control. free inorganic Se and Se in soluble protein of the ruminal fluid were not significantly different for selenate and selenite. Most of the Se in the ruminal fluids of the animals under supplementation were insoluble, indicating the influence of rumen environments on Se bioavaliability.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.71-75
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• 1990

The isolates biodigrading crude oil were examined to characterize thier properties. Isolates which were identified as Acinetobacter lwoffii G1, Klebsiella pneumoniae L25, Pseudomonas maltophilia N246, Xanthomonas campestris M12, and Xanthomonas sp. M28. The optimum concentration of crude oil was 0.15% for the bacterial growth. X. campestris M12, Xanthomonas sp. M28, and K. penumoniae L25 showed the maximal growth at the concentration of 3.5% sodium chloride, indicating that they were derived from sea water. Among the isolates, X. campestris M12, Xanthomonas sp. M28 specially utilized hexadecane and octane, and P. maltophilia N246 utilized octane with optimum concentration of 0.2-0.3% as sole carbon source. The utilization of components of saturate fraction by K. pneumoniae L25 was examined by gas-liquid chromatography. The short-chain saturates are used before the long chain ones although they almost disappear within 8 days of incubation at $30^{\circ}C$.

• Preventive Nutrition and Food Science
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• v.6 no.1
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• pp.57-61
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• 2001

Conjugated linoleic acid (CLA), when incorporated into mouse liver microsomal membranes, selectively inhibits the mutagenesis of 2-amino-3-methylimidazo[4,5-f] quinoline (IQ). Nine-week old female ICR mice were given (p.o.) 0.1 mL olive oil alone (control), 0.1 mL olive oil plus 0.1 mL linoleic acid, or 0.1 mL olive oil plus 0.1 mL CLA, twice weekly for four weeks. The animals were then sacrificed and liver S-9 fractions were prepared. Activation of IQ for mutagenesis by the liver S-9 from CLA-treated mice was significantly reduced in comparison wit liver S-9 from control or linolic acid-treated mice. By contrast, the activation of 7,12-dimethylbenz[a] anthracene (DMBA) and benzo[a] pyrene (BP) was unaffected. Hence, CLA incorporated into phospholipids may selectively affect cytochrome P450 isozymes responsible for activating IQ, but not those which activate BP or DMBA. The addition of free CLA or the methyl esters of CLA, linoleic acid, or oleic acid, to control S-9 inhibited the activation of all three mutagens (IQ, BP, and DMBA).

• Journal of Environmental Science International
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• v.16 no.7
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• pp.855-863
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• 2007

In order to understand the temporal distribution of pico- and nanoplankton and factors controlling its distribution at a station in Okkye Bay of Masan Bay located in the southern part of Korea, this study was conducted on two weeks interval from April 2005 to April 2006, and several abiotic and biotic factors were measured. During the study, picoplankton consisted of picoflagellates, cyanobacteria and heterotrophic bacteria, and nanoplankton consisted of nanoflagellates excluding dinoflagellates. The concentration of chlorophyll-a (chl-a) was a mean of $4.33\;{\mu}g/L$, and the nanoplanktonic ($<20\;{\mu}m$) chl-a size fraction was a mean of 39.5 % and significantly correlated with water temperature. The abundances of cyanobacteria and photosynthetic flagellates (PF) were means of $24.4{\times}10^{3}\;cells/mL\;and\;2.87{\times}10^{3}\;cells/mL$, respectively. The contribution of picoflagellates to the PF abundance varied among the sampling occasions and was a mean of 29 %, but to the PF carbon biomass was 2.6 % only. The PF abundance had significant relationships with water temperature, and silicate and TIN concentrations, suggesting that the PF abundance seemed to be primarily bottom-up regulated. The abundance of heterotrophic bacteria was a mean of $3.18{\times}10^{6}\;cells/mL$ and unlike other ecosystems it did not have relationships with chl-a and heterotrophic flagellates (HF), suggesting that bacterial abundance did not seem to be bottom-up or top-down regulated. HF mostly consisted of cells less than $5{\mu}m$ and its abundance was a mean of $2.71{\times}10^{3}\;cells/mL$. Of the HF abundance, picoflagellates occupied about 31 %, and occupied about 9 % of the HF carbon biomass. HF grazing activity on heterotrophic bacteria was relatively low and removed about 10 % of bacterial abundance, suggesting that HF might not be major consumers of bacteria and there seems to be other consumers in Okkye Bay. These results suggest that Okkye Bay may have a unique microbial ecosystem.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.144-150
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• 1997

We developed a simple and efficient method to prepare a Pseudomonas vaccine of outer membrane (OM) proteins free from lipopolysaccharide (LPS). A three step purification process including extraction, ultrafiltration and ultracentrifugation effectively removed LPS from the OM protein fraction. Approximately 2 mg of the OM proteins was obtained from 1 g of wet cell. LPS contaminant in the vaccine preparation was less than 0.003% (w/w) of protein and protease activity was not detectable. To achieve a wide range of protection, OM proteins prepared from four attenuated P. aeruginosa strains were mixed in equal amounts and used as a vaccine, which elicited in rabbits a high titer of antibody reactive to all of the seven Fisher types. The antisera from the immunized rabbit had a strong reactivity to vaccine proteins larger than 25 kDa. In a burned mouse infection model, immunization with the vaccine significantly enhanced bacterial clearance in the Pseudomonas infected skin. The vaccination also provided mice an excellent protection against Pseudomonas infection (11, 16). Data on antigenicity, mutagenicity, acute, subacute toxicity and pharmacological tests confirmed the safety of the vaccine (1, 3, 10, 12, 17). These data demonstrate that this method can be applied to manufacture a bacterial vaccine of OM proteins with safety and prophylactic efficacy at a practical low cost.

• Environmental Engineering Research
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• v.10 no.4
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• pp.181-190
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• 2005

Severe loss or hydrogen occurred in most anaerobic hydrogen fermentation reactors. Several selected methods were applied to suppress the consumption of hydrogen and increase the potential of production. As the first trial, pH shock was applied. The pH of reactor was dropped nearly to 3.0 by stopping alkalinity supply and on]y feeding glucose (5 g/L-d). As the pH was increase to $4.8{\pm}0.2,$ the degradation pathway was derived to solventogenesis resulting in disappearance of hydrogen in the headspace. In the aspect of bacterial community, methanogens weren't detected after 22 and 35 day, respectively. Even though, however, there was no methanogenic bacterium detected with fluorescence in-situ hybridization (FISH) method, hydrogen loss still occurred in the reactor showing a continuous increase of acetate when the pH was increased to $5.5{\pm}0.2$. This result was suggesting the possibility of the survival of spore fanning acetogenic bacteria enduring the severely acidic pH. As an alternative and additive method, nitrate was added in a batch experiment. It resulted in the increase of maximum hydrogen fraction from 29 (blank) to 61 % $(500\;mg\;NO_3/L)$. However, unfortunately, the loss of hydrogen occurred right after the depletion of nitrate by denitrification. In order to prevent the loss entangled with acetate formation, $CO_2$ scavenging in the headspace was applied to the hydrogen fermentation with heat-treated sludge since it was the primer of acetogenesis. As the $CO_2$ scavenging was applied, the maximum fraction of hydrogen was enhanced from 68 % to 87 %. And the loss of hydrogen could be protected effectively.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1706-1712
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• 2006

Because of the need for new antimicrobial substances with novel mechanisms of action, we report here the use of an Acinetobacter reporter system for high-throughput screening of active antimicrobial agents. The bioreporter Acinetobacter strain DF4/PUTK2 carrying luciferase genes luxCDABE was chosen because of its ecological importance and it is widespread in nature. This bioreporter is genetically engineered to emit light constitutively that can be measured in real time by luminometry. Hence, this reporter system was employed to determine the bacteriostatic actions of spent-culture supernatants derived from twelve bacterial isolates. Out of the results, the strongest bioluminescence inhibitory effect of the supernatants was recorded with Bacillus cereus strain BAC (S5). Subsequently, ethyl acetate extracts of extracellular products of strain BAC (S5) were separated by a thin-layer chromatography (TLC). Based on the bioluminescence inhibitory assay, three fractions were found to have antimicrobial activity. One fraction (C) having the strongest antimicrobial activity was further purified using TLC and characterized by IR, $^1H$ NMR, mass spectrometry, SDS-PAGE, and amino acid composition analysis. The results predicted the presence of 2-pyrrolidone-S-carboxylic acid (PCA) and the octadeconic-acid-like fatty acid. Fraction C also demonstrated a broad inhibitory activity on several Gram-negative and Gram-positive bacteria. In conclusion, the Acinetobacter reporter system shows great potential to be a reliable, sensitive, and real-time indicator of the bacteriostatic actions of the antimicrobial agents.

• Advances in Traditional Medicine
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• v.8 no.4
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• pp.339-348
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• 2008

Butea frondosa has been used traditionally as a topical formulation in the treatment of many diseases and disorders. Two compounds [BF-1 (crystalline flavonol quercetin) and BF-2 (tannin) from ethyl acetate fraction of ethanolic extract] were isolated from the bark of Butea frondosa. The stereostructures of the compounds were determined on the basis of chemical and physicochemical evidence. BF-1 and BF-2 were screened in vitro for possible antibacterial property against 112 bacteria comprising 3 genera of Gram-positive and 12 genera of Gram-negative types. It was found that both BF-1 and BF-2 exhibited inhibitory activity against several bacteria. Most of these strains were inhibited by BF-1 at $50-200\;{\mu}g/ml$, while BF-2 ($MIC_{50}$ $400\;{\mu}g/ml$) was much less active. The bacteria could be arranged in the decreasing order of sensitivity towards BF-1 in the following manner: S. aureus, Bacillus spp., Salmonella spp., Vibrio spp., Shigella spp., E. coli and Pseudomonas spp. The $MIC_{50}$ of the compound was $50\;{\mu}g/ml$ while the $MIC_{90}$ was $100\;{\mu}g/ml$. The decreasing order of sensitivity towards BF-2 was V. cholerae, Bacillus spp., S. aureus, V. parahaemolyticus, Salmonella spp. and Proteus spp. BF-1 was bactericidal in action. In vivo studies with this extract showed that it could offer statistically significant protection (p < 0.01) to mice challenged with a virulent bacterium. The inhibitory activity of Butea frondosa against Gram-positive and Gram-negative bacteria indicates its usefulness in the treatment of common bacterial infections. The potentiality of BF-1 as an antibacterial agent may be confirmed further by pharmacological studies.

• Archives of Pharmacal Research
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• v.24 no.1
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• pp.44-50
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• 2001

To search for cytotoxic components from Allium victoriallis , MTT assays on each extract and an isolated component, gitogenin 3-O-lycotetroside, were performed against cancer cell lines. Cytotoxicities of most extract were shown to be comparatively weak, though $IC_50$ values of $CHCl_3$fraction was found to be <31.3-368.4 $\mu\textrm{g}/ml$. From the incubated methanol extract at $36^{\circ}C, eleven kinds of organosulfuric flavours were predictable by CG-MS performance. The most abundant peak was revealed to be 2-vinyl-4H-1,3-dithiin(1) by its mass spectrum. Further, this extract showed significant cytotoxicities toward cancer cell lies. Silica gel column chromatography of the n-butanol fraction led to the isolation of gitogenin 3-O-lycotetroside (3) along with astragalin (4) and kaempferol 3, 4'-di-O-$\beta$-D-glycoside (5). This steroidal saponin exhibited significant cytotoxic activities ($IC_50$, 6.51-36.5 $\mu\textrm{g}/ml$) over several cancer cell lines. When compound 3 was incubated for 24 h with human intestinal bacteria, a major metabolite was produced and then isolated by silica gel column chromatography. By examining parent and prominent ion peak in FAB-MS spectrum of the metabolite, the structure was speculated not to be any of prosapogenins of 3, suggesting that spiroketal ring were labile to the bacterial reaction. These suggest that disulfides produced secondarily are the antitumor principles.