• Journal of agriculture & life science
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• v.44 no.3
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• pp.23-30
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• 2010

The optimal growth condition of in vitro stem cutting of Dendrobium nobile 'Hamana Lake Dream' ${\times}$ 'No. 55' was investigated. Among various media and their concentrations, MS media had better effect on the growth of micro stem cutting than Hyponex media in all concentration levels except stem length. The activated charcoal concentration in MS media showed different effects on number of stem and root, leaf length, and fresh weight: the most effective in the range of 0.1 to 1.0 g/L and barely effective above 2.0 g/L. Addition of agar 5 g/L, sucrose at 40 g/L, and peptone at 1 g/L to MS media increased significantly stem length, leaf width, and fresh weight, internode length and number of roots, and the number of stem and leaves. On the other hand, addition of gelite with any concentration had no effect on the growth of micro stem cutting compare to that of control. The optimal temperature for growth of micro stem cutting was $28^{\circ}C$. Under the same temperature, MS medium was better than Hyponex medium for the growth of stem. In addition, sucrose at 40 g/L was the most effective on growth at $28^{\circ}C$.

• KSBB Journal
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• v.22 no.4
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• pp.239-243
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• 2007

A method of forming agar microcapsule with fibroin coating was developed in this report. The capsules were prepared from a W/O emulsion of hot agar in mineral oil and were subsequently coated by fibroin. The capsules were harvested as precipitated aggregates, which can be dispersed in an aqueous media. The diameter of the microcapsule was less than $10{\mu}m$ by microscopic observation and 90% of them were between $1.32{\mu}m\;and\;6.0{\mu}m$. The structure of the aggregates and their dispersed microspheres were investigated by scanning electron microscope. Confocal microscopy was applied to visualize the core-shell structure of the agar microcapsule with fibroin coating. Thermogravimetric analysis (TGA) measured their composition to be agar 51.2%, fibroin 13.8%, Span 80 1.4% by weight.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.156-162
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• 2016

In this study, we isolated a new agar-degrading marine bacterium and characterized its agarase. An agardegrading marine bacterium SH-1 was isolated from seawater, collected from the seashore of Namhae in Gyeongnam province, Korea, and cultured in marine agar 2216 media. It was identified as Maribacter. sp. SH-1 by phylogenetic analyses, based on 16S rRNA gene sequence. The extracellular agarase was extracted from culture media of Maribacter sp. SH-1 and characterized. Its relative activities were 56, 62, 94, 100, and 8% at 20, 30, 40, 50, and 60℃, respectively, whereas 15, 100, 60, and 21% relative activities were observed at pH 5, 6, 7, and 8, respectively. Its extracellular agarase exhibited maximum activity (231 units/l) at pH 6.0 and 50℃, in 20 mM Tris-HCl buffer. Therefore, this agarase would be applicable as it showed the maximum activity at the temperature at which the agar is in a sol state. Furthermore, the agarase activities remained over 90% at 20, 30, and 40℃ after 0.5 h exposure at these temperatures. Thin layer chromatography analysis suggested that Maribacter sp. SH-1 produces extracellular β-agarase, as it hydrolyzes agarose to produce neoagarooligosaccharides, such as neoagarohexaose (34.8%), neoagarotetraose (52.2%), and neoagarobiose (13.0%). Maribacter sp. SH-1 and its β-agarase would be useful for the production of neoagarooligosaccharides, which shows functional properties, like skin moisturizing, skin whitening, inhibition of bacterial growth, and delay in starch degradation.

• The Korean Journal of Mycology
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• v.46 no.2
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• pp.145-160
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• 2018

Members of Chlorociboria are soft-rot ascomycetes that produce blue-green pigment. We investigated the growth characteristics of two Korean species of Chlorociboria, eight strains of Chlorociboria aeruginascens and Chlorociboria poutoensis, under various culture conditions (solid media, temperature, pH) and screened them for extracellular enzyme activity. Although the growth rate was slow, all tested strains of Chlorociboria spp. grew well on potato dextrose agar (PDA; 16.3~42.6 mm after 60 days) or Sabouraud dextrose agar (SDA), but not on malt extract agar (MEA). Compared with C. aeruginascens strains, C. poutoensis strains exhibited higher expression of blue-green pigments on both PDA and SDA media. The optimal temperature for mycelial growth was $20{\sim}25^{\circ}C$, and mycelial growth was lower at $30^{\circ}C$ than at $10^{\circ}C$. All strains tended to have increased mycelial growth as the incubation temperature increased in the range of 10 to $20^{\circ}C$. The optimal pH of potato dextrose broth (PDB) for mycelial growth varied according to the strain under static culture conditions. Maximum biomass production was obtained at pH 6.0 for NIFoS 579 ($114.3{\pm}5.1mg/60days$), but it maintained a stable pigment expression under a broad pH spectrum. The activities of both cellulase and laccase were observed in all tested strains of Chlorociboria spp. Enzyme activities of NIFoS 579 were remarkably higher than those of the other strains. From these results, we suggest that C. poutoensis NIFoS 579 is a potential candidate for use as a source of natural blue-green dye.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.37-41
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• 1988

The present work deals with the effect of agar and auxins concentrations on vitrification in tissue culture of Gypsophila paniculata L. cv. 'Bristol Fairy' in vitro. The results were summarized as follows. 1. Plant growth, that is, plant height, fresh weight and branching were decreased as increasing agar concentration. On the other hand, addition effect of IAA 1.0mg/l+NAA 0.5mg/l and IAA 2.0mg/l+NAA 1.0mg/l on the plant height were increased strikingly. 2. Addition effect of auxins on the days to rooting were little. And the root development showed same tendency as plant growth. 3. The rate of non-vitrified plants were gradually increased as rising agar concentration. But the addition of agar 1.5g/l in the medium resulted in poor growth. 4. From these results, it was found that following media were the most effective for increasing of non-vitrified and good plant growth in Gypsophila paniculata L. tissue culture.

• The Korean Journal of Mycology
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• v.5 no.2
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• pp.21-23
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• 1977

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.115-125
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• 2000

Three major hospitals with over 500 beds located in and near Seoul were surveyed for airbone microorganisms from February 1, 1998 to February 18, 1998. The purpose of the study was to identify and quantify microbiological organisms circulating in the air of three different areas in the hospitals. For the study, a RCS air sampler was utilized equipped with two different collection media, the agar strip GK-A for bacteria and the agar strip HS for fungi. The areas investigated were the intensive care unit (ICU) in the Department of internal medicine, the Newborns room in the Department of Obstetrics, and the microbiology laboratory. The results were as follows; 1. The average numbers of general microbiological particles collected on the agar strip GK-A media were $205CFU/m^3$, $232CFU/m^3$, and $128CFU/m^3$ in each hospitals. The highest concentration of $387CFU/m^3$ was found in the ICU of A hospital at 15:00 during the day. Further analysis of the collected bioaerosols by gram staining, revealed that there were gram positive cocci (89.5%), gram positive bacilli (7.2%), gram negative bacilli (2.8%), and fungi (0.5%), in descending order of frequency. 2. Ten different genes were identified from the agar strip GK-A. The most frequently identified organisms were: the Coagulase negative staphylococcus (55.0%), Micrococcus (21.4%), Enterococcus species(10.4%), and Bacillus species (7.2%). A series of antibiotics susceptibility test were conducted against the aforementioned four(4) organisms. Ninety percent of coagulase negative stapylococcus were sensitive to Penicillins. Pathogenic microbes isolated include: Staphylococcus aureus, Acinetobacter species, Klebsiella pneumonia, Klebsiella oxytoca, and Pseudomonas aeroginosa. 3 Although 56.8% of the microorganisms grown on the strip HS media for fungi could not be identified, some of them were successfully identified. The most frequently found fungi were Aspergillus (35.3%), Yeast or Molds (6.2%), and Penicillium (0.7%). Based on the results obtained from the study, it was concluded that some areas in the hospitals had abnormally high bioaerosol concentrations which could be attributed to human activity. Therefore, it is recommended that periodic assessments of indoor bioaerosols aiming to identify the possible sources should be conducted in order to maintain clean indoor environment in the hospitals.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.219-223
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• 1991

Effects of media and low temperature on germination of weeds were examined to get basic information for establishing weed control methods. Soil and agar(0.4%) was good media for germination of weeds at laboratory. Germination was improved by placing weed seeds at 5$^{\circ}C$ low temperature for 10-20 days. Germination was improved by storing weed seeds in water absorbed gauge and in vinylbag at 5$^{\circ}C$ low temperature for 30-40 days. Germination was increased by burial of weed seeds at 10cm of soil depth for 30-60 days.

• KSBB Journal
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• v.13 no.2
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• pp.214-219
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• 1998

Polymerase chain reaction(PCR) was conducted to obtain the gene encoding glucose oxidase(GOD) from Aspergillus niger(ATCC 2110) and the DNA sequence determined was coincided with published GOD sequence from A. niger. Recombinant transforming vector containing GOD and hygromycin B(hyg.B) resistant gene(hph) was constructed and used for further transformation of A. niger ATCC 2110. Selectivity of hyg.B against A. niger differed depending on which media were used i.e., nutrient-rich media such as potato dextrose agar(PDA) and complete medium(CM) showed only 50% growth inhibition at 400 $\mu$m ml$^-1$ of hyg.B while the minimal media inhibited mycelial growth completely at 200 $\mu$m ml$^-1$ of hyg.B. Twenty to sixty putative transformants were isolated from the hyg.B-containing minimal top agar, transferred successively onto alternating selective and nonselective media for a mitotic stability of hyg.B resistance and, then, single-spored. Among the stable transformants, the transformant(GOD1-6) grown by flask culture showed the considerable increase of extracellular GOD activity, which was estimated to the degree of 50% - 100% comparing to that of wild type. Transformation of tGOD1-6 was resulted from integration of the vectors into heterologous as well as homologous regions of the A. niger genome. Southern blot analysis revealed that there were two independent integrations of vector into fungal genome and one into the GOD gene due to homologous recombination. In addition, GOD activity and sodium gluconate production when tGOD1-6 was fed-batch fermented were enhanced 11 fold and 2.25 fold, respectively, compared to that of the wild type.

• Journal of odor and indoor environment
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• v.16 no.1
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• pp.47-53
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• 2017

Mold is one of the important bio-aerosols affecting human health in the indoor environment. To manage mold contamination, it is necessary to use an appropriate method for its detection and enumeration. Recently, the impaction method of ISO 16000-18 has been established as one of methods to detect and enumerate molds in air. To investigate the general use of the impaction method for mold detection in domestic indoor environments, the suitability of the method was assessed using different antibiotics, media and air samplers. All of the three antibiotics tested - ampicillin, chloramphenicol and streptomycin - showed inhibitory effects on bacterial colony formation on MEA and DG-18 media, without inhibiting mold growth. Of these three antibiotics, ampicillin was the most effective. There was no statistical difference between MEA and DG-18 media in the measurement of mold concentration. The formation of discriminative colony morphology was more apparent in DG-18 media. No significant difference in the measurement of mold concentration was found between Andersen samplers and MAS-100NT samplers, which are two major samplers introduced in Korea.