• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.2
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• pp.267-274
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• 1993

This experiment was carried out to determine the effect of mixture ratios of worm cast and soil on the growth orchardgrass seedlings, and estimate the adequate mixture ratio of worm cast for plant growth media. Mixture ratios of worm cast and soil were 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100, respectively. The results were summarized as follows; 1. The value of dry weight of shoot(SW), dry weight of root(RW), number of tillers per plant(NT) and biological yield(BY) were the highest in the mixture with 60% of worm cast. Particularly, the dry weight distribution to root in 20%-60% mixture ratios of worm cast were higher than those grown in 80%-100% mixture ratios of worm cast, it may due to the enhancement of root growth by adquate worm cast mix. 2. The orchardgrass seedlings in the 60% mixture ratio of worm cast grown in favourable soil conditions compared to those grown in other mixtrure ratios of worm cast and soil without worm cast. The soil analysis data showed that 60% mixture ratio of worm cast contained pH 6.16, 13.84% of organic matter, 0.84% of total nitrogen, 1,413.9ppm of available phosphorus and 16.7me／100g of cation exchange capacity, respectively. 3. Biological yield(BY) indicated positive significant correlation with the dry weights of shoot(SW) and root(RW). And, the dry weight of shoot(SW) had positive correlation with the number of tiller per plant(NT) and dry weight of tiller(WT).

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1500-1509
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• 2020

Drought is a major abiotic factor and has drastically reduced crop yield globally, thus damaging the agricultural industry. Drought stress decreases crop productivity by negatively affecting crop morphological, physiological, and biochemical factors. The use of drought tolerant bacteria improves agricultural productivity by counteracting the negative effects of drought stress on crops. In this study, we isolated bacteria from the rhizosphere of broccoli field located in Daehaw-myeon, Republic of Korea. Sixty bacterial isolates were screened for their growth-promoting capacity, in vitro abscisic acid (ABA), and sugar production activities. Among these, bacterial isolates YNA59 was selected based on their plant growth-promoting bacteria traits, ABA, and sugar production activities. Isolate YNA59 highly tolerated oxidative stress, including hydrogen peroxide (H₂O₂) and produces superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities in the culture broth. YNA59 treatment on broccoli significantly enhanced plant growth attributes, chlorophyll content, and moisture content under drought stress conditions. Under drought stress, the endogenous levels of ABA, jasmonic acid (JA), and salicylic acid (SA) increased; however, inoculation of YNA59 markedly reduced ABA (877 ± 22 ng/g) and JA (169.36 ± 20.74 ng/g) content, while it enhanced SA levels (176.55 ± 9.58 ng/g). Antioxidant analysis showed that the bacterial isolate YNA59 inoculated into broccoli plants contained significantly higher levels of SOD, CAT, and APX, with a decrease in GPX levels. The bacterial isolate YNA59 was therefore identified as Variovorax sp. YNA59. Our current findings suggest that newly isolated drought tolerant rhizospheric Variovorax sp. YNA59 is a useful stress-evading rhizobacterium that improved drought-stress tolerance of broccoli and could be used as a bio-fertilizer under drought conditions.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.303-309
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• 2013

This study was performed to clarify the effect of medium compositions and plant growth regulators on the shoot, root formation and growth of 'Jarang' grape for mass propagation of virus-free plant. The formation and growth of shoot were considerably favorable in half-concentration of MS medium. However, the formation of adventitious root per explants (avg. 2.1) was effective in higher concentration (two times) of MS medium. For sucrose concentration, 1% for the shoot formation, 3% for the adventitious root formation and 1% for the growth were observed as yield significant results. With the addition of 0.05% of activated carbon, the shoot growth was improved, and it was effective for the adventitious root formation and growth as well. A pH of 6.8 in the medium was the most suitable for mass propagation; the results showed significant enhancement in the number of nodes and the length of the shoot, 3.9 and 1.3 cm, respectively. The shoot growth was the most vigorous in BA 1.0 mg/L due to the impact of the growth regulator on the mass propagation in it. Consequently, 16.9 shoots per explant were formed in NAA 1.0 mg/L so good results were obtained.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.295-303
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• 1999

An experiment was conducted to evaluate the possibility of using basic oxygen furnace (BOF) slag as a soil conditioner in rice paddy field. In 1997, rice (Oryza sativa B. cv. Dongjinbyeo) crop was cultivated under different application rates of BOF slag at three different places, Inandong Sunchon city, Youjunglee Bosung province, and Nampyung Najoo city. In each paddy field, five treatments, four application rate of BOF slag (0, 4, 8, $12Mg\;ha^{-1}$) and one application rate of lime ($2Mg\;ha^{-1}$) were tried with three replications. Plant height, number of tillers per hill, leaf area per hill, leaf dry weight, calm dry weight or shoot dry weight per hill were measured five times at the interval of seven days. Chemical contents of rice plants and soil were also measured at the same sampling date Yield were estimated by harvesting $6.6m^2$ per experimental unit and yield components were measured by sampling 10 plants per experimental unit at the harvest date. Application of BOF slag hardly affected contents of soil organic matter, available phosphate and potassium in soil. Soil pH and contents of Ca, Mg, Fe and $SiO_2$ enhanced as BOF slag rate increased. Enhancement of soil pH by ROF slag treatment appeared to be closely related with increase in soil Ca content. Application tate of $2Mg\;ha^{-1}$ of lime showed almost the same effect, in increase of soil Ca content as application rate of $4{\sim}8Mg\;ha^{-1}$ of BOF slag, Fe content in soil decreased sharply as time passed after slag treatment and stabilized more or less at the later sampling date. Contents of inorganic matter in plant such as total nitrogen, phosphate, potassium and Mg were not affected by BOF slag treatment. However, contents of Ca, Fe, and $SiO_2$ in plants increased as slag rate became higher. The growth of rice plants with BOF slag treatment was more or less slower but continued persistently up to the later growth stage, so that growth of plants with BOF slag treatment was almost the same nr even greater than that of control or lime treatment. However, BOF slag rate of $12Mg\;ha^{-1}$ seemed to be too high because all the measurements of plant, growth at this rate showed lower values than those of other treatments at all the sampling dates. Treatments of BOF slag $4Mg\;ha^{-1}$ or $8Mg\;ha^{-1}$ showed higher rough rice yield than other treatments, so that the optimum BOF slag ratein rice paddy field seemed to be in the rage of $4{\sim}8Mg\;ha^{-1}$.

• Korean Journal of Medicinal Crop Science
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• v.16 no.1
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• pp.9-15
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• 2008

Immune-potentiation of Chicorium endivia L. were investigated on follows extracts associated with ultrasonification process at 60 kHz and showed the highest promotion of human B and T cell growth, about $10{\sim}20%$ compared to the control. The secretion of TNF-${\alpha}$ and IL-6 was also enhanced by the addition $(0.5mg/m{\ell})$ of the extracts. NK cell activation was Improved up to 1.37 times higher than the control, through adding extracts. It was also found that extracts from C. endivia L. could yield higher nitric oxide production from macrophage than Lipopolysaccaharides (LPS). It can be concluded that, in general, the extracts treated with ultrasonification has higher immune activity than others, possibly by higher yielding immune-modulatory activity than conventional extraction process. The optimum condition for the extraction of C. endivia L. is ethanol extraction at $60{\sim}100^{\circ}C$ associated with ultrasonification.

• Research in Plant Disease
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• v.23 no.3
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• pp.212-227
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• 2017

Pseudomonas chlororaphis O6, isolated from the roots of dryland, field-grown commercial wheat in the USA, enhances plant health and therefore it is used in agriculture as a biofertilizer and biocontrol agent. The metabolites produced by this pseudomonad stimulate plant growth through direct antagonism of pathogens and by inducing systemic resistance in the plant. Studies upon P. chlororaphis O6 identify the pathways through which defined bacterial metabolites generate protection against pathogenic microbes, insects, and nematodes. P. chlororaphis O6 also triggers plant resistance to drought and salinity stresses. The beneficial determinants are produced from bacterial cells as they form biofilms during root colonization. Molecular control these processes in P. chlororaphis O6 involves the global regulatory Gac/Rsm signaling cascade with cross-talk between other global regulatory pathways. The Gac/Rsm regulon allows for coordinate phasing of expression of the genes that encode these beneficial traits among a community of cells. This review provides insights on the Gac/Rsm regulon in expression of beneficial traits of the P. chlororaphis O6 which can contribute to help yield enhancement and quality in agricultural production.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.311-316
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• 1997

A high xylitol producing yeast was isolated from the sludge of xylose manufacturing factory and then identified as Candida tropicalis DS-72 according to physiological properties. The strain was able to produce xylitol in a high concentration up to 72g/l from 100g/l xylose in 32 hours. Medium optimization for xylitol production by C. tropicalis DS-72 was performed. Effect of various nitrogen sources on xylitol production was investigated. Of nitrogenous compounds, yeast extract was the most suitable organic nitrogen nutrient for the enhancement of xylitol production. However, inorganic nitrogen resulted in a low cell concentration and did not produce xylitol. Effect of inorganic salts such as KH$_{2}$PO$_{4}$, and MgSO$_{4}$, 7H$_{2}$O on xylitol production was also studied. Optimal medium was selected as xylose 100g/l, yeast extract 10g/l, KH$_{2}$PO$_{4}$, 5 g/l and MgSO$_{4}$, 7H$_{2}$O 0.2 g/l. Xylitol of 88 g/l was produced from 100 g/l xylose in 30 hours using the optimal medium in a flask. In a fermentor, a fed-batch culture with 300g/l xylose was carried out. A final xylitol concentration of 240 g/l in the culture could be obtained in 43 hours of culture time by maintaining the high level of dissolved oxygen during growth phase and limiting the dissolved oxygen in the same culture during production phase. This result corresponded to a xylitol yield of 80% and a xylitol productivity of 5.58 g/1-h.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.739-748
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• 2001

A self-organizing fuzzy logic controller using a genetic algorithm is described, which controlled the glucose concentration for the enhancement of flavonoid production in a fed-batch cultivation of Scutellaria baicalensis G. plant cells. The substrate feeding strategy in a fed-batch culture was to increase the flavonoid production by using the proposed kinetic model. For the two-stage culture, the substrate feeding strategy consisted of a first period with 28 g/I of glucose to promote cell growth, followed by a second period with 5 g/I of glucose to promote flavonoid production. A simple fuzzy logic controller and the self-organizing fuzzy logic controller using a genetic algorithm was constructed to control the glucose concentration in a fed-batch culture. The designed fuzzy logic controllers were applied to maintain the glucose concentration at given set-points of the two-stage culture in fed-batch cultivation. The experimental results showed that the self-organizing fuzzy logic controller improved the controller\`s performance, compared with that of the simple fuzzy logic controller. The specific production yield and productivity of flavonoids in the two-stage culture were higher than those in the batch culture.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.846-850
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• 2008

Technologies related to sealed-type ultrasonic sensors and driving circuit modules for them are the key elements for intelligent robot industry. Those technologies are believed to yield a drastic enhancement of the performance measuring distances in the intelligent robot systems. Modulization technologies of ultrasonic sensors are expected to develop ASIC and MEMS technologies in the future. The size of domestic market for sealed-type ultrasonic sensor modules is expected to grow to 1 billion and 5.72 billion Won by 2008 and 2012, respectively. Recent interest to service robots and government-driven programs are promoting the rapid growth of the market for the service robots. Successful application of the sealed-type ultrasonic modules to the service robots is expected to replace the conventional photo-sensors in a near future.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.364-368
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• 2006

Survival of biocontrol agents and their effective colonization of rhizhosphere are the essential components for successful disease suppression. The effects of hydrogel supplement on bacterial survival and disease control were evaluated in pot and in the field. Addition of 2% hydrogel material to potting soil resulted in significant enhancement of colonization of biocontrol agent Serratia plymuthica A21-4 both in soil and rhizosphere of pepper plants. Rhizosphere colonization of S. plymuthica A21-4 retrieved from 40 days old pepper seedlings indicated 100 times higher bacterial population in hydrogel treated soil than in ordinary pot soil. The pepper plants sown in hydrogelated potting soil showed higher seed germination rate and the better growth of pepper plant than those in ordinary commercial pot soil. Although the suppression of Phytophthora capsid density in the potting soil by treatment of biocontrol agent A21-4 was not significantly different between in hydrogelated soil and ordinary potting soil, the suppression of Phytophthora blight between two treatments was significantly different. A21-4 treatment in hydrogelated potting soil was completely disease-free while same treatment in ordinary potting soil revealed 36% disease incidence. Our field study under natural disease occurrence also showed significantly less disease incidence(12.3%) in the A21-4 treatment in the hydrogelated soil compared to other treatments. Yield promotion of pepper by the A21-4 treatment in the hydrogelated potting soil was also recognized. Our results indicated that hydrogel amendment with biocontrol agent in pot soil would be a good alternative to protect pepper seedlings and increase plant yield.