• The Korean Journal of Mycology
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• v.37 no.2
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• pp.150-154
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• 2009

The diversity of microflora according to growth stage of Pleurotus ostreatus and the correlation between microbe and medium fermentation were investigated. In farmhouse I, the aerobic bacteria and fungi as longer of growing period were increased. And, thermophilic bacteria and fluorescent Pseudomonas sp. showed high density at the early stage of spawn inoculation. The thermophilic actinomycetes were distributed evenly during all the growing period, but mesophilic actinomycetes were not observed. In farmhouse II, thermophilic actinomycetes were not observed in fermented medium and density of fungi were suddenly increased at 60 days after spawn inoculation. And also, mushrooms can hardly be harvested due to Penicillium spp. After medium fermentation, density of aerobic bacteria, thermophilic bacteria, and fluorescent Pseudomonas sp. was higher at farmhouse I than those of farmhouse II. In farmhouse I, Bacillus sp. and Pseudomonas sp. dominated at early stage of mushroom growth but as time goes by, density of Bacillus sp. was higher than the others. And also, the kind of microbe showed a few at early stage of mushroom growth but increased as time goes by. In farmhouse II, Bacillus sp. was dominated at early stage of mushroom growth. And the growth of Bacillus sp. and Pseudomonas sp. showed intersect aspect each other in the farmhouse I but Bacillus sp. dominated during all growth periods in the farmhouse II.

• Journal of Korean Society on Water Environment
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• v.27 no.3
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• pp.334-341
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• 2011

The free residual chlorine of tap water samples, collected from 266 faucets on the water pipe network in Daegu City, was between 0.1 and 0.79 mg/L. On microorganic tests, general bacteria and the coliform goup were not detected and thus the tap water was turned out to be fit to drink. In particular, samples of which free residual chlorine was 0.1 mg/L and over were cultured in R2A agar media at $25^{\circ}C$ for 7 days, and as a result heterotrophic bacteria were detected in 65.9% of samples; (1). The closer tap water got to the faucet from the stilling basin, the lower residual chlorine concentration became but the more the bacterial count became. And, more bacteria were detected in the R2A agar medium than in the PCA medium. (2). In the case of separated strains, most colonies were reddish or yellowish. 16S rRNA sequence was identified as Methylobacterium sp. and Williamsia sp., and yellow strain was identified as Sphingomonas sp., Sphingobium sp., Novosphingobium sp., Blastomonas sp., Rhodococcus sp. and Microbacterium sp. White strain was identified as Staphylococcus sp. (3). Sterilized tap water in polyethylene bottles was inoculated with separated strain and was left as it was for 2 months. As a result, bio-film was observed in tap water inoculated with Methylobacterium sp. and Sphingomonas sp. It was found that heterotrophic bacteria increased when free residual chlorine was removed from tap water in the water pipe network. Thus, there is a need to determine a base value for heterotrophic bacteria in order to check the cleanliness of tap water in the water pipe network.

• Genomics & Informatics
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• v.21 no.3
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• pp.35.1-35.12
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• 2023

The Bacillus cereus group, also known as B. cereus sensu lato (B. cereus s.l.), is composed of various Bacillus species, some of which can cause diarrheal or emetic food poisoning. Several emerging highly heat-resistant Bacillus species have been identified, these include B. thermoamylovorans, B. sporothermodurans, and B. cytotoxicus NVH 391-98. Herein, we performed whole genome analysis of two thermotolerant Bacillus sp. isolates, Bacillus sp. B48 and Bacillus sp. B140, from an omelet with acacia leaves and fried rice, respectively. Phylogenomic analysis suggested that Bacillus sp. B48 and Bacillus sp. B140 are closely related to B. cereus and B. thuringiensis, respectively. Whole genome alignment of Bacillus sp. B48, Bacillus sp. B140, mesophilic strain B. cereus ATCC14579, and thermophilic strain B. cytotoxicus NVH 391-98 using the Mauve program revealed the presence of numerous homologous regions including genes responsible for heat shock in the dnaK gene cluster. However, the presence of a DUF4253 domain-containing protein was observed only in the genome of B. cereus ATCC14579 while the intracellular protease PfpI family was present only in the chromosome of B. cytotoxicus NVH 391-98. In addition, prophage Clp protease-like proteins were found in the genomes of both Bacillus sp. B48 and Bacillus sp. B140 but not in the genome of B. cereus ATCC14579. The genomic profiles of Bacillus sp. isolates were identified by using whole genome analysis especially those relating to heat-responsive gene clusters. The findings presented in this study lay the foundations for subsequent studies to reveal further insights into the molecular mechanisms of Bacillus species in terms of heat resistance mechanisms.

• Journal of Aquaculture
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• v.11 no.2
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• pp.231-240
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• 1998

Tetraselmis is widely used as a live food because of its easy handling, high nutrient, large size and wide tolerant range of temperature and salinity. In order to find the optimum Tetraselmis species for mass culture in Korea, five species of this microalgae were examined on size, optimum culture condition ${\textperthousand}$s, $^{\circ}C.$) and nutrient composition. The results obtained were as follows: Among five species of Tetraselmis, T. sp.(Haeundae) was the largest(major axis $17.6{\pm}1.87^{\mu}$m, mean cell volume 727${\mu}$m), and T. sp. (China) the smallest (major axis $14.6{\pm}1.46^{\mu}$m, mean cell volume 625m). Tetraselmis was very eurythermal and euryhaline species. But optimum temperature and salinity for growth were 24~$30^{\circ}C.$ and 27~30${\textperthousand}$, respectively. Among five species of Tetraselmis, T. sp. (China) seemed to be the most tolerant of high temperature over $30^{\circ}C.$, and T. tetrathele of low temperature below $6^{\circ}C.$. In culture density, T. suecica showed the highest growth rate among the among the five species. The cell density of this microalgae attained to $141{\times}10^4$cells/ml at $24^{\circ}C.$ and 30${\textperthousand}$ within 7 days. In chemical composition, crude protein amount was the highest in T. suecica (44.50%), and crude lipid amount it T. sp. (Haeundae, 7.13%). Total essential amino acid amount was the highest in T. sp. (Haeundae, 50.4%) and total polyunsaturated amount in T. sp. (China, 11.7%) The results on growth and chemical composition of five species of Tetraselmis indicated that T. suecica seemed to be the most suitable species for mass culture in Korea.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.349-355
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• 2007

Phylogeny of the species mainly from the genus Amynthas in family Megascolecidae was inferred at the molecular level using ITS regions in rDNA. With 26 species of earthworms from 10 genera in 2 families, a stretch comprising the 3'-end of the 18S rRNA, ITS1, 5.8S rRNA, ITS2, and 5' end of 28S rRNA was amplified by applying the primers ITS-1, ITS-2. Phylogenetic analyses of nucleotide sequences with a help of MP, NJ, and QP yielded 5 groups similarly. Genus Amynthas was separated largely into two groups, Korean and Philippine origins. Species grouped into the 1st were Amynthas jirensis, A. agrestis, A. gucheonensis, A. sopaikensis, A. bubonis, A. multimaculatus, A. koreanus, A. dageletensis, A. heteropodus, A. odaesanensis, Pontoscolex sp., Pheretima sp. 1, and Dendropheretima banahawensis. Amynthas halconensis, A. isarogensis, A. mindrooensis, Pithemera sp. 2, Pithmera sp. 1, and Pleionogaster sp. clustered into one clade forming the 2nd group. Polypheretima sp. 1 and polypheretima. sp. 2 stayed closely together representing a separate monophyletic status, forming the 3rd group, apart from species in other genera. Archipheretima sp. falls into the 4th group. Distinct morphological characteristics from Archipheretima also coinsides with its branching away from others in the previously reported molecular analyses. Similar to Perionyx excavatus that has been selected as an outgroup, Aporrectodea tuberculata also showed a long branch in the phylogram, but it differed from other 24 species included in the analyses. Unlike others, for example, its habitat is very closely related to that of man.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.242-246
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• 1996

High viscous hyaluronic acid complex from Klebsiella sp. L-10 NTG 50 mutant was purified by two-phase extraction system using PEG-K2HP04 and its physicochemical properties were Investigated. Viscosity of the purified hyaluronic acid complex was decreased as temperature and salts concentration were Increased and also showed low viscosity at below pH 5.0 and above pH 11.0. Hardness, cohesiveness and adhesiveness of the purified hyaluronic acid complex were 1, 20kg, 1.91 and 0.62, respectively. Water holding capacity was 6.9ml per gram of the purified hyaluronic acid complex powder.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.374-382
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• 1999

Background: The aim of this study was to investigate etiologic factor, treatment, prognosis of spontaneous pneumothorax (SP). Material and Methods: The medical records of 225 cases of SP experienced at Kyungpook University Hospital from Jan. 1996 to Dec. 1997 were retrospectively analyzed. Results: The patients were 128 primary SP and 97 secondary SP. The mean age was $30{\pm}15.5$ years in primary SP and $51{\pm}7.4$ years in secondary SP. The ratio of male to female was 8:1 in primary SP and 5.5:1 in secondary SP. Smoker was more common in seconday SP (71.1 %) than primary SP (34.4%). About 70% of patients with primary and secondary SP was underweighted. The previous history of SP was present in 28.9% and 25.8% of primary and secondary SP, respectively. The main underlying lung diseases in secondary SP were inactive tuberculosis (68%), active tuberculosis (12.4%) and COPD (11.3%). Tube thoracostomy was performed in 96.8% and 97.9% of primary and secondary SP, respectively. The duration of chest tube insertion was longer in seconday SP ($18.2{\pm}19.59$ days) than primary SP ($7.5{\pm}6.57$ days). The open thoracotomy were performed in 22.7% and 10.3% of primary and secondary SP, respectively. The most com- mon indication of open thoracotomy was recurrence in primary SP and persistent air leak in secondary SP. During following-up of $17{\pm}7.8$ months, the recurrence rate in patients with conservative treatment was 16.5% and 11.8% of primary and secondary SP, respectively. The recurrence was most common within 1 month after discharge. Conclusion: Greater attention and research about SP are necessary for more efficient patient care.

• Journal of Life Science
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• v.22 no.2
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• pp.239-244
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• 2012

The purpose of this paper is to analyze the characteristics and chemical components of biosurfactant produced by Pseudomonas sp. G314. Pseudomonas sp. G314 was isolated from soil samples which were contaminated with oil in Daejon area. As such, it produced quality biosurfactant [23]. One type of biosurfactant was kept in a refrigerator, whereas another type of biosurfactant was kept in room temperature. The surface tension activities were then compared. As a result, the biosurfactant from Pseudomonas sp. G314 that was kept at room temperature was stable for 10 days, showing 26.2 dyne/cm of surface tension activity. This result was found to be similar to that of the refrigerator storage. The surface tension of batch culture was 25 dyne/cm, but the culture in the 5 l fermentor was 27 dyne/cm. Therefore, it can be suggested that the large-scale culture is feasible via the fermentor. Biosurfactant from Pseudomonas sp. G314 was estimated to be a kind of glycolipid because it dissolved in acetone and methanol much better than in benzene and toluene [23]. A spot was detected through the elution of silica gel column and the spread of TLC, and the Rf value was 0.58. This spot has a positive reaction with Bail's reagent and rhodamine 6G. Hence, we can conclude that biosurfactant from Pseudomons sp. G314 was a glycolipid containing carbohydrate and lipid.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.540-546
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• 1999

The purpose of this study was to investigate the antimicrobial effects and characteristics of protamine extracted from spermary of tuna. The result of amino acids analysis showed that the contents of arginine were 46%. It was 10% lower when compared to standard protamine (SP: Asama kasei LTD, Japan). Also, there were significant difference in the contents of proline adn glycine. The average molecular weights of main protein in TP were 13,400 Da, whereas those in SP were 11,300 Da and 2,600 Da. To increase antimicrobial activities of TP, pepsin or trypsin was treated at $37^{\circ}C$. After TP was hydrolyzed with pepsin (pepsin hydrolyzed protamine: PHP) for 4hrs, the average molecular weights of the main protein were 11,300 Da and 3,900 Da, and the antimicrobial activities were significantly increased compared to TP. After TP was hydrolyzed with trypsin (trypsin hydrolyzed protamine: THP) for more than 10 min, the average molecular weights of the main protein were below 2,500 Da. PHP had higher antimicrobial effects on some gram positive bacteria (Staphylococcus aureus, Lactobacillus helveticus, Lactobacillus plantarum) than SP. However, THP had no antimicrobial activities. When TP was hydrolyzed with pepsin (PHP), its antimicrobial activities increased in the same level with those of SP, and this increase might be resulted rather from the changes of molecular weights of the main protein than from the contents of arginine in protamine.

• Journal of Life Science
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• v.16 no.4
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• pp.555-560
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• 2006

A bacterium producing novel lipolytic enzyme was isolated from house sewage and identified as Acinetobacter sp. BD5 based on physiological characterization and 16S rDNA sequencing. The lipolytic activity of Acinetobacter sp. BD5 was tested using an EL agar medium and CE agar medium supplemented with 1% tributyrin and olive oil, respectively. The formation of a clear zone around the colony was detected by agar medium supplemented with 1% tributyrin and olive oil, respectively and Acinetobacter sp. BD5 formed powder-like zone around the colony on LB agar medium containing Tween 20. The quantitative lipolytic activity was determined by using p-NP butyrate as substrate. Acinetobacter sp. BD5 secreted the lipolytic enzyme during exponential growth phase, reaching a maximum amount after 6 hours of incubation. The lipolytic enzyme was found to be optimally active at $60^{\circ}C$ and retained more than 70% at $70-80^{\circ}C$. It displayed a high degree of activity in a pH of 7.0 to 10.6, with an optimal pH of 9.0.