• Microbiology and Biotechnology Letters
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• v.9 no.2
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• pp.83-89
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• 1981

Several kinds of organic acids, alcohols, aromatic compounds and sugars as carbon sources were tested in order to produce the cell mass of Rhizopus oryzae which is used in part of food processing or organic acid fermentation. Sodium acetate among them was good enough for carbon source as well as glucose under the concentration of one percent. All nitrogenous substances tested such as ammonium, nitrate or organic nitrogen compounds were well used by this strain of Rhizopus oryzae as nitrogen source. Ammonium sulfate among inorganic nitrogen compounds was most utilized as a nitrogen source in glucose or acetate medium. This strain did not require any growth factors such as yeast extract. The following composition of medium was therefore determined in order to produce the cell mass of Rhizopus oryzae: Na-acetate 1 %, (NH$_4$)$_2$SO$_4$ 0.2%, $K_2$HPO$_4$ 0.05%, MgSO$_4$.7$H_2O$ 0.01%, NaCl 0.01% (PH 5.5). The cell wall of mycelium grown in above medium was lysed optimally at pH 6.5 and 5$0^{\circ}C$ by the action of Strepzyme 115-5. On producing protoplast from mycelium by enzymatic action, almost all of the mycelium was damaged after 4hrs of treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1228-1233
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• 1999

A study was conducted on four maize cultivars to determine the dry matter and fibre digestibility as influenced by advancing plant age. Samples of maize cultivars Akbar, Neelum, UM-81 and IZ-31 were harvested at weekly intervals/ growth stages. The samples of morphological fractions such as leaf and stem were also collected at various growth stages. Whole mixed fodder and different fractions of maize plant were analysed for their chemical composition and in vitro digestibility. The results showed that in vitro dry matter digestibility (IVDMD) of whole maize plant, leaf and stem decreased significantly with advancing stage of maturity. Digestibility of NDF, ADF, hemicellulose and cellulose decreased significantly in all plant parts with advancing plant age/growth stages. Maximum values for the digestibility of dry matter and various cell wall constituents were observed in leaf, followed by whole plant and stem fractions. Cultivars were observed to have significant effect of IVDMD and digestibility of NDF, ADF and cellulose in all plant fractions. The results indicated that digestibility of maize fodder was affected by stage of maturity and cultivars. However, maturity had a greater effect on digestibility in all plant fractions than did cultivars. Dry matter contents were found to be significantly and negatively correlated with IVDMD of whole plant and its leaf and stem fractions. Based on correlations, regression equations were computed to predict IVDMD.

• BMB Reports
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• v.38 no.5
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• pp.507-516
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• 2005

Antimicrobial peptides (AMPs) have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum. Their amino acid composition, amphipathicity, cationic charge, and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of AMP activity, their relevance to resolving how peptides damage and kill microorganisms still needs to be clarified. Moreover, many AMPs employ sophisticated and dynamic mechanisms of action to carry out their likely roles in antimicrobial host defense. Recently, it has been speculated that transmembrane pore formation is not the only mechanism of microbial killing by AMPs. In fact, several observations suggest that translocated AMPs can alter cytoplasmic membrane septum formation, reduce cell-wall, nucleic acid, and protein synthesis, and inhibit enzymatic activity. In this review, we present the structures of several AMPs as well as models of how AMPs induce pore formation. AMPs have received special attention as a possible alternative way to combat antibiotic-resistant bacterial strains. It may be possible to design synthetic AMPs with enhanced activity for microbial cells, especially those with antibiotic resistance, as well as synergistic effects with conventional antibiotic agents that lack cytotoxic or hemolytic activity.

• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.588-595
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• 2009

A bacterial strain, YK-2, was isolated as a producer of trans glutaminase from a forest soil sample of Daegu, Korea. The isolate showed a G+C content of 72.7 mol%, contained meso-$A_2pm$ as the cell-wall amino acid, and possessed menaquinone MK-9 ($H_6$) and menaquinone MK-9 ($H_8$) at a ratio of 6:4. The chemotaxonomic analysis, as well as phylogenetic analysis based on the 16S rDNA sequence, identified the isolate as a member of Streptomyces platensis. For transglutaminase production, the optimum medium composition was determined to be 2% glucose, 1% polypeptone, 1% soy tone, and 0.1% $MnCl_2$. The transglutaminase was stable within the pH range of 5.0-9.0 and $30-45^{\circ}C$, and the optimum pH and temperature were pH 8.0 and $45^{\circ}C$, respectively, without any requirement for $Ca^{2+}$.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.49-55
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• 2011

Thirty Streptomyces sp. and 200 Bacillus sp. isolated from Korean soils and traditional foods were screened for their abilities to inhibit ${\alpha}$-glucosidase and produce 1-deoxynojirimycin (DNJ). This screening identified a Bacillus sp. bacterium that strongly inhibited ${\alpha}$-glucosidase and produced high levels of DNJ from Chungkookjang, a Korean traditional food. The bacterium was characterized in terms of its biochemical and molecular biological properties such as sugar utilization, cellular quinone composition, cell wall fatty acid composition, and 16S rDNA sequence. In addition, scanning electron microscopy was used to visualize the morphology of the bacterium. These analyses identified the bacterium as B. subtilis, a bacterium with Generally Recognized as Safe (GRAS) status. The selected strain was named B. subtilis MORI.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1722-1724
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• 2003

The possibility of using cotton stems as a roughage source in animal feeding was explored. Ground cotton stems (T2 and T3) or stems treated with 0.5% urea (T4 and T5) were ensiled with pearl millet green fodder in double lined plastic bags of 3 kg capacity for 50 days. Formic acid (0.4% v/v) was sprayed on T3 and T5 silages. The treatments were compared with pearl millet silage alone (T1) which constituted the control. All the bags were placed in the silo pit of pearl millet silage. Results indicated that urea treatment of cotton stems increased and formic acid application reduced dry matter loss of the silages. Inclusion of cotton stems in the silage significantly (p<0.05) increased CF, ADF, cellulose and ADL due to its higher cell wall content. The hemicellulose was significantly lower in T3 (16.7%) and T5 (22.52%) as compared to T2 (23.45%) and T4 (24.6%) due to formic acid application. Ammoniation significantly increased NH3-N content in T4 (0.202%) and formic acid controlled NH3-N level in T5 (0.107%).The in sacco dry matter digestibility was significantly higher (p<0.05) in formic acid preserved silages T3 and T5 (47.73 and 47.93%) as compared to silages without formic acid (44.94 and 41.22 %) in T2 and T4 respectively, but lower than T1 (54.39%). It is concluded that cotton stems can be ensiled with pearl millet fodder in 1:4 ratio with or without urea treatment. Formic acid application further increases the silage quality.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.517-522
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• 2007

The aim of this study was to compare in vitro gas production kinetics, metabolizable energy (ME), organic matter digestibility (OMD) and microbial protein (MP) production of widely used legume hays in ruminant nutrition in Turkey. Gas production were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation p = a+b ($1-e^{-ct}$). There were significant differences among legume hays in terms of chemical composition. The crude protein content of legume hays ranged from 11.7 to 18.6% of dry matter (DM); crude fat from 2.1 to 3.5% DM; neutral detergent fiber from 35.6 to 52.0% DM; acid detergent fiber from 32.0 to 35.5% DM and acid detergent lignin 1.7 to 11.0% DM. Total gas production after 96 h incubation ranged between 61.67 and 76.00 ml/0.200 g of substrate. At 24, 72 and 96 h incubation the total gas production for common vetch were significantly (p<0.01) higher than those of the other legume hays. The ME, OMD and MP of legume hays ranged from 9.09 to 11.12 MJ/kg DM, 61.30 to 75.54% and 90.35 to 138.05 g/kg DM, respectively. The ME, OMD and MP of common vetch was significantly (p<0.01) higher than those of the other hays due to low cell-wall contents and high crude protein. At the end of the experiment, differences in chemical composition of legume hays resulted in the differences in the in vitro gas production, gas production kinetics and the estimated parameters such as ME, OMD and MP. Common vetch can be recommended to hay producers and ruminant breeders, due to high ME, OMD and MP production.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.800-805
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• 2012

Rice straw is an important roughage resource for ruminants in many rice-producing countries. In this study, a rice brittle mutant (BM, mutation in OsCesA4, encoding cellulose synthase) and its wild type (WT) were employed to investigate the effects of a cellulose synthase gene mutation on rice straw morphological fractions, chemical composition, stem histological structure and in situ digestibility. The morphological fractions investigation showed that BM had a higher leaf sheath proportion (43.70% vs 38.21%, p<0.01) and a lower leaf blade proportion (25.21% vs 32.14%, p<0.01) than WT. Chemical composition analysis showed that BM rice straw was significantly (p<0.01) higher in CP (crude protein), hemicellulose and acid insoluble ash (AIA) contents, but lower in dry matter (DM), acid detergent fiber (ADFom) and cellulose contents when compared to WT. No significant difference (p>0.05) was detected in neutral detergent fiber (NDFom) and ADL contents for both strains. Histological structure observation indicated that BM stems had fewer sclerenchyma cells and a thinner sclerenchyma cell wall than WT. The results of in situ digestion showed that BM had higher DM, NDFom, cellulose and hemicellulose disappearance at 24 or 48 h of incubation (p<0.05). The effective digestibility of BM rice straw DM and NDFom was greater than that of WT (31.4% vs 26.7% for DM, 29.1% vs 24.3% for NDFom, p<0.05), but the rate of digestion of the slowly digested fraction of BM rice straw DM and NDF was decreased. These results indicated that the mutation in the cellulose synthase gene could improve the nutritive value of rice straw for ruminants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.2
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• pp.103-108
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• 1987

The experiment was carried out to determine the optimum application rate of liquid waste from methane fermentation (LW) and its effect on botanical composition, dry matter yields and nutrient quality of pasture mixtures. Experimental fields was designed as a randomized block treated with NPK chemical fertilizer (NPK = 28-20-24 kg/lOa), NPK + Water 28 ton, 112 NPK + LW 28 ton, 112 NPK + LW 42 ton, LW 28 ton, LW 42 ton and LW 56 ton/lOa at Livestock Experiment Station in Suweon, 1985. The results obtained are summarized as follows: 1. Vegetation of introduced pastures, both in grasses and legumes, was markedly increased in the plots treated with methane-liquid waste. However, heavy application of liquid waste tended to increase of native weeds such as Polygronum spp., Rumex spp. and Lactuca spp. 2. Crude protein contents was increased in the plants applied with liquid waste, but NFE was decreased compared with those of chemical fertilizer applied. The concentrations of crude fat and crude fibre were, however less affected by the fertilizer resource. Among cell-wall constituents, cellulose content was decreased as the liquid waste application rate increased, while hemicellulose showed a negative association. 3. Productivity of the pasture was increased as the liquid waste application rate increased. The highest dry matter yields was obtained in the plot treated with LW 42 ton/lOa by 71 1 kg/lOa, which shows about 71% increments compared with those of chemical fertilizer treated. Net energy yields, both in starch value and NEL, were also markedly increased under liquid waste application. As a results, the optimum application rate of methane-liquid waste was found to be 42 ton in 10 a.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.102-107
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• 2002

This study deals with a physical properties of Larch(Larix kaemferi Carr.) treated at temperatures above 100℃. Treatment conditions of this experiment were operated at regular intervals of 20℃ at temperature up to 180℃ for 10, 30, 60 and 90 minutes by using the bomb, respectively. The results of this study were as follows : 1) The density was decreased with increasing the times and temperatures of steaming. 2) It was considered that the steaming treated specimen's higher shrinkage compared to control was due to change of composition and structure in cell wall. 3) The warpage of half edge grain specimen was decreased by high temperature steaming.