• Journal of Life Science
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• v.28 no.9
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• pp.1056-1061
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• 2018

This article reports an agar-degrading marine bacterium and characterizes its agarase. The agar-degrading marine bacterium, KC-1, was isolated from seawater on the shores of Sacheon, in Gyeongnam province, Korea, using Marine Broth 2216 agar medium. To identify the agar-degrading bacterium as Agarivorans sp. KC-1, phylogenetic analysis based on the 16S rRNA gene sequence was used. An extracellular agarase was prepared from a culture medium of Agarivorans sp. KC-1, and used for the characterization of enzyme. The relative activities at 20, 30, 40, 50, 60, and $70^{\circ}C$ were 65, 91, 96, 100, 77, and 35%, respectively. The relative activities at pH 5, 6, 7, and 8 were 93, 100, 87, and 82%, respectively. The extracellular agarase showed maximum activity (254 units/l) at pH 6.0 and $50^{\circ}C$ in 20 mM of Tris-HCl buffer. The agarase activity was maintained at 90% or more until 2 hr exposure at $20^{\circ}C$, $30^{\circ}C$ and $40^{\circ}C$, but it was found that the activity decreased sharply from $60^{\circ}C$. A zymogram analysis showed that Agarivorans sp. KC-1 produced 3 agar-degrading enzymes that had molecular weights of 130, 80, and 69 kDa. A thin layer chromatography analysis suggested that Agarivorans sp. KC-1 produced extracellular ${\beta}$-agarases as it hydrolyzed agarose to produce neoagarooligosaccharides, including neoagarohexaose (21.6%), neoagarotetraose (32.2%), and neoagarobiose (46.2%). These results suggest that Agarivorans sp. KC-1 and its thermotolerant ${\beta}$-agarase would be useful for the production of neoagarooligosaccharides that inhibit bacterial growth and delay starch degradation.

• Korean Journal of Environmental Agriculture
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• v.12 no.1
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• pp.41-49
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• 1993

The Study was conducted to develope the low temperature tolerant methane-producing bacteria(LTTB) and to increase the efficiency of anaerobic fermentation for the treatment of agricultural and livestock wastes at low temperature. The samples were collected from muddy soil, water logged sediment, organic layer and anaerobic sludge at three latitudes, $34.8{\sim}37.4\;^{\circ}N(Korea)$, $41.4\;^{\circ}N(USA)$ and $54.5{\sim}56.9\;^{\circ}N(Canada)$. They were used for determination of the methanogenesis rates for isolation and identification of the LTTB. The methanogenesis rate of smaples at low temperature were higher in the cellulose medium than methanol medium. The methanogenesis rate in the samples of subarctic region were $15{\sim}19$ moles/ml during 30 days at low temperature($8\;^{\circ}C$), whereas not detected in the samples of temperate region. The methanogenesis rate in the enrichment culture of subarctic samples were inhibited by the $40\;{\mu}g/ml$ of streptomycin + vancomycin or ampicillin + oleandomycin which were not effect to the methanogens. An inhabitation of high temperature tolerant methane producing bacteria was identified in the samples of temperate region, whereas that of the LTTB growing at $8{\sim}13^{\circ}C$ was identified in the subarctic region.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.144-152
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• 1993

A bacterium which degrades efficiently synthetic detergents was isolated from the polluted waters, activated sludge of wastewater treatment plants or polluted soil. This bacterium showed considerably higher growth rate in the agar plate containing $2,000{\mu}g/ml$ of synthetic detergents than any other isolated strains, was identified as a Pseudomonas fluorescens or strains similar to it. The strain was named as a Pseudomonas fluorescens S1. Optimum pH and temperature for the growth of the Pseudomonas fluorescens S1 were pH 7.0 and $30^{\circ}C$, respectively. The strain was resistant to streptomycin and gentamycin, but sensitive to kanamycin. The strain was greatly resistant to zinc chloride, lead nitrate and copper sulfate, but unable to grow in the presence of relatively low concentrations of mercury chloride and silver nitrate. This strain utilized benzene, catechol, cyclohexane and xylene as a sole carbon source. The strain was well grown in the medium containing ABS 10,000${\mu}g$/ml. Degradation of ABS was 55% and 60% at 20${\mu}g$/ml and 100${\mu}g$/ml of ABS, respectively. Benzene ring was degraded 45% in 100${\mu}g$/ml of ABS. During the incubation of the strain in the medium containing ABS 100${\mu}g$/ml and COD 10,000${\mu}g$/ml for 4 days, degradation of ABS and COD were reduced to 40${\mu}g$/ml and 3,200${\mu}g$/ml, respectively. Total amino acid content of the Pseudomonas fluorescens S1 grown with 1,000${\mu}g$/ml of ABS was 115mg/g cell, whereas its content was decreased in the bacterium grown without synthetic detergent by 9.4%.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.220-229
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• 2009

Strain improvement and morphology investigation in bioreactor cultures were undertaken in suspended cultures of Phellinus linteus mycelia for mass production of protein-bound polysaccharides(soluble ${\beta}$-D-glucan), a powerful immuno-stimulating agent. Phellineus sp. screened for this research was identified as Phellinus linteues through ITS rDNA sequencing method and blast search, demonstrating 99.7% similarity to other Phellinus linteus strains. Intensive strain improvement program was carried out by obtaining large amounts of protoplasts for the isolation of single cell colonies. Rapid and large screening of high-yielding producers was possible because large numbers of protoplasts ($1{\times}10^5{\sim}10^6\;protoplasts/ml$) formed using the banding filtration method with the cell wall-disrupting enzymes could be regenerated in relatively high regeneration frequency($10^{-2}{\sim}10^{-3}$) in the newly developed regeneration medium. It was demonstrated that the strains showing high performances in the protoplast regeneration and solid growth medium were able to produce 5.8~6.4%(w/w) of ${\beta}$-D-glucan and 13~15 g/L of biomass in stable manners in suspended shake-flask cultures of P. linteus mycelia. In addition, cell mass increase was observed to be the most important in order to enhance ${\beta}$-D-glucan productivity during the course of strain improvement program, since the amount of ${\beta}$-D-glucan extracted from the cell wall of P. linteus mycelia was almost constant on the unit biomass basis. Therefore we fully investigated the fungal cell morphology, generally known as one of the key factors affecting cell growth extent in the bioreactor cultures of mycelial fungal cells. It was found that, in order to obtain as high cell mass as possible in the final production bioreactor cultures, the producing cells should be proliferated in condensed filamentous forms in the growth cultures, and optimum amounts of these filamentous cells should be transferred as active inoculums to the production bioreactor. In this case, ideal morphologies consisting of compacted pellets less than 0.5mm in diameter were successfully induced in the production cultures, resulting in shorter period of lag phase, 1.5 fold higher specific cell growth rate and 3.3 fold increase in the final biomass production as compared to the parallel bioreactor cultures of different morphological forms. It was concluded that not only the high-yielding but also the good morphological characteristics led to the significantly higher biomass production and ${\beta}$-D-glucan productivity in the final production cultures.

• Journal of the Korean Society of School Health
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• v.12 no.2
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• pp.207-215
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• 1999

The objectives of this study are to explain the use of media materials in school health education with other related factors in elementary, middle, and high schools in Korea. The data were collected by questionnaires from June to September in 1998. The number of subjects were 294 school nurses. The PC-SAS program was used for statistical analysis such as percent distribution, chi-squared test, spearman correlation test, and logistic regression. The use of media materials in health education has become extremely common. Unfortunately, much of the early materials were of poor production quality, reflected low levels of interest, and generally did little to enhance health education programming. A recent trend in media materials is a move away from the fact filled production to a more affective, process-oriented approach. There is an obvious need for health educators to use high-quality, polished productions in order to counteract the same levels of quality used by commercial agencies that often promote "unhealthy" lifestyles. Health educators need to be aware of the advantages and disadvantages of the various forms of media. Selecting media materials should be based on more than cost, availability, and personal preference. Selection should be based on the goal of achieving behavioral objectives formulated before the review process begins. The decision to use no media materials rather than something of dubious quality usually be the right decision. Poor-quality, outdated, or boring materials will usually have a detrimental effect on the presentation. Media materials should be viewed as vehicles to enhance learning, not products that will stand in isolation. Process of materials is an essential part of the educational process. The major results were as follows : 1. The elementary schools used the materials more frequently. But the production rate of media materials was not enough. The budget was too small for a wide use of media materials in school health education. These findings suggest that all schools have to increase the budget of health education programs. 2. Computers offer an incredibly diverse set of possibilities for use in health education, ranging from complicated statistical analysis to elementary-school-level health education games. But the use rate of this material was not high. The development of related software is essential. Health educators would be well advised to develop a basic operating knowledge of media equipment. 3. In this study, the most effective materials were films in elementary school and videotapes in middle and high school. Film tends to be a more emotive medium than videotape. The difficulties of media selection involved the small amount of extant educational materials. Media selection is a multifaceted process and should be based on a combination of sound principles. 4. The review of material use following student levels showed that the more the contents were various, the more the use rate was high. 5. Health education videotapes and overhead projectors proved the most plentiful and widest media tools. The information depicted was more likely to be current. As a means to display both text and graphic information, this instructional medium has proven to be both effective and enduring. 6. An analysis of how effective the quality of school nurse and school use of media materials shows a result that is not complete (p=0.1113). But, the budget of health education is a significant variable. The increase of the budget therefore is essential to effective use of media materials. From these results it is recommended that various media materials be developed and be wide used.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.681-692
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• 1996

The present study was conducted to isolate Babesia gibsoni by culture method of the microaerophilous stationary phase(MASP) and analyse the antigenic properties of the parasite by SDS-PAGE and immunoblot. The results obtained were summarized as follows. The protozoan parasite Babesia gibsoni multiplied in canine erythrocytes in RPMI 1640 medium(pH7.0) containing 20 40% normal canine serum under the MASP condition of 5% CO2 and 95% air at $37^{\circ}C$ incubator. The levels of parasitaemia in the erythrocytes were shown more higher by exchanging the medium at 24 hours interval. Under the above condition of MASP, the percentage of parasitized erythrocytes(PPE) after incubation for 8 days increased about 14 times more than that in the initiation of the 1% infected canine erythrocyte culture. The parasites were purely isolated from the MASP culture of red blood cells collected from dogs infected with Babesia gibsoni naturally or artificially. Among the total of 36 canine(Pit-bullterier) blood samples the parasites were isolated from 17 cases(47.2%) in the MASP culture while the parasites were detected from 20 cases(56%) and 12 cases(33.3%), respectively, by indirect fluorescent antibody(IFA) test and direct light microscopy(DLM). On the other hand, Babesia gibsoni was isolated by MASP culture from 15 cases(75%) and 11 cases(92%) of positive cases of IFA and DLM, respectively. In the analysis of the erythrocytic merozoite(AEOM) antigen derived from infected dog approximately 11 antigenic bands in molecular weight of 130, 120, 97.4, 92, 80, 52, 50, 42, 36, 30 and 29 KDa were observed on SDS-PAGE. Antigenic bands in the endoerythrocytic merozoite(CEOM) antigen derived from infected erythrocyte (sediment) in MASP culture were much similar to those of AEOM bands. In the exoerythrocytic merozoite(CEEM) antigen derived from supernatant of the infected erythrocyte culture approximately 20 antigenic bands were observed and the molecular weight of the major bands among these were 140, 120, 114, 105, 96, 93, 92, 80, 60, 52, 50, 38, 36, 30, 24, 18.5 and 16 KDa. In the protein patterns of AEOM and CEOM antigen by immunoblot 15 bands were observed and these patterns were much similar between each other. The molecular weight of the major bands in the both antigens were 130, 120, 80, 60, 52, 50, 42, 30, 29, 18.5 and 16 KDa. Approximately 21 bands were observed in CEEM antigen and the molecular weight of the major bands were 140, 120, 96, 92, 85, 80, 76, 60, 52, 50, 37, 30, 24, 16 and 15 KDa. The specific antigenic bands in the artificially infected dogs were firstly observed at 3 weeks afrer inoculation of infected blood and these antigenic bands were maintained up to 18 months after inoculation. In the immunoblot of the sera of the splenectomized dogs the specific antigenic bands with the molecular weight of 93 KDa and 52 KDa, respectively, were observed weakly comparing to those of non-splenectomized dog. In immunoblot of the sera collected from the naturally infected dogs the antigenic bands were observed as same as those of artificially infected dogs while antigenic band of 29 KDa in some individual dog showed strongly. In comparison of immunoblot of the sera collected from dogs non-treated and treated with diminazene aceturate(7mg/kg, IM) after artificial infection no differences of antigenic bands were observed. In analysis of antigenic bands by digoxigenin glycan/protein double labeling, antigenic bands in the molecular weight of 106, 60 58, 36, 30 and 29 KDa were determined as glycoproteins.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.528-533
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• 2009

In the current study, the mesenchymal stem cells (MSCs) isolated and propagated from the human umbilical cord blood (UCB) were tested for their capabilities of differentiation into chondrocytes in vitro. The mesenchymal progenitor cells (MPCs) collected from UCB were cultured in a low glucose DMEM medium with 10% FBS, L-glutamine and antibiotics. The human MSC colonies were positively stained by PAS reaction. When the immunophenotypes of surface antigens on the MSCs were analyzed by fluorescence-activated cell sorter (FACS) analysis, these cells expressed positively MSC-related antigens of CD 29, CD44, CD 90 and CD105, whereas they did not express antigens of CD14, CD31, CD34, CD45, CD133 and HLA-DR. Following induction these MSCs into chondrocytes in the chondrogenic differentiation medium for 3 weeks or more, the cells were stained positively with safranin O. We clearly confirmed that human MSCs were successfully differentiated into chondrocytes by RT-PCR and immunofluorescent stain of type-II collagen protein. These data also indicate that the isolation, proliferation and differentiation of the hUCB-derived MSCs in vitro can be used for elucidating the mechanisms involved in chondrogenesis. Moreover this differentiation technique can be applied to developing cell-based tissue regeneration or repair damaged tissues.

• Journal of Life Science
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• v.24 no.9
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• pp.988-994
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• 2014

The effluents of chemical and petroleum industries often contain non-biodegradable aromatic compounds, with phenol being one of the major organic pollutants present among a wide variety of highly toxic organic chemicals. Phenol is toxic upon ingestion, contact, or inhalation, and it is lethal to fish even at concentrations as low as 0.005 ppm. Phenol biodegradation has been studied in detail using bacterial strains. However, these microorganisms suffer from substrate inhibition at high concentrations of phenol, whereby growth is inhibited. A phenol-degrading bacterium, P21, was isolated from oil-contaminated soil. The phenotypic characteristics and a phylogenetic analysis indicated the close relationship of strain P21 to Rhodococcus pyridinovorans. Phenol biodegradation by strain P21 was studied under shaking condition. The optimal conditions for phenol biodegradation by strain P21 were 0.09% $KNO_3$, 0.1% $K_2HPO_4$, 0.3% $NaH_2PO_4$, 0.015% $MgSO_4{\cdot}7H_2O$, 0.001% $FeSO_4{\cdot}7H_2O$, initial pH 9, and $20-30^{\circ}C$, respectively. When 1,000 ppm of phenol was added to the optimal medium, the strain P21 completely degraded it within two days. Rhodococcus pyridinovorans P21 could grow in up to 1,500 ppm of phenol as the sole carbon source in a batch culture, but it could not grow in a medium containing above 2,000 ppm. Moreover, strain P21 could utilize toxic compounds, such as toluene, xylene, and hexane, as a sole carbon source. However, no growth was detected on chloroform.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.678-686
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• 2007

Human mesenchymal stem cells(hMSC), that have been reported to be present in bone marrow, adipose tissues, dermis, muscles and peripheral blood, have the potential to differentiate along different lineages including those forming bone, cartilage, fat, muscle and neuron. Therefore, hMSC are attractive candidates for cell and gene therapy. The optimal conditions for hMSC expansion require medium supplemented with fetal bovine serum(FBS). Some forms of cell therapy will involve multiple doses, raising a concern over immunological reactions caused by medium-derived FBS proteins. Previously, we have shown that hADSC can be cultured in human serum(HS) during their isolation and expansion, and that they maintain their proliferative capacity and ability for multilineage differentiation and promote engraftment of peripheral blood-derived CD34 cells mobilized from bone marrow in NOD/SCID mice. In this study we determined whether hADSC grown in HS maintain surface markers expression similar with cells grown in FBS during culture expansion and compared gene expression profile by Affymetrix microarray. Flow cytometry analysis showed that HLA-DR, CD117, CD29 and CD44 expression in HS-cultured hADSC during culture expansion were similar with that in FBS-cultured cells. However, the gene expression profile in HS-cultured hADSC was significantly different from that in FBS-cultured cells. Therefore, these data indicated that HS-cultured hADSC should be used in vivo animal study of hADSC transplantation for direct extrapolation of preclinical data into clinical application.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.384-397
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• 2018

The aim of this study is to screen the strains of Bacillus spp. possessing safety, probiotic activity, and so on, which can be utilized as probiotic resource for using the feed and supplement food of companion animal. About 300 isolates were isolated from traditional Korean sauces, four isolates that did not have or produce the six kinds of B. cereus type vomiting and diarrhea toxin genes, ${\beta}$-hemolytic, and three kinds of carcinogenic enzymes were selected. Antibiotic gene retention, cell surface hydrophobicity, antibiotic sensitivity, and glucose utilization were analyzed for four isolates, and finally SRCM 100731 was selected. SRCM 100731 was named as Bacillus amyloliquefaciens SRCM 100731 16S rRNA sequencing analysis, and carried out optimization of cell growth for industrial applications such as pet food and feed. The effects of 14 different components on cell growth were investigated and three significant positive factors, molasses, sodium chloride, and potassium chloride were selected as the main factors based on a Plackett-Burman design. In order to find out optimal concentration on each constituent, we carried out central composite design. The predicted optimized concentrations were 7% molasses, 1.1% sodium chloride, 0.5% potassium chloride. Finally, an overall about 7-fold increase in dry cell weight yield ($12.6625{\pm}0.0658g/L$) was achieved using the optimized medium compared with the non-optimized medium ($1.8273{\pm}0.0214g/L$). This research is expected to be highly utilized in the growing pet industry by establishing optimal cultivation conditions for industrial application as well as screening Bacillus amyloliquefaciens SRCM 100731 as probiotic resource for companion animal.