• Journal of Microbiology and Biotechnology
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• v.30 no.5
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• pp.689-699
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• 2020

Brevibacillus brevis GZDF3 is a gram-positive, plant growth-promoting rhizosphere bacterium (PGPR) isolated from the rhizosphere soil of Pinellia ternata (an important herb in traditional Chinese medicine). The GZDF3 strain produces certain active compounds, such as siderophores, which are the final metabolite products of non-ribosomal peptide synthetase (NRPS) and independent non-ribosomal peptide synthetase (NIS) activity. With the present study, we attempted to investigate the siderophore production characteristics and conditions of Bacillus sp. GZDF3. The antibacterial activity of the siderophores on pathogenic fungi was also investigated. Optimal conditions for the synthesis of siderophores were determined by single factor method, using sucrose 15 g/l, asparagine 2 g/l, 32℃, and 48 h. The optimized sucrose asparagine medium significantly increased the production of siderophores, from 27.09% to 54.99%. Moreover, the effects of different kinds of metal ions on siderophore production were explored here. We found that Fe³⁺ and Cu²⁺ significantly inhibited the synthesis of siderophores. The preliminary separation and purification of siderophores by immobilized-metal affinity chromatography (IMAC) provides strong antibacterial activity against Candida albicans. The synergistic effect of siderophores and amphotericin B was also demonstrated. Our results have shown that the GZDF3 strain could produce a large amount of siderophores with strong antagonistic activity, which is helpful in the development of new biological control agents.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.39-45
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• 2016

BACKGROUND: This study aimed to evaluate the combined effects of three components (NPK) of chemical fertilizers with basal application of compost on soil organisms.METHODS AND RESULTS: The soil was treated with five treatments continuously for 15 years: control, PK, NK, NP and NPK. The application of N increased plant growth or biomass, and enhanced organic matter content in the soils. Levels of microbial phospholipid fatty acids (PLFAs) in the soils did not show marked differences among the soils treated with different treatments. However, the principal component analysis showed the changes in the structure of the microbial community in the soil, depending on treatments added. Nitrogen application caused a decrease of pH and an increase of EC in the soils, and these environmental stresses appeared to offset the promoting effect of increased organic matter content on microbial abundance. The abundance of bacterivorous nematodes was the highest in the soils after treating NPK; however, the abundance of fungivorous nematodes was unaffected. There was no significant correlation between the abundances of microbial groups and their feeders. Organic matter content was significantly correlated with the abundance of nematodes in the soils.CONCLUSION: Our results showed that chemical fertilizers affect the soil food chains through both biotic and abiotic factors, and a trophic cascade in the soils may not occur in response to long-term fertilization.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.36-41
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• 1994

The major objective of this study is to develop a method of zone cooling during summer day using heat pump for year- round cultivation. The efficiency of cold water cooling and fog cooling was investigated. In order to prevent the occurrence of blossom - end rot in tomato, cooling was induced together with air flow of the fruit treatment as well as promoting air circulation in the plant treatment was induced. The following results were obtained : 1) The temperature in the cold water cooling district was 1$0^{\circ}C$ lower than greenhouse temperature and the temperature in the fo8 cooling district was about 5$^{\circ}C$ lower than the greenhouse. 2) Regardless of cooling method, the treatment of air flow on fruit did not affect the fruit but prevent blossom-end rot. There was 34.5% occurrence rate of blossom -end rot in non-air flow district of cold water cooling 54.5% in non-air flow district of fog cooling and 78% in fog circulation cooling district. The cooling efficiency using cold water cooling method induced enough cooling at critical temperature for growth and development and the occurrence of blossom -end rot was lower than fog cooling. Fog cooling in culture district with air circulation did not induce and difference in temperature but caused an Increase in humidity resulting in 24% increase in the occurrence of blossom-end rot. Thus the occurrence of blossom-end rot in tomato caused by environmental factors can be attributed more to humidity than to temperature.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.190-196
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• 2012

In this study, a total of more than 1,000 bacteria, including 739 species of aerobic bacteria, 80 species of urease producing bacteria and 303 species of photosynthetic bacteria, were isolated from red-pepper field soils located in the Gyeongsan Province of the Republic of Korea. Amongst these, 158 species of aerobic bacteria, 70 species of urease producing bacteria and 228 species of photosynthetic bacteria were found to be auxin producing soil bacteria through quantification analysis with the Salkowski test. The latter groupings were then tested for antifungal activities to ${\beta}$-Glucanase and siderophore using CMC congo red agar and CAS blue agar media. In addition, the selected strains were examined for antifungal activity against various phytopathogenic fungi on PDN agar media. Six strains; BCB14, BCB17, C10, HA46, HA143, and HJ5, were noted for their ability to both produce auxin and act as antifungal substances. 16S rDNA sequence comparison analyses of these six strains identified them as Bacillus subtilis BCB14, B. methylotrophicus BCB17, B. methylotrophicus C10, B. sonorensis HA46, B. subtilis HA143, and B. safensis HJ5.

• Journal of Life Science
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• v.29 no.2
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• pp.198-201
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• 2019

Recently, it has been reported that Bacillus mojavensis possesses antifungal properties and plant growth-promoting activities, which are similar to the characteristics of siderophore. In this study, the siderophore produced by B. mojavensis was assessed using a solid phase extraction (SPE) cartridge and liquid chromatography quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS). After B. mojavensis was incubated in phenol medium for 16 hr and lyophilized, the sample was dissolved in water and loaded to an SPE cartridge to remove interferences. The cartridge was washed with 5% methanol in water and eluted with 2% formic acid in methanol sequentially. The eluted solution was evaporated under a stream of nitrogen gas and reconstituted in methanol. The reconstituted sample was filtered, and $1{\mu}l$ of the sample was assessed using Q-TOF MS/MS. The mass spectrometer was operated using the positive electrospray ionization mode. Based on the mass spectrum and tandem mass spectrum, the siderophore produced by B. mojavensis was bacillibactin, one of the catechol types of siderophore with a molecular weight of 882.2556. This siderophore analysis could provide a justification for the study of B. mojavensis as a functional food and for pharmaceutical applications.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.414-421
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• 2022

In this study, we isolated Weizmannia ginsengihumi LGHNH (KCTC 14462BP) from 30-year-old wild Panax ginseng C.A. Meyer and elucidated the characteristics of the isolated bacterium and its industrial potential as an anti-aging material. W. ginsengihumi LGHNH was investigated to produce indole-3-acetic acid (IAA), a plant growth-promoting hormone (1.38 ㎍/ml to 2.22 ㎍/ml). We also confirmed the existence of bioconversion activity via the comparison of the ginsenoside content before and after fermentation. As for the converted minor ginsenoside, Rg2(R), Rg4, Rg6, Rg3(S), Rg3(R), Rk1, Rg5, Rh1(R), Rk3 and Rh4 are known to have high bioavailability and various skin effects. We measured mitochondrial membrane potential and ATP biosynthesis to elucidate W. ginsengihumi LGHNH cultured product (WCP) as an anti-aging material. As a result, the mitochondrial membrane potential in HaCaT cells with UVB decreased to 39.3% compared to the unirradiated group, but was recovered to 57.3% and 58.1% by 0.001% (v/v) and 0.01% (v/v) WCP, respectively. In addition, we measured mitochondrial ATP biosynthesis. It decreased to 94.3% compared to the unirradiated group with UVB, but was recovered to 105.3% and 105.7% by 0.001% (v/v) and 0.01% (v/v) WCP.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.2
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• pp.105-114
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• 2018

The aim of this study was to evaluate the change of phenolic compounds after phosphite treatment on Cheorwon onion. Onion is a perennial plant belonging to the lily family. It is native to Persia of Southwest Asia. It is widely cultivated in the temperate regions of the world. Onion is a good name for the 'Okchong' to drop blood cholesterol and cardiovascular blood flow to increase the prevention of adult diseases. Cheorwon area is inland, but it has high continental climate due to its high altitude. Therefore it is said that the onion cultivated in this region has higher sugar content and higher taste than onion grown in the southern region. Phosphorus components are particularly important ingredients for promoting muscle development. However, if the phosphoric acid content of the soil part is maintained to a large extent until the harvest, the competition of the nutrients tends to cause decay of the root part. Therefore, it is important to improve the quality and shelf life of onion by inducing nutrient balance by applying foliar fertilization method on the reducing phosphorus at harvest time. In this study, acidity was controlled by diluting phosphorous acid(H₃PO₃) and potassium hydroxide(KOH), followed by leaf surface treatment with phosphite on onion. In this study, the concentration of phosphite was diluted to 500, 1,000, 1,500ppm and sprayed three times over the onion leaves in May 2018 using an atomizer and harvested at the end of June, and the phenolic compounds were analyzed by HPLC. As a result, the content of quercetin, one of the important substances in onion, was phosphite 500ppm(179.70㎍/g), 1,000(150.27), 1,500(105.95). The contents of caffeic acid, p-coumaric acid, ferulic acid, rutin, kaempferol, and sugar content were higher in the treatments than in the control. Therefore, the phosphite does not have a great influence on the growth, but it may play a role as a method of achieving balance with nitrogen in the rainy season by supplying the role of the material catalyst and the water soluble phosphoric acid and the potassium in the influence of the material change.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.677-686
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• 2018

This study was carried out to determine the effect of Kluyvera sp. CL-2 (KACC 91283P) on the growth of watermelon (Citrullus vulgaris L.). The study consisted of three treatments, no treatment (NT), twice application of Kluyvera sp. CL-2 before transplanting (KC1), and five times application around transplanting (KC2). We determined the chemical properties of soil before and after the treatments, and compared the growth characteristics of watermelon among treatments. The treatment of Kluyvera sp. CL-2 at $1.0{\times}10^6cfu\;mL^{-1}$ significantly increased available $P_2O_5$. The organic matter showed to increase for all treatments, while soil pH, exchangeable Ca and Mg tended to decrease for all treatments. The leaf width was increased by 11.6% for KC1 and 26.2% for KC2 compared to NT. But there were no significant differences in yield, leaf length, fruit weight, fruit length, fruit width, and pericarp thickness among treatments. The contents of free sugars such as fructose and glucose were increased by microbial treatments but sucrose was not different from NT. The content of glucose in watermelon was increased by 13.8% in KC1 and 12.8% in KC2 compared to NT. The content of fructose increased by 14.6% in KC1 and by 39.8% in KC2 compared to NT. The results from the study imply that Kluyvera sp. CL-2 can be used to increase sugar content in watermelon.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.26-27
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• 2018

With entry into force of the Nagoya Protocol to promote the fair sharing of the benefits of accessing and utilizing genetic resources, much support has been given to research on the development of biomaterials and products using domestic natural resources. Conservation and resource-saving of native species became very important through Nagoya Protocol enactment. The trend of cosmetic industry has been shifing from use synthetic chemicals to natural biomaterials, due to the safety regulations on new materials, ban on animal experiments, and expansion of cosmeceuticals range. In addition, functional cosmetic range has been expanded from whitening, wrinkle improvement, and ultraviolet shielding, to hair loss, hair loss alleviation, acne relaxation, and moisturizing of atopic skin, thus causing the activation of research about field of efficacy evaluation on natural biomaterials and commercialization. Chungbuk province is fostering the bio industry as a key industry for regional economic growth. For this purpose, Osong Biotechnology Complex/Ochang Science Industrial Complex in middle area, Jecheon biovalley in northern region, and Chungju Enterprise city have been established, thus playing a pivotal role in Bio innovative cluster in Korea. In particular, it was established the osong cosmetics clinical research support center to develop the cosmetics industry in chungbuk, thereby supporting clinical trials, efficacy evaluations, overseas certification, and overseas market entry in order to advance into the global market. In addition, oriental plants such as astragalus propinquus, schisandra chinensis, eucommia, alpiniae oxyphyllae fructus and biancaea sappan are being actively studied as global cosmetic ingredients through the promotion of various national research and development projects using natural materials in chungbuk province. The chungbuk natural product industry is expected to grow further throughout cosmetics industry development in the future, as companies and research institutes are actively promoting the secure index of effective material in natural products and effective material commercialization.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.201-209
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• 2014

This study was carried out in order to develop a biological control of anthracnose of red pepper caused by fungal pathogens. In particular, this study focuses on the Colletotrichum species, which includes important fungal pathogens causing a great deal of damage to red pepper. Antagonistic bacteria were isolated from the soil of pepper fields, which were then tested for biocontrol activity against the Colletotrichum gloeosporioides anthracnose pathogen of pepper. Based on the 16S rRNA sequence analysis, the isolated bacterial strain CS-52 was identical to Bacillus sp. The culture broth of Bacillus sp. CS-52 had antifungal activity toward the hyphae and spores of C. gloeosporioides. Moreover, the substances with antifungal activity were optimized when Bacillus sp. CS-52 was grown aerobically in a medium composed of 0.5% glucose, 0.7% $K_2HPO_4$, 0.2% $KH_2PO_4$, 0.3% $NH_4NO_3$, 0.01% $MnSO_4{\cdot}7H_2O$, and 0.15% yeast extract at $30^{\circ}C$. The inhibition of spore formation resulting from cellulase, siderophores, and indole-3-acetic acid (IAA), were produced at 24 h, 48 h, and 72 h, respectively. Bacillus sp. CS-52 also exhibited its potent fungicidal activity against anthracnose in an in vivo test, at a level of 70% when compared to chemical fungicides. These results identified substances with antifungal activity produced by Bacillus sp. CS-52 for the biological control of major plant pathogens in red pepper. Further studies will investigate the synergistic effect promoting better growth and antifungal activity by the formulation of substances with antifungal activity.