• Journal of the Korean Society of Food Culture
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• v.7 no.4
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• pp.329-338
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• 1992

This study was attempted aimed to prepare of Andong sikhe by pure culture inoculation and to improve storage stability by the addition of stabilizers to the product. Lactobacillus delbreuckii was selected for pure culture inoculation in the fermentation. The effect of stabilizers on the sedimentation, sensory evaluation and viscosity of Sikhe were investigated during the fermentation of traditional Andong Sikhe stored at $4^{\circ}C$ Morphological characteristics of Sikhe were determined by scanning electromicrograpy. Among the stabilizers added to the traditional Andong sikhe Na-alginate was found to be best stabilizers. When the product was evaluated by the sensory panel, the addition of stabilizers up to 0.1% level actually increased the acceptability of the product, while the concentration of more than 0.2% stabilizers affected the acceptability of the negatively. Sikhe added Na-carboxymethyl cellulose and Na-alginate showed highest viscosity on the 2nd day of fermentation, while homogenized Andong sikhe with Carrageenan showed the highest peak in viscosity on the first day of fermentation. Lactic acid bacterial count reached to $3.2{\times}10^8/ml$ after 20 days of storage. The surface and cross section of rice was observed by scanning electron microscope. As the fermentation proceeded holes on the surface increased, and nearly empty cell wall remained at the later stage of fermentation. Use of pure cultured inoculum of L. delbreuckii supported the rapid build up of the lactic acid bacteria and consequently the whole process of the fermentation was shortened. The acceptability and product quality were improved by use of L. delbreuckii inoculum.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.323-328
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• 2006

A bacterium producing the extracellular protease was isolated from insect-eating plant and has been identified as a member of the genus Bacillus based on partial 165 rRNA sequences. In order to develop the medium composition, effects of ingredients including nitrogen sources, carbon source, metal ions and phosphate were examined for protease production of the isolate, SH-8. Soluble starch increased the protease productivity, while glucose repressed it. Yeast extract was effective nitrogen source for enzyme production, but the pretense production of Bacillus sp. SH-8 was reduced by large amount of yeast extract. The calcium was found to induce pretense activity as well as protease productivity. However, cell growth and enzyme production was completely inhibited by divalent ions such as $Zn^{2+}$, $Cu^{2+}$, $Co^{2+}$ and $Mn^{2+}$. The maximum protease productivity was reached 435 unit/ml in the optimized medium consisting of soluble starch (2%), yeast extract (0.3%), $CaCl_2$ (0.3%), $K_2HPO_4$ (0.01%) and $KH_2PO_4$ (0.01%). The pretense activity of culture filtrate was dramatically decreased after incubation for 26 h.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.271-276
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• 2006

Previously we demonstrated that virus-inducible stress protein (VISP) is induced in fish cells by the infection of a fish rhabdovirus. In this paper, we investigated the subcellular localization of the VISP and determined the region of VISP responsible for the subcellular localization. The CHSE-214 cells were stained with monoclonal antibody raised against VISP and observed with confocal microscope to detect the endogenous VISP. The results showed that the VISP localizes to the perinuclear region as spots. A plasmid expressing VISP fused to enhanced green fluorescent protein (EGFP) was constructed. The transient expression of full-length VISP fused to EGFP in CHSE-214 cells confirmed the spot formation of the VISP at perinuclear region. To determine the region responsible for the perinuclear localization of the VISP, we constructed a series of deletion mutants and, by using these deletion mutants, we found that C-terminal region of the VISP (aa 612-710) is essential for the perinuclear distribution of VISP and that this region contained nuclear receptor binding motif (691-TLTSLLL-697). Our results suggest that VISP localizes to the perinuclear region and C-terminal regions are important for this localization. Further studies on the role of the perinuclear localization of VISP in IHNV growth mali reveal the novel mechanism of IHNV pathogenecity.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.251-257
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• 2011

Rice is the most important crop as a model plant for functional genomics of monocotyledons. Rice is usually transformed using Agrobacterium tumefaciens. However, the transformation efficiency using previous method is still low. In this study, we established a new method by modifying the general Agrobacterium protocol especially in the inoculation and co-cultivation step. We directly inoculated Agrobacterium containing a CIPK15 gene under the control of CaMV 35S promoter and NOS terminator in the pCAM1300 vector into the pre-soaked seeds in N6D media for 24 hours. After 7 days of culture at $25^{\circ}C$, calli were formed on seeds cultured on the co-cultivation medium containing an antioxidant compound (1 mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (3 mg/L silver nitrate). We obtained 35 and 22 transgenic plants in rice cultivars, Gopumbyeo and Ilpumbyeo, with increase of transformation efficiency by 30.4% and 22.6%, respectively compared to the general transformation method. The new method in this study would lead to reduction of substantial labor and time to generate transgenic plants.

• Development and Reproduction
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• v.11 no.3
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• pp.195-203
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• 2007

Sex determination and sex differentiation are influenced by genotype in many gonochoristic fish. Cytochrome P450 aromatase (CYP19) is the terminal enzyme in steridogenic pathway that converts androgens into estrogens. In this study, partial fragments of aromatase genes (ovarian aromatase, P450aromA and brain aromatase, P450aromB) were cloned and sequenced in Korean rockfish (Sebastes schlegeli), and gene specific primers were designed based on their sequences. Using these primers, aromatase gene expression during sex differentiation was investigated by RT-PCR. Expression of these aromatase genes were detected both in the head and body parts at 35 dab (days after birth). The number of fish that expressed the aromatase genes decreased at 52 dab, implying down-regulation of these genes. However, these genes were expressed at 59 dab in almost all fish studied here. The expression patterns of both genes are similar throughout the investigated period except for 45 dab where the expression of P450aromB was detected in more fish than that of P450aromA both in the head and body parts. Timing of sex differentiation in this species has been shown to be at around $50{\sim}65$ dab by histological analysis. However, the results from this study suggest that sex differentiation of rockfish may take place $1{\sim}2$ weeks earlier than the period proposed previously. The results also suggest that the mechanism of sex differentiation in viviparous fish may be similar to that in oviparous fish in terms of the importance of aromatase action during the critical period.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.263-270
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• 2015

A bacterial strain producing extracellular mannanases was isolated from soil of chestnut tree farm located in Gongju city of Korea by enrichment culture using Avicel as a carbon source. 16S rDNA sequence of the isolate YB-43 was highly homologous to those of genus Cellulosimicrobium strains with sequence similarities of above 99.6%. Mannanase productivity was significantly increased when the Cellulosimicrobium sp. YB-43 was grown in the presence of locust bean gum (LBG) or konjac. The mannanases were partially purified to be mannanase A (ManA) and mannanase C (ManC) by DEAE-Sepharose column and Q-Sepharose column chromatography from the culture filtrate of Cellulosimicrobium sp. YB-43 grown in LB medium supplemented with 0.7% LBG for 24 h. The partially purified ManA showed the highest activity at $55^{\circ}C$ and pH 6.5, while ManC activity was optimal at $65^{\circ}C$ and pH 7.5. ManA was stable up to $40^{\circ}C$ for 1 h, but ManC activity decreased significantly even after 1 h at $20^{\circ}C$. ManA and ManC showed difference from each other according to their substrate specificities and predominant products resulting from the mannanase hydrolysis for mannooligosaccharides. As a result, Cellulosimicrobium sp. YB-43 was found to produce two different kinds of mannanases.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.110-117
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• 2009

To characterize plant root-associated bacteria in wild plant family Solanaceae, Solanum nigrum L. plants were collected in Dokdo island. Forty four strains of nitrogen-fixing or spore-forming bacteria were isolated from rhizosphere of Solanum nigrum L. plants. Among these, 19 strains were able to produce auxin. Thirteen strains of these produced siderophore as determined by color reaction on CAS-blue plate, 8 strains were able to solubilize phosphate. The 16S rDNA genes of the isolated bacteria were amplified and sequenced. Model plants, pepper and tobacco, were established in order to evaluate the bacterial capacities eliciting growth promotion and induced systemic resistance. The plants treated with strain KUDC1009 were more resistant and capable of growth-promotion than control plants when challenged by either Xanthomonas axonopodis pv. vesicatoria or Erwinia carotovora sub. carotovora strain SCC1. Rhizobacteria isolated from Dokdo island can promote growth of wild type Solanum nigrum L. under much environmental stresses.

• Horticultural Science & Technology
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• v.17 no.1
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• pp.7-10
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• 1999

This study was carried out with the purpose of looking into the transcriptionally regulated genes related to the anther development, characterizing them, and applying their promoters to induce male-sterile plants and restore their fertility. Fifteen anther-specific clones were isolated from the anther cDNA library of Chinese cabbage through the differential screening and sequenced partially at both ends. These partial sequence data showed that cDNA clones BAN52, 84, 101, and 229 are very similar to polygalacturonase, ascorbate oxidase, $H^+-translocating$ ATPase, and pectin esterase genes respectively. However, the other clones have not been matched to any of gene sequences in data bank. In northern dot blot analysis, the transcripts of cDNA clone BAN5, 10, 33, 52, 57, 102, 103, 215, 229 appeared in the flower bud of 2.1 mm in length and their amounts were gradually increased along with the anther development. Transcription of cDNA clone BAN32, 54, 62, 84, 101 began in flower bud of 3.9 mm, which is the late stage in anther development. However, the transcription of BAN87 was very small, but its transcript was detected in all anther developmental stages.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.353-360
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• 2003

For the simple rapid bioassay of organophosphorus and carbamate pesticide residues, a mass-production system of acetycholinesterase (AChE, EC 3.1.1.7, MAChE) using baculovirus and insect cell culture was constructed. The cDNA for AChE was synthesized from Drosophila melanogaster in Halla Mountain, the lipid anchor tail was removed by PCR and was used for the site-directed mutagenesis of three amino acid residues (E107Y, F368L, L408F). The mutated cDNA was inserted into the baculovirus vector and expressed in insect cells. Maximum cell growth and enzyme activity were reached when the cells $(2{\times}10^6\;cell/ml)$ were infected four times at four-day-intervals. His-tag containing MAChE was purified using Ni-NTA column and used for characterization. The activity was maintained under various pHs (3-10) and temperatures $(20-50^{\circ}C)$ under experimental conditions. As an extraction solution for pesticides, methanol is more effective than ethanol. Against major organophosphate and carbamate pesticides, the MAChE showed better sensitivity than AChE and AChE from housefly (Taiwan).

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.262-269
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• 2012

Seasonal differences of the cultivable bacterial communities associated with the marine sponge, Hymeniacidon sinapium, between spring and summer were analyzed through the Amplified Ribosomal DNA Restriction Analysis (ARDRA). For the cultivation of the bacterial isolates, modified Zobell and MA media were used. The 16S rDNA of individual strains were amplified and fragmented by using two restriction enzymes, HaeIII and MspI. As a result, 23 ARDRA types from the spring sponge and 28 types from the summer sponge were obtained. The partial sequencing result of 1 to 3 selected strains from each types showed over 94% similarities with the known species from the public database. The bacterial communities from the sponge, captured on spring, contained 4 phyla: Actinobacteria, Alphaproteobacteria, Gammaproteobacteria, and Firmicutes. There were 5 phyla observed from the bacterial communities associated with the sponge, captured on summer: Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Bacteroidetes. Gammaproteobacteria was predominant group in both spring and summer, accounted for 33.8% of total in spring and 67.4% in summer, showed increase pattern on summer. Because Firmicutes and Actinobacteria participated in 30.2% and 8.3% of the spring sponge while they represented only 6.9% and 0% of the summer sponge, both bacterial groups showed decrease drift on summer. Betaproteobacteria (4.7%) and Bacteroidetes (4.7%) were only observed on the sponge captured on summer. On the sponge, Hymeniacidon sinapium, more diverse bacterial communities were shown on summer than on spring, and even from the same sponge, there were seasonal differences.