• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.210-219
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• 2017

This study aimed to establish an optimal extraction process and high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method for determination of marker compounds, dihydrokaempferol (DHK) and 3-O-methylquercetin (3-MeQ), as a part of materials standardization for the development of health functional foods from stems of Opuntia ficus-indica var. saboten (OFS). The quantitative determination method of marker compounds was optimized by HPLC analysis, and the correlation coefficient for the calibration curve showed very good linearity. The HPLC-PDA method was applied successfully to quantification of marker compounds in OFS after validation of the method in terms of linearity, accuracy, and precision. Ethanolic extracts from stems of O. ficus-indica var. saboten (OFSEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 50, 70, and 80% ethanol for 3, 4, 5, and 6 h. Among OFSEs, OFS70E at $80^{\circ}C$ showed the highest contents of DHK and 3-MeQ of $26.42{\pm}0.65$ and $3.88{\pm}0.29mg/OFS100g$, respectively. Furthermore, OFSEs were determined for their antioxidant activities by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibitory activities in rat liver homogenate. OFS70E at $70^{\circ}C$ showed the most potent antioxidant activities with $IC_{50}$ values of $1.19{\pm}0.11$ and $0.89{\pm}0.09mg/mL$ in the DPPH radical scavenging and LPO inhibitory assays, respectively. To identify active components of OFS, various chromatographic separation of OFS70E led to isolation of 11 flavonoids: dihydrokaempferol, dihydroquercetin, 3-O-methylquercetin, quercetin, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-galactoside, narcissin, kaempferol 7-O-glucoside, quercetin 3-O-galactoside, isorhamnetin, and kaempferol 3-O-rutinoside. The results suggest that standardization of DHK in OFSEs using HPLC-PDA analysis would be an acceptable method for the development of health functional foods.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.843-859
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• 2017

The JK-1 isolate which was the best producer of indole-3-acetic acid and carotenoid among the 388 strains isolated from 28 wetlands in Jeju, was identified to be Rhodopseudomonas palustirs belongs to a typical group of non sulfur purple bacteria based on 16S sRNA sequencing. This study investigated the effect of different cultural conditions of pH, temperature, agitation, light and aeration on growth, IAA and carotenoid production of photosynthetic bacterium JK-1 for optimization of IAA and carotenoid production. It was found that growth, IAA, carotenoid, and bacteriochlorophyll production with light (3,000~3,500 Lux) and agitation (100 rpm) showed better results than those with dark/static or dark/agitation (100 rpm) in anaerobic conditions. The optimal pH, temperature and agitation speed for cell growth were 7, $30^{\circ}C$, 150 rpm, for IAA production were 9, $30^{\circ}C$, 150rpm and for carotenoid production were 6, $25^{\circ}C$, 50 rpm, cultured for 72 h under anaerobic light, respectively. The growth and IAA production were high in aerobic culture compared with anaerocic culture, whereas carotenoid and bacteriochlorophyll content were decreased extremely in aerobic condition (0.5~1 vvm). Subsequently, the optimal culture conditions for JK-1 were selected with pH 7, $30^{\circ}C$ and 100 rpm under anaerobic light and the effect on plant growth was tested by pot assay. Inoculation of JK-1 with 3% (v/v) level caused increase in shoot and root dry weigh that varied from 20%~58% to 40%~28% in young radish in camparison to uninoculated treatment at 50 days of growth. The study suggests that the JK-1 isolate may serve as efficient biofertilizer inoculants to promote plant growth.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.146-158
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• 2014

Camelina sativa that belongs to Brassicaceae family is an emerging oilseed crop. Camelina seeds contain approximately 40% storage oils per seed dry weight, which are useful for human and animal diets and industrial applications. Microsomal delta-12 fatty acid desaturase2 (FAD2) catalyzes the conversion of oleic acid to linoleic acid. The polymorphisms of FAD2 genes are correlated with the levels of oleic acids in seed oils. Microsomal delta-12 fatty acid desaturase2 (FAD2) catalyzes the conversion of oleic acid to linoleic acid. The polymorphisms of FAD2 genes are correlated with the levels of oleic acids in seed oils. In this study, three CsFAD2 genes (CsFAD2-1, CsFAD2-2 and CsFAD2-3.1) were isolated from developing seeds of Camelina sativa (L.) cv. CAME. The nucleotide and deduced amino acid sequences of three CsFAD2 genes were compared with those from dicotyledon and monocotyledon plants including Camelina cultivars Sunesone and SRS933. Three histidine motifs (HECGH, HRRHH, and HVAHH) required for FAD activity and a hydrophobic valine or isoleucine residue, which is a SNP (single nucleotide polymorphism) marker related with enzyme activity are well conserved in three CsFAD2s. The expressions of CsFAD2-1 and CsFAD2-3.1 were ubiquitously detected in various Camelina organs, whereas the CsFAD2-2 transcripts were predominantly detected in flowers and developing seeds. The contents of oleic acids decreased, whereas the amounts of linoleic acid increased in dry seeds of transgenic fad2-2 lines expressing each CsFAD2 gene compared with fad2-2 mutant, indicating that three CsFAD2 genes are functionally active. The isolated CsFAD2 genes might be applicable in metabolic engineering of storage oils with high oleic acids in oilseed crops.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.235-244
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• 2004

In this study, we compared the levels of methylotrophic bacterial community diversity in the leaf samples of 19 rice cultivars collected from three regions of Korea. Nineteen pink pigmented isolates showing characteristic growth on methanol were obtained. Physiological and biochemical characters of each isolate were examined according to methods described in Bergey's Manual of Systematic Bacteriology. When phylotypes were defined by performing numerical analysis of 37 characteristics, four distinct clusters were formed. The two reference strains, Methylobacterium extorquens AM1 and Methylobacterium fujisawaense KACC10744 were found to group under cluster IV and cluster III respectively. Cluster I diverged on the basis of nitrate reduction and four isolates showed tolerance upto 0.5 M NaCl concentrations. Two strains in cluster I and III were found to possess methane utilizing properties. Most of the isolates in all the four clusters utilized monosaccharides, disaccharide and polyols as carbon source. When the isolates were subjected for indole-3-acetic acid (IAA) analysis in the presence of L-tryptophan, only 8 isolates exhibited IAA production. In addition, the nitrogen source in the medium was found to influence the IAA production. Addition of $(NH_4)_2SO_4$ in the medium led to a 2 to 30 fold increase in the indole synthesis. However, $KNO_3$, $NH_4NO_3$ and $NH_4Cl$ substitution did not significantly stimulate the synthesis of IAA in the growth medium. Result of gnotobiotic root elongation assay significantly increased roots and shoots lengths, and number of lateral roots, which is mediated by IAA production in the culture medium. The rice seedlings primary roots from seeds treated with methylotrophic isolates were on average 27 to 56% longer than the roots from seeds treated with the uninoculated seeds. In addition, application of different high concentrations of authentic IAA ($400g\;mL^{-1}$) to roots of rice seedlings inhibited root growth. However, the IAA concentration from 10 to $200g\;mL^{-1}$, IAA promoted root growth of rice seedlings. These results suggest that bacterial IAA plays a major role in the development of the host plant root system.

• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.121-128
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• 1995

The characteristics of protein-bound polysaccharides (PBP) which were isolated and purified from the sawdust mycelia of Agrocybe cylindracea were investigated. The yield of crude protein-bound polysaccharides (Fr.CB) extracted with boiling water and precipitated with 95% ethanol, was 0.74% based on the original sawdust mycelia. The Fr.CB was purified by the membrane filtration, ion exchange chromatography and gel filtration. The Fr.B fraction of which the molecular weight is over 300 KDa, was isolated from the Fr.CB using membrane filtration, and the yield was 38.6% based on the Fr.CB. This result indicates that high molecular protein-bound polysaccharides are the dominent components of the Fr.CB. Two fractions (Fr.B-1, Fr.B-2) were also isolated from the Fr.B using ion exchange chromatography, and the yields were 17.3% (Fr.B-1) and 10.3% (Fr. B-2), respectively. The Fr.B-1 was concentrated and gel-filtrated, and the single peak, thought to be nearly pure protein-bound polysaccharides, was obtained. The yield of final fraction $(Fr.B-1-{\beta})$ was 42.5% based on the Fr.B-1. The molecular weight of $Fr.B-1-{\beta}$ was nearly 710 KDa. The monosaccharides' composition of $Fr.B-1-{\beta}$ was analized by HPLC, and glucose was the dominent component, and fucose and galactose were also detected. The result of amino acid analysis was that glutamic acid and analysis were detected to a significant level, and cysteine was not detected.

• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.362-371
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• 1996

This study was conducted to investigate the biochemical properties of isolated bacteria, low temperature tolerant methanogens which were selected for use as inoculum for anaerobic fermentation of agricultural and livestock wasted at low temperature. The results, obtained were summarized as follows: Low temperature tolerant methanogens were isolated from the samples which showed the high methanogenesis rate by enrichment culture at low temperature in methanol medium. These methanogens, Methanobacterium M-251 and Methanobacterium M-253 were isolated from swampy sediment at latitude $56.9^{\circ}$, Methanosarcina mazei M-372 from lake sediment IV at latitude $55.0^{\circ}$ N, and Methanobacterium formicicum M-375 from tidal land soil at latitude $37.0^{\circ}N$, respectively. The isolated anaerobic bacteria could not use sugars as carbon sources. The optimum pH value for the growth of M-251 and M-375 was 6.8, but those for M-253 and M-372 6.5 and 7.0, respectively. The minimum growth temperature of isolated, M-251 and M-253 were $8^{\circ}C$ and the optimum temperature $30^{\circ}C$, while the minimum of M-392 and M-395 were $13^{\circ}C$ and the optimum $37^{\circ}C$. The growth rate of isolates at $17.5^{\circ}C$ were lower by 32-50% than that of $30^{\circ}C$. The isolated Methanobacterium strains such as M-251, M-253, and M-375 have lower cell yield, 0.38-1.21g/1M $CH_4$ than 1.14-1.51g/1M $CH_4$ of Methanosarcina mazei M-372.

• 한국해양학회지
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• v.30 no.4
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• pp.320-331
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• 1995

The closely spaced cores were analyzed to find detailed reconstruction of paleoenvironments and sealable changes along the Delaware Bay coast. Three areas, Kitts Hummock Beach mars, the St. Jones River marsh, and Bowers marsh near the St. Jones River's mouth, were chosen because these areas are compose of their own geomorphic characteristics and sea-level history. since significance of the stratigraphic correlations was to determine sedimentary fancies and paleoenvironments, multidisciplinary methods such as lithological description, grain-size analysis, organic/inorganic content, water content, mineral composition, botanical analysis, micropaleontological analysis, and /SUP 14/C datings were performed. Five major divisions of marsh environments were recognized in the stratigraphic sections: freshwater marsh, initialfreshwater marsh, slightly brackish marsh, brackish marsh, and salt marsh. Most of the lower part in the stratigraphic sections show freshwater marsh. On the top of this, either brackish marsh or tidal flat/tidal stream was recorded. The pro-Holocene sediments consist of sand, mud, and sandy mud, The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene sediments consist of sand, mud, and sandy mud. The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene surface within short distances permitted the concurrent development of variable environments such as freshwater marsh, brackish marsh or salt marsh at similar elevations. The freshwater marsh in this case was formed in the areas of isolation, so saline-water cannot encroach upon these areas. This complex development of paleoenvironments leads to a difficulty in stratigraphic correlation and interpretation of local relative sea-level changes. The deposition of subsurface sediments was affected by sediment supply, compaction, fluvial activity, biological competition, local tectonics and isostacy, climate and local relative sea-level changes. It was interpreted that the positions in the changes from freshwater environments to brackish environments or ice versa are the turning points of transgressions and regressions. Therefore, multiple transgressions and regressions were identified in the stratigraphic sections of the study area.

• Journal of Life Science
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• v.22 no.8
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• pp.1114-1119
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• 2012

Bacteria are frequently contaminated during the collection and processing procedures of boar semen. Of the contaminants, Stenotrophomonas (S.) maltophilia is a Gram-negative bacterium that is widely distributed in a variety of habitats. Although PCR assays have been developed for the detection of S. maltophilia, they cross-react with some species of Xanthomonas. In this study, we designed a primer set for the detection of S. maltophilia in order to target the chiA (GenBank accession no. NC_010943) gene. The specific PCR products were amplified from S. maltophilia only, not from other tested strains that are frequently found in semen. The detection limit of the PCR was $1.5{\times}10^3$ CFU/ml with pure-cultured S. maltophilia and $1.5{\times}10^4$ CFU/ml with S. maltophilia spiked in semen. Twenty-six (5.9%) S. maltophilia were isolated from 440 semen samples. The PCR results exhibited 98.9% agreement with a comparison of S. maltophilia isolation. Also, the sensitivity and specificity of the PCR were 100% and 98.7%, respectively. In the antimicrobial susceptibility test, S. maltophilia isolates were highly susceptible to enrofloxacin and florfenicol, while the majority of them were resistant to amoxicillin/clavulanic acid, apramycin, ceftiofur, penicillin, and spectinomycin. These results indicated that the PCR using the chiA gene was proven to be reliable and effective for the detection of S. maltophilia with high levels of sensitivity and specificity.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.345-355
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• 2017

This study was conducted to evaluate rice seed disinfection efficacy of loess-sulfur for the suppression of Bakanae disease caused by Fusarium fujikuroi. Rice seeds were treated at different concentrations of loess-sulfur, soaking time and temperature, and combination of hot-water treatment. Rice cultivar, Shindongjin harvested from Bakanae disease-infested area in 2015, was used. Loess-sulfur was treated as follows; concentration of undiluted solution, 2%, 1% and 0.5%; soaking time of 24 and 48 hours; treatment temperature of $20^{\circ}C$ and $30^{\circ}C$; hot water treatment or not. Optimal conditions of rice seed disinfection were selected soaking time of 48 hours and the suspension of 0.5% and 1% loess-sulfur by investigating seed germination and isolation frequency of Fusarium spp. on Komada agar medium in vitro, and were established 3 disinfection conditions as hot water ($60^{\circ}C$, 10 min.) + 1% loess-sulfur ($20^{\circ}C$, 48 hours), 1% loess-sulfur only ($30^{\circ}C$, 48 hours) and 1% loess-sulfur only ($20^{\circ}C$, 48 hours) through additional test in greenhouse. Above 3 conditions were verified by rice seedling box and paddy field test in the way of investigating Bakanae diseased plants (%) and healthy plants (%). Consequently, most effective rice seed disinfection conditions on Bakanae disease were combination of hot water and 1% loess-sulfur and loess-sulfur only at $30^{\circ}C$. Furthermore, treatments with these conditions showed control value of 100% were maintained from seedling to the heading stage in the field. However, treatment of 1% loess-sulfur only at $20^{\circ}C$ showed low control value of 78.2% in paddy field. Hot water only treatment turned out to be an effective disinfection method when conducted thoroughly with $60^{\circ}C$, 10 min. However, it was thought additional soaking process with loess-sulfur after hot water treatment served more high control effect against Bakanae disease when rice seeds were disinfected on a large scale. This results expected rice seed disinfection with loess-sulfur were effectively and easily usable method if farmers had only one of either hot water-disinfector or seed-disinfector. In addition, loess-sulfur is well-known to farmers, simple to manufacture method and cheap.

• The Korean Journal of Mycology
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• v.20 no.4
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• pp.337-346
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• 1992

Trichoderma spp. are an effective control agent for damping-off or other plant diseases. The interaction between. T. hamatum and Rhizoctonia solani on the rhizosphere or surface soil were examined to assess the possible roles of antibiosis or competition in the mechanisms of biological control agents as a basic research. In a proportional comparison, total bacteria, fungi, actinomycetes and Trichoderma spp were 65%, 8.8%, 25.9% and 0.28% respectively in their distribution in the soil. Among Trichoderma spp isolated, the 5 species of Trichoderma spp were indentified as T. koninggii, T. pseudokoninggii, T. aureoviridi, T. hamatum and T. viride respectively. In a mycoparasitic test, one isolate of T. hamatum strain Tr-5 showed an enzymatic ability to break fungal hyphae into piecies and infected on the R. solani hyphae showing a parasitism. Spore germination of the all isolates of Trichoderma spp showed a 1.7-7.3% of germination in natural soil conditions, but the percentage was high in sterile soil indicating all the natural soil were fungistatic on conidia of Trichoderma spp. In rhizosphere competent assay in pea plant, the antagonistic T. hamatum, T. viride, T. koninggii, T. pseudokoninggii showed a colonizing upper soil depth in rhizosphere around 1-3 cm in root zone, but the colonizing ability was much reduced along the deeper the soil depth. Propagule density was decreased in deeper the soil layer. Disease development rate treated alone with plant pathogens, Fusarium solani, Rhizoctonia solani, Cylindrocarpon destructans increased, but disease incidence rate reduced in treatment with combinations with antagonistic T. hamatum strain Tr-5.