• Journal of fish pathology
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• v.10 no.1
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• pp.1-14
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• 1997

Major object of this study was to investigate the causative organism of th e diseased cultured fingerling of sea bass, L japonicus. The experimental results are summarized as follows ; Staphylococcus epidermidis, isolated from the liver, kidney, spleen and brain, was considered to be the causative organism. External symptoms of this disease were congestion and hemorrhages in eyes. Anatomical symptoms were hemorrhage of brain, congestion of liver, and slight swelling of kidney and spleen. Growth of the isolates was good on BHIA, HIA and Staphylococcus No. 110. The growth occurred at a range(optimum) of $10\sim45^{\circ}C(35\sim40^{\circ}C)$, 0~9% (1~3%) of NaCl concentration and pH 4~10(8). DNase and coagulase production of all isolated strains were nagative, but was positive in hemolysis. Urease was positive reaction, and novobiocin resistance was nagative. Acid was produced anaerobically from glucose and maltose. Acid was produced aerobically from glucose, galactose, sucrose, maltose and dextrine. But gas was not produced from any carbohydrates. When the isolated strain was injected intramuscularly on fingerling of sea bass, L japonicus, it had virulence at $1.7{\times}10^{10}$ viable cells/$m\ell$ for all fish examined but no virulence at $1.7{\times}10^4$ viable cells/$m\ell$. Bacitracin, Erythromycin and Nofloxacin were observed as bacteriostatic agents to the strain, but Colistin, Gentamicin and Nalidixic acid were not. There were remarkable congestion of the brain, regressive necrosis of the liver, and showed necrosis of the epithelial cells of renal tubules in kidney tissues.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.40-46
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• 2006

Galactose joined to glucose by a $\beta(1\rightarrow4)$ glycosidic bond makes lactose and this disaccharide is rich in milk. It is known that lacotse is hydrolyzed to each monomeric sugar by either lactase in human or $\beta-galactosidase$ in bacteria. Ingestion of milk by lactase-deficient persons causes a temporary diarrhea and subsequent chronic diarrhea results in colitis with chronic inflammation. We isolated a $\beta-galactosidase$ producing psycrotolerant strain AS-20 from near cattle shed and investigated the growth at various temperature conditions. Whereas Escherichia coli strains did not grow at $10^{\circ}C$, the AS-20 strain could grow well at this low temperature and showed optimal growth at $30^{\circ}C$. The isolated strain was identified as 97% Hafnia alvei by biochemical properties. This strain could ferment glucose, lacotse, maltose, mannitol, xylose, ONPG, rhamanose and L-arabinose, and decarboxylate lysin and ornithine. To confirm the identity of isolated strain we amplified 16S rDNA by PCR and searched similarity of the 1426 bp DNA sequcence with Genbank database. The strain AS-20 showed 99% similarity with Hafnia alvei. The activity of $\beta-galactosidase$ was 1.5 times higher when the cell was grown at 10 or $20^{\circ}C$ than at $30^{\circ}C$. The highest enzyme activity of AS-20 was also much higher than that of E. coli, which was grown at $30^{\circ}C$.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.41-46
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• 1986

Exogenous factor and nutrients affecting for conidial germination of Colletetrichum dematium f. sp. capsicum causing red pepper anthracnose were studied by slide germination test. Optimum temperature of conidial germination was at $28^{\circ}C$, ranging 15 to $35^{\circ}C$. Optimum pH was at 5.5, ranging 4.5 to 8.0, and more than 90% of relative humidity (RH) was optimum. Poor conidial germination of the fungus was observed on sterile distilled water, but potato sucrose broth (PSB), red pepper fruit broth (RPFB), green pepper fruit broth (GPFB) and pepper leaf broth (PLB) furnished a satisfactory nutrients for conidial germination. Exogenous supply of carbon and nitrogen sources were essential for conidial germination, while potassium, phosphorous and sulfur were not evident as that for carbon and nitrogen. Soluble starch was the most suitable as a carbon source for conidial germination and followed by D-glucose, D-galactose and lactose in that order. Maximum germination was attained in the $1{\times}10^4$ conidia per ml. Germination was decreased with increment of conidial concentration, and in the density of $5{\times}10^4$ conida per ml, germination was nearly supipressed. It suggested existing a self-inhibitor. Non-washed conidia germinated more than washed conidia, and conidial germination was also gradually decreased by increasing conidial density.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.411-415
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• 2009

Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.89-119
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• 2004

This study was conducted to isolate lactobacilli having probiotic characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from 80 healthy persons (infants, children and adults). And bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. By estimation above characteristics, the strains No. 27, which was isolated from adult feces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing. It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at $37^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by $0.9{\sim}1.0%$ at $37^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced $23{\sim}38%$ of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 hours at $37^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with $15{\sim}25$ mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. Purified ${\alpha}$-galactosidase was obtained by DEAE-Sephadex A-50 ion exchange chromatography, Mono-Q ion exchange chromatography and HPLC column chromatography from L. salivarius subsp. salivarius 27. The specific activity of the purified enzyme was 8,994 units/mg protein, representing an 17.09 folds purification of the original cell crude extract. The molecular weight of enzyme was identified about 53,000 dalton by 12% SDS-PAGE. Optimal temperature and pH for activity of this enzyme were $40^{\circ}C$ and 7.0 respectively. The enzyme was found to be stable between 25 and $50^{\circ}C$. ${\alpha}$-galactosidase activity was lost rapidly below pH 5.0 and above pH 9.0. This enzyme was liberated galactose from melibiose, raffinose, and stachyose, and also the hydrolysis rate of substrate was compound by HPLC. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.345-356
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• 1996

Properties of enzymatic hydrolysates from ascidian tunic were assessed on supernatant ratio, solid yields and solid concentration. The concentartion of solid and yields in the extracts were increased as the enzyme concentration raised from $100\;{\mu}l\;to\;1000{\mu}l$ during the extraction period. The optima concentration and reaction time of each enzyme on digestion were $400\;{\mu}l$ 60 minutes, through treated with Duncan's multiple test. The percent of yields of solid, protein and carotenoids for 60 minutes extraction at $400\;{\mu}l$ were $32.32\%,\;1.34\%\;and\;74.60\;mg\%$, respectively, in Viscozyme systems. The extracts were composed with many kinds of carbohydrates such as arabinose, ribose, xylose, galactose, glucose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine. Aspartic and glutamic arid were noted as predominant amino acids in all parts. Amino acid profiles of various ascidian tunic part were similiar to each other, but most of essential amino acids content of inter coat was higher than that of root and tunic (body). About sixty six fatty acids components were observed, and their distribution among neutral and polar lipids was compared. The main fatty acids were found to be 14:0, 16:0, 16:1n7, 18:0, 18:1n9, 18:1n7, 18:2n6, 20:5n3, and 22:6n3.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.586-593
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• 2004

Efficient extraction method of crude protein-bound polysaccharide (CPBP) from Agaricus blasei Murill was established. CPBP yields by ultrasonic and hot water extractions were 13.0 and 7.8%, respectively. Pressure extraction for 3 hr gave the highest ${\beta}-glucan$ content; no significant difference was observed between 2 and 3 hr extraction. Four volumes added ethanol gave the highest yields of CPBP and ${\beta}-glucan$ contents at 10.89 and 35.97%, respectively. Decomposition temperature of CPBP was $240-365^{\circ}C$, showing relatively good thermal stability. In SRB (sulforhodamine B) assay, CPBP treatment at $1,000\;{\mu}g/mL$ for 72 hr inhibited proliferations to A549, MCF-7, and AGS cancer cells by 43.9, 21.4, and 32.5%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.752-757
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• 2003

This study was carried out in order to develop the method for isolation of red ginseng acidic polysaccharide (RGAP) haying immunomodulating antitumor activity from red ginseng by-product. The red ginseng by-product was obtained from red ginseng residues produced in processing of red ginseng ethanol extract. The yield of RGAP isolated by ultrafiltration was 20.9%. The active substance (GFP) was purified by DEAE-sepharose column chromatography RGAP induced nitric oxide (NO) exhibited tumoricidal activities against P8l5 (mastocytoma) tumor cells. Acid-hydrolyzed RGAP fragments were shown four to five spots. These sopts showed the same R$_{f}$ values with sugars designated as rhamnose, glucose, glactose and glucuronic acid. Some physico-chemical properties of RGAP were investigated. pH and dry reduction content at 105$^{\circ}C$ were 4.74 and 4.72%, respectively. Crude protein, ash and Pb contents were 3.30%, 4.74% and 2.30 ppm. These results suggest that we will be able to produce RGAP from red ginseng by-product by ultrafiltration in a large scale.e.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.355-360
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• 2009

In this study, the arylsulfatase gene (astA, 984 bp ORF) from Pseudoalteromonas carrageenovora genome was expressed on the cell surface of S. cerevisiae by fusing with Aga2p linked to the membrane anchored protein, Aga1p. The constructed plasmid, pCTAST (7.1 kb), was introduced to S. cerevisiae EBY100 cell, and yeast transformants on YPDG plate showed the hydrolyzing activity for 4-methylumbelliferyl-sulfate and p-nitrophenyl-sulfate. When S. cerevisiae EBY100/pCTAST was grown on YPDG medium, the arylsulfatase activity of cell pellet reached about 1.2 unit/mL, whereas no extracellular arylsulfatase activity was detected. The DNA ladder in agarose prepared from agar by this recombinant arylsulfatase showed similar resolution and migration patterns with a commercial agarose. This results revealed that arylsulfatase expressed on the cell surface of S. cerevisiae could be applicable to the economic production of electrophoretic-grade agarose.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.157-162
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• 2009

An agar-liquefying bacteria (SC-22), which produces a diffusible agarase that caused agar softening around the colony was isolated from Daecheong lake in Korea. Chemotaxanomic and phylogenetic analyses based on 16S rRNA gene sequences revealed the strain was classified as Cellvibrio mixtus SC-22. The isolate SC-22 showed maximal extracellular agarase activity with 58.5 U/mL after 48 h cultivation in the presence of 0.2% agar. It was observed that the isolate produced two kinds of extracellular and three kinds of intracellular isoenzymes. The major agarase was purified from the culture filtrate of agarolytic bacteria by ammonium sulfate precipitation, anion exchange and gel filtration column chromatographic methods. The molecular mass of the purified enzyme was estimated to be 25 kDa by SDS-PAGE. The optimum pH and temperature of the purified enzyme were pH 7.0 and $50^{\circ}C$, respectively. The agarase activity was activated by $Fe^{2+}$, $Na^+$ and $Ca^{2+}$ ions while it was inhibited by $Hg^{2+}$, $Mn^{2+}$ and $Cu^{2+}$ at 1 mM concentration. The predominant hydrolysis product of agarose by the enzyme was galactose and disaccharide on TLC, indicating the cleavage of $\beta$-1,4 linkage in a random manner. The enzyme showed high substrate specificity for only agar and agarose among various polysaccharides.