• Journal of Life Science
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• v.22 no.11
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• pp.1571-1586
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• 2012

On earth, there are about 5,400 kinds of mammals, of which about 1,000 kinds are herbivores. Among herbivores, about 250 kinds are known to be ruminants. As for cattle and sheep, which are ruminants, fermentation takes places mainly in their rumen; in contrast, for pigs and men, which are non-ruminants, fermentation takes place mainly in their caecum, colon, and rectum. As for the kind and dominance of rumen microorganisms, Bacteroidetes account for 51% and Firmicutes for 43%. As for the dominance of the large intestine microorganisms in men, Firmicutes account for 65% and Bacteroidetes for 25%. Cell wall components are decomposed by microorganisms, and short chain fatty acids (SCFAs) are generated through fermentation; the ratio of acetate, propionate, and butyrate generate is 60:25:15. Butyrate absorbed through the primary butyrate transporter MCT1 (mono carboxylate transports-1) in the intestines activates such SCFA receptors as GPR43 and GPR41. Butyrate has a strong anti-tumorigenic function. Butyrate is characterized by the fact that it has an effect on many cancer cells, contributes to the coordination of functions in the cells, and induces cancer apoptosis. Butyrate activates caspase but inhibits the activity of HDAC (histone deacetylase), so as to induce apoptosis. In addition, it increases p53 expression, so as to induce cell cycle arrest and apoptosis. Anti-inflammation actions of SCFA include the reduction of IL-8 expression in intestinal epithelial cells, the inhibition of NO synthesis, and the restraint of the activity of NF-${\kappa}B$ (nuclear factor ${\kappa}B$), so as to suppress the occurrence of cancers caused by inflammation. Butyrate plays an important role in maintaining physiological functions of intestinal mucous membranes and is used as a cure for inflammatory bowel disease (IBD).

• Journal of Forest and Environmental Science
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• v.23 no.1
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• pp.57-63
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• 2007

Anatomical characteristics of black and white charcoal of Quercus variabilis and Quercus mongolica manufactured by a Korean traditional kiln were investigated by scanning electron microscopy. In both charcoal, the earlywood vessels shrank in tangential direction, whereas the other cells didn't change. However, in the case of latewood vessels, black charcoal did not show tangential direction shrinkage, but white charcoal did. The wood fiber were changed severly in shape due to the excessive shrinkage. Tyloses in early wood vessel were still shown unchanged shape in both charcoals. Cell wall of ray parenchyma was observed and their shapes were severly distorted. Voids between ray parenchyma were observed in white charcoal, which maybe due to high temperature in white charcoal. Moreover, lumen diameters in the uniseriate ray and multiseriate ray were decreased at the high charring temperature. These results showed that the low charcoal yield of the white charcoal compared to the black charcoal was caused by decrease of cell dimensions as well as loss of wood components associated with the carbonization temperature.

• Analytical Science and Technology
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• v.30 no.3
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• pp.113-121
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• 2017

Now a day's rise of new antibiotic resistant bacterial strains is a global threat. Ethnic people of India have been employing Aphanamixis polystachya (Wall.) R. Parker wood extract in healing cancerous wounds. The aim of this study was to evaluate the antimicrobial activity and to identify the medicinally potent chemicals in the essential oil extract of A. polystachya. The antibacterial properties of various organic extracts were evaluated against a range of bacteria (gram-positive and gram-negative bacteria) based on the disc diffusion method and GC-MS based analysis for finding active oil extract components. All extracts of A. polystachya leaves showed potential antibacterial activity, notably ethyl acetate, while petroleum ether extracts revealed highly sensitive activity against all tested bacteria (zones of inhibition ranging from 8.83 to 11.23 mm). In addition, the petroleum ether extract had the lowest MIC value (32 to $256{\mu}g/mL$) against E. coli, S. lutea, X. campestris, and B. subtilis bacteria. The major compounds detected in oil [${\beta}$-elemene (16.04 %), ${\beta}$-eudesmol (12.78 %), ${\beta}$-caryophyllene (19.37 %), ${\beta}$-selinene (11.32 %), elemol (5.76 %), and ${\alpha}$-humulene (5.68 %)] are expected to be responsible for the potent antimicrobial activity. The results of this study offer valuable insights into the potent role of A. polystachya essential oil extract in pharmaceutical and antibiotic research.

• Journal of computational fluids engineering
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• v.16 no.4
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• pp.39-46
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• 2011

A numerical study of a turbulent natural convection in an enclosure with the lattice Boltzmann method (LBM) is presented. The primary emphasis of the present study is placed on investigation of accuracy and numerical stability of the LBM for the turbulent natural convection flow. A HYBRID method in which the thermal equation is solved by the conventional Reynolds averaged Navier-Stokes equation method while the conservation of mass and momentum equations are resolved by the LBM is employed in the present study. The elliptic-relaxation model is employed for the turbulence model and the turbulent heat fluxes are treated by the algebraic flux model. All the governing equations are discretized on a cell-centered, non-uniform grid using the finite-volume method. The convection terms are treated by a second-order central-difference scheme with the deferred correction way to ensure accuracy and stability of solutions. The present LBM is applied to the prediction of a turbulent natural convection in a rectangular cavity and the computed results are compared with the experimental data commonly used for the validation of turbulence models and those by the conventional finite-volume method. It is shown that the LBM with the present HYBRID thermal model predicts the mean velocity components and turbulent quantities which are as good as those by the conventional finite-volume method. It is also found that the accuracy and stability of the solution is significantly affected by the treatment of the convection term, especially near the wall.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.391-399
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• 2011

Free fatty acids (FFAs) are known to have bacteriocidal activity and are important components of the innate immune system. Many FFAs are naturally present in human and animal skin, breast milk, and in the bloodstream. Here, the therapeutic potential of FFAs against methicillin-resistant Staphylococcus aureus (MRSA) is demonstrated in cultures and in mice. Among a series of FFAs, only oleic acid (OA) (C18:1, cis-9) can effectively eliminate Staphylococcus aureus (S. aureus) through cell wall disruption. Lauric acid (LA, C12:0) and palmitic acid (PA, C16:0) do not have this ability. OA can inhibit growth of a number of Gram-positive bacteria, including hospital and community-associated MRSA at a dose that did not show any toxicity to human sebocytes. The bacteriocidal activities of FFAs were also demonstrated in vivo through injection of OA into mouse skin lesions previously infected with a strain of MRSA. In conclusion, our results suggest a promising therapeutic approach against MRSA through boosting the bacteriocidal activities of native FFAs, which may have been co-evolved during the interactions between microbes and their hosts.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1381-1385
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• 2013

The centipede Scolopendra subpinipes mutilans is a medicinally important arthropod species. However, its transcriptome is not currently available and transcriptome analysis would be useful in providing insight into a molecular level approach. Hence, we performed de novo RNA sequencing of S. subpinipes mutilans using next-generation sequencing. We generated a novel peptide (scolopendrasin II) based on a SVM algorithm, and biochemically evaluated the in vitro antimicrobial activity of scolopendrasin II against various microbes. Scolopendrasin II showed antibacterial activities against gram-positive and -negative bacterial strains, including the yeast Candida albicans and antibiotic-resistant gram-negative bacteria, as determined by a radial diffusion assay and colony count assay without hemolytic activity. In addition, we confirmed that scolopendrasin II bound to the surface of bacteria through a specific interaction with lipoteichoic acid and a lipopolysaccharide, which was one of the bacterial cell-wall components. In conclusion, our results suggest that scolopendrasin II may be useful for developing peptide antibiotics.

• Molecules and Cells
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• v.40 no.12
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• pp.935-944
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• 2017

More than 50% of sepsis cases are associated with pneumonia. Sepsis is caused by infiltration of bacteria into the blood via inflammation, which is triggered by the release of cell wall components following lysis. However, the regulatory mechanism of lysis during infection is not well defined. Mice were infected with Streptococcus pneumoniae D39 wild-type (WT) and lipase mutant (${\Delta}lipA$) intranasally (pneumonia model) or intraperitoneally (sepsis model), and survival rate and pneumococcal colonization were determined. LipA and autolysin (LytA) levels were determined by qPCR and western blotting. S. pneumoniae Spd_1447 in the D39 (type 2) strain was identified as a lipase (LipA). In the sepsis model, but not in the pneumonia model, mice infected with the ${\Delta}lipA$ displayed higher mortality rates than did the D39 WT-infected mice. Treatment of pneumococci with serum induced LipA expression at both the mRNA and protein levels. In the presence of serum, the ${\Delta}lipA$ displayed faster lysis rates and higher LytA expression than the WT, both in vitro and in vivo. These results indicate that a pneumococcal lipase (LipA) represses autolysis via inhibition of LytA in a sepsis model.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1681-1688
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• 2004

Soaked and pasteurised wheat straw was inoculated with five species of Pleurotus fungi (coded P-21, P-30, P-41, P-60 and P-90), packed in polyethylene bags and incubated in a fermentation chamber for 21 days. The chemical composition, in vitro digestibility and in sacco degradability of the treated and untreated straw were estimated using a complete randomised design consisting of six treatments and four replicates. In a feeding trial, in vivo digestibility and voluntary intake were determined in bulls, using a $3{\times}3$change over design. Dietary treatments were: 1) untreated wheat straw (UWS) as control; 2) fungal treated (P-41) wheat straw before mushroom formation (FTWS); 3) spent wheat straw (SPWS) after mushrooms were harvested. Apart from P-90, fungal treatment significantly (p<0.05) increased the crude protein (CP) and reduced the cell wall components of the straw. The in vitro dry mater and organic mater digestibility significantly (p<0.05) increased in the treated straw particularly with the treatments of P-41 and P-60. The in situ degradability and in vivo digestibility of DM and OM were significantly (p<0.05) increased in treated straws with the highest values observed for treatment P-41. The intake of DM, OM and digestible organic mater (DOM) were significantly (p<0.05) increased in cows fed FTWS.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.826-831
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• 1999

${\beta}-Glucan$, one of the major cell wall components of Saccharomyces cerevisiae, is known to enhance the immune function, especially by activating macrophages. Accordingly, in an effort to develop a safe and efficient immune stimulatory agent, we prepared crude ${\beta}-glucan$ (glucan-p1) and partially purified ${\beta}-glucan$ that was free of mannoproteins (glucan-p2), and evaluated their effect on both the macrophage function and resistance to E. coli-induced peritonitis. To investigate the function of the macrophages, phagocytosis, $TNF-{\alpha}$ secretion, oxygen burst, and the expression of cytokine genes such as $IFN-{\gamma}$ and IL-12 were analyzed. Glucan-p2 markedly stimulated the macrophages with all these parameters. Glucan-p1, however, did not stimulate phagocytosis, yet it induced $TNF-{\alpha}$ secretion, oxygen burst, and the expression of $IFN-{\gamma}$ and IL-12, although less efficiently than glucan-p2. Finally, to test the in vivo protective effect of {\beta}-glucan against infection, the survival of mice from E. coli-induced peritonitis was investigated. After 24 h of the peritoneal challenge of E. coli, all of the mice treated with glucan-p2 survived whereas none survived in the control group. Glucan-p1 showed only a marginal effect in protecting the mice. These results suggest that mannoprotein-free gluean-p2, but not gluean-p1, can serve as an effective immune-stimulating agent.

• Journal of Life Science
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• v.25 no.12
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• pp.1450-1457
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• 2015

To overcome the depletion of fossil fuels and environmental problems in future, the research and production of biofuels have attracted attention largely. Thermophilic microorganisms produce effective and robust enzymes which can hydrolyze plant biomass and survive under harsh bioprocessing conditions. Caldicellulosiruptor bescii, which can degrade unpretreated plants and grow on them, is the one of the best candidates for consolidated bioprocessing (CBP). C. bescii can hydrolyze pectin efficiently as well as the major plant cell wall components, cellulose and hemicelluloses. Many glycosyl hydrolases and carbohydrate lyases with multidomain structure play an important role in plant biomass decomposition. Recently genetic tools for metabolic engineering of C. bescii have developed and bioethanol production from unpretreated biomass is achieved in C. bescii. Here, we review the recent studies for biomass degradation by C. bescii and bioethanol production in C. bescii in order to provide information about metabolic engineering of themophilic bacteria and biofuel development.