• Journal of Life Science
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• v.23 no.9
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• pp.1133-1139
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• 2013

During the collection of boar semen, bacterial contamination usually occurs. The contamination has deleterious effects both on semen quality and on sow fertility. The majority of contaminants are gram-negative bacteria, especially Serratia marcescens. In this study, we developed a PCR assay for the identification of S. marcescens targeting the luxS gene (GenBank no. EF164926). S. marcescens yielded a specific 306 bp PCR product. However, no amplification was observed in the other strains tested. The detection limit of PCR was $50pg/{\mu}l$ of template DNA of S. marcescens. The antimicrobial susceptibility patterns of S. marcescens isolated from boar semen were tested using the disk diffusion method. Gentamicin, ceftiofur, florfenicol, and neomycin showed high sensitivity in this test. The minimum inhibitory concentration (MIC) was also determined by the broth microdilution method. The $MIC_{90}$ values of ceftiofur, enrofloxacin, gentamicin, and neomycin were 8, 8, 8, and $16{\mu}g/ml$, respectively. These results indicate that PCR amplification of the luxS gene is a reliable and effective method for the identification of S. marcescens and that ceftiofur, enrofloxacin, gentamicin, and neomycin are effective semen extenders for controlling S. marcescens.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.82-88
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• 2017

Transgenic lily plants have been obtained after particle bombardment, using PDS-1000/He system and scale explants of lilies, followed by PPT (D-L-phosphinothricin) selection. In this study, scales of the lily plants cv. 'red flame' were bombarded with a plasmid containing the bar gene as a selectable marker, and the AtSIZ gene as a gene of interest, showing salt tolerance and drought tolerance respectively, and both being driven by the CaMV 35S promoter. For optimization of a protocol, factors which optimized and showed a high transformation efficiency under following conditions, were considered: a bombardment pressure of 1100 psi, a target distance of 6 cm and $1.0{\mu}m$ of gold particle, and 24-h pre-culture and post-culture on MS medium containing 0.2 M sorbitol and 0.2 M mannitol as osmoticum agents. After bombardment, all the bombarded scales of lily were transferred to MS medium without selective agents, for a week. Subsequently, these bombarded scales were transferred to a selection MS medium containing 10 mg/l PPT, and incubated for a month for further selection, after which they were cultured for another 4-8 weeks with a 4-week subculture regime on the same selection medium. After transferring into hormone-free MS medium, the PPT-resistant scales with shoots were successfully rooted and regenerated into plantlets. PCR analysis revealed that the surviving putatively transformed plantlets indicated the presence of both the bar gene and the AtSIZ gene. In conclusion, when 100 scales of lily cv. Red flame are bombarded, this study produced approximately 17-18 transgenic plantlets with an optimized bombardment protocol. The protocol described here can contribute to the breeding program of lilies.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.1
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• pp.71-78
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• 2005

This study was performed to obtain the basic data on current situations and challengeable aspects of vermicomposting industries in Korea and to develope foodwaste treatment technology using earthworm. Pre-treatment process of food waste consists of cleaning, grinding, mixing and others, and salinity of food waste was 0.7% on average, thus not suitable for feed of worms. When applying wash water and going through the cleaning process, however, salinity was dropped to 0.38%, indicating that cleaning process applying wash water is necessary to control the proper salinity for growth of worms. In the food waste processing experiment applying worms, it has been presented that smaller particles induce higher processing efficiency. As a result, food waste processing by worms is possible through maintaining the suitable environment for survival of worms from input process to generation of cast. Cast generated after processing food waste was proved to be most suitable for product standard of compost thus cast is presented to be recycled after processing the food waste applying the worms.

• Journal of Life Science
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• v.13 no.1
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• pp.118-127
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• 2003

$\rho$-Fluorophenylalanine (FPA), a phenylalanine analog, is able to induce apoptotic cell death of human acute leukemia Jurkat T cells. To better understand the mechanism by which FPA induces apoptotic cell death, the effect of ectopic expression of antiapoptotic proteins, Bcl-2 and Bcl-xL, on FPA-induced apoptosis was investigated by employing lurkat T cells transfected with Bcl-2 gene (JT/Bcl-2) or Bcl-xL gene (1/Bcl-xL) and Jurkat T cells transfected with vector (JT/Neo or J/Neo). When Jurkat T cells, JT/Neo or J/Neo, were exposed to FPA at concentrations ranging from 0.63 to 5.0 mM, the cell viability determined by MTT assay declined in a dose-dependent manner. In addition, apoptotic DNA fragmentation along with several apoptotic events such as caspase-8 activation, Bid cleavage, mitochondrial cytochrome c release, caspase-9 activation, caspase-3 activation, and degradation of PARP was induced. However, the FPA-induced cytotoxic effect, activation of caspase-8, and cleavage of Bid were significantly abrogated by ectopic expression of Bcl-2 or Bcl-xL. At the same time, there was marked reduction in the level of cytochrome c release from mitorhondria, caspase-9 activation, caspase-3 activation, and degradation of PARP. These results indicate that caspase-8 activation, Bid cleavage, and mitochondrial cytochrome c release with subsequent activation of the caspase cascade are negatively regulated by Bcl-2 or Bcl-xL, and are thus required for FPA-induced apoptosis in Jurkat T cells

• Applied Biological Chemistry
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• v.50 no.4
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• pp.281-286
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• 2007

The effects of green tea powder (GTP) on kimchi quality were evaluated by investigating acid production, growth of lactic acid bacteria, sensory properties, and several volatile odor components of GTP-added kimchi. The concentrations of GTE added to kimchi were 0.2, 0.4, 0.6 and 1.2% (w/w) of salted Chinese cabbage. The pH of kimchi with higher amounts of added GTP increased with ripening. The acidity of unripened kimchi or kimchi ripened for one day generally increased with the addition of GTP, while that of kimchi ripened for two or three days generally decreased with the addition of GTP. Addition of GTP had no significant effect on the lactic acid bacterial count of kimchi. Scores of overall acceptability, taste and odor of 0.2 or 0.4% GTP-added kimchi were higher than those of other samples, whereas scores of color decreased with increasing amount of GTP added to kimchi. Texture of kimchi added with higher amounts of GTP and ripened for two or three days resulted in lower score than the reference sample. Diallyl sulfide and methyl trisulfide were newly produced with the ripening of kimchi, and the amounts of some volatile odor components in kimchi were changed during ripening.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.197-205
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• 2015

This study was performed to identify the effect of fertilizer application and planting method on growth and yield of 'Seolhyang' strawberry during seedling raising. According to the concentration of fertilizer applied, the height of daughter plants was the highest at an EC of $0.8dS{\cdot}m^{-1}$. Leaf number and crown diameter were greatest at an EC of $0.6-0.8dS{\cdot}m^{-1}$. In the first measurement, root number was highest in non-fertilizer application, while root weight was heaviest in non-fertilizer application and EC $0.4dS{\cdot}m^{-1}$. The higher the concentration of fertilizer applied as culture media, the lower the growth rate. Thirty days after planting on the main field, plant height and number of new leaf were highest at an EC of $0.8dS{\cdot}m^{-1}$. However, no significant difference was found in leaf length and width and chlorophyll content according to fertilizer application. Marketable yield of 25 g or higher was greatest in EC $0.6dS{\cdot}m^{-1}$. In contrast, no significance was found in total marketable yield at an EC of $0.4-0.8dS{\cdot}m^{-1}$. Aconsistent pattern was exhibited in the growth of 1-5 harvesting flower clusters according to planting method. The length of leaf and flower cluster was short and chlorophyll content was low, when bed soil was removed 100% in harvesting of the first flower cluster. In all treatment, leaf length was shortened until harvesting of the second and third flower cluster, but rapidly lengthened in harvesting of the third and fourth flower clusters. Moreover, the length of flower cluster had a increasing tendency from harvesting of the third flower cluster. However, chlorophyll content was reduced continuously until harvesting of the fifth flower cluster, and was lowest in harvesting of the fourth flower cluster without removal of bed soil. Total yield was greatest in treatment of crown removal in bed soil between November and May. Late marketable yield between March and May was highest in treatment of 100% bed soil removal, followed by treatment of crown removal. Marketable yield of 25 g or higher was greatest in treatment of crown removal between December and February, while greatest in treatment of 100% bed soil removal between March and May.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.325-336
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• 1992

The successional status and potential natural vegetation were examined in a mixed broadleaved-Abies forest located at Mt, Odae National Park. The examination was based on the subsequent process of generation replacement by understory saplings for the dominant canopy trees within 88 $5m{\times}50m$ belt transects. The transition matrix model, which was modified from mathematical theory of Markov chain, was employed to analyze the successional status of the study forest. The model suggests that the study forest is still seral, and it is considered to be more than 700 years away from the steady state or climax in terms of species composition. The simulations predict a remarkable decrease in the proportion of species composition of the present dominant Quercus mongolica and Tilia amurensi.s from current 28% and 13% to less than 3% and 5%, respectively, at the steady state. On the contrary, the proportions of Abies holophylla, Acer pseudo-sieboldianum, Carpinus cordata, and Pinus koraiensis will increase at the steady state. The ratio of mixture between deciduous and coniferous trees will be gradually changed from current 6.5 : 3.5 to 5.0 : 5.0 at equilibrium. Discussion for the problems of Quercus mongolica in successional status noted that the species behaved as a mid-successional dominant, not a climax species in the study forest. The hypothesis and sensitivity of the transition matrix model were also discussed to evaluate the applicability to the real situation. The overall results indicated that the present dynamics of the forest must reflect the seral state due to previous disturbance mainly by hyman related interference.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.232-237
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• 2001

This study was conducted to clarify the effects of physical stimulation to the rice plant by free-ranging ducks (Chinese native ducks) on growth, lodging resistance and yield of the rice plants in a rice-duck farming system. Two paddy fields were used for this experiment, one exposed to physical stimulation (PS) and the other with no physical stimulation (NPS). Fifteen days after ducks were introduced into the paddy plot, rice plants in the PS field were significantly (P<0.05) shorter than those in the NPS field. Measurements of lodging characteristics showed that, the 3rd internode was significantly (P<0.05) shorter in the PS treatment than in the NPS treatment, but neither the 4th internode length nor the center of gravity of the rice plants differed between treatments. The breaking strength of $N_4$ in PS rice was significantly (P<0.05) higher than in NPS rice, however the bending moment and the lodging index of $N_3$ (distance between fulcra - 5 cm) was significantly (P<0.05) lower in PS than in NPS. The number of panicles per $m^2$ was significantly (P<0.05) greater in PS rice than in NPS, but there was no such difference in spikelet number per panicle, percentage of ripened grain or weight per 1000 kernels. Paddy rice yield per $m^2$ in the PS treatment was significantly (P<0.05) higher than that in the NPS treatment.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.433-440
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• 2011

In head lettuce seedlings, NaCl stress was treated with hydroponic culture containing 0, 50, or with 100 mM NaCl in the seedling grown up to two leaf stages. Our focus was on the effect of NaCl on fresh and dry weights, antioxidant materials, and inorganic ion level. Fresh and dry weights of head lettuce seedlings increased with the increase in salinity while the optimal growth occured at 50 mM NaCl. The chlorophyll a (Chl a), total Chl and Chl a/b ratio increased 6 days after treatment with 100 mM NaCI. However, the Chl b content decreased. Total glutathione increased only in the root of head lettuce seedlings, whereas significant increase of total arcorbate content was observed in both shoot and root after the treatment with 100 mM NaCl. In addition, the NaCl treatment resulted in the decreased level of spermidine content, and a increased spermine content. Furthermore, $Na^+$ content in shoot and root increased significantly while $K^+$, $Ca^{2+}$, and $Mg^{2+}$ content decreased. The alteration of inorganic ion level after treatment with NaCl caused the reduction of $K^+/Na^+$, $Ca^{2+}/Na^+$, and $Mg^{2+}/Na^+$ ratio with the increase of NaCl concentration. Taken together, these findings indicate that the treatment of NaCl causes the induction of oxidative stress, and results in the alteration of metabolic mechanism in head lettuce seedlings.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.39-43
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• 2011

A new cultivar "Dan Bi" of Pleurotus eryngii was developed by the method of mono-mono crossing between monokaryotic strains derived from KNR2312 and KNR2596. The parental strains, KNR2312 and KNR2596, are characterized by the property of high quality and a small number of primordia formation, respectively. The optimum temperature of mycelial growth was 25 and that of fruiting body development was $15{\sim}16^{\circ}C$. The period of harvesting including primordia formation was 0.7~1.3 days later than that of control strain Knneutari No. 3 in the culling cultivation. The color of pileus and stipe surface was neutral-brown and pure white, respectively. The shape of pileus was dome and has a scale like as cobweb. The yield was $93{\pm}9.7$ g per 850 cc of plastic bottle. Analysis of the genetic characteristics of the new commercial variety "Dan Bi" showed a different profile as that of the control strain, Knneutari No. 3, when RAPD (Random Amplified Polymorphic DNA) primer #8005 was used. This new variety "Dan Bi" of Pleurotus eryngii is characterized by a small number of primordia formation after scratching.