• Clean Technology
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• v.8 no.2
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• pp.77-83
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• 2002

The purpose of this study is to develop the efficient nutrient removal process and to verify operation and design parameters in domestic sewage. Endogenous nitrate respiration (ENR) was used for denitrification of nitrate in return sludge without additional organic carbon source. ENR reactor before the anaerobic tank enable to reduce nitrate below 3 mg/L and increase phosphate release at anaerobic reaction. Primary effluent during pilot scale plant were shown as TCOD/TP ratio of 40~60 and TCOD/TKN ratio of 5~7. Effluent concentrations were 10 to 12mg/L as TN and 1mg/L as TP respectively. In lab scale experiments endogenous denitrification rate of ENR reactor ranges from 0.042 to $0.057gNO_3-N/gMv.d.$ $SP_{rel}/SCOD_{rm}$ was shown as from 0.13 to 0.17 in anaerobic reaction. These kinetic parameters are expected to be available for BNR(Biological Nutrient Removal) plant design and ENR reaction is available for nutrient removal in low strength wastewater.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.361-368
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• 2009

Cenangium ferruginosum was known as the causal agent of dieback of pines including Pinus koraiensis and Pinus densiflora. Since the first report of the disease in Korea in 1989, a group dying occurred in Seoul, Gyeonggi, Kangwon and Chungbuk in 2007 spring. Although C. ferreginosum was known as a weak pathogen or a parasite, this disease caused in stressed pine by drought, wounding, extremely cold weather or unusual warm winter. In this study, we explained the features of cenangium dieback with the characteristics of pathogen to understand the trend of disease associated with the climatic change of the world. We collected pycnidia and apothecia from the diseased branches and stems of P. koraiensis and P. densiflora in Gyeonggi, Chungcheong and Gyeongsang province to characterization of pathogen. The fungal development on the diseased branches were observed and the isolates from pycnidia and apothecia were identified as Cenangium ferruginosum by their morphological characteristics and the molecular techniques.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.18-24
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• 2003

For researching nitrogen-fixing bacteria associated with gramineous crops, we collected growing roots of rices, wheats, oats, barleys, ryes, and maizes at 19 sites of southern Korean peninsula. Endophytes and free living bacteria were isolated from those crop roots. Sixty-three isolates were classified on the basis of different morphology, size, color, host of colony, and the 16S rDNAs sequence. The analyses of PCR amplification for nifH gene and nitrogenase activity assay, revealed that all isolates contained nitrogen-fixing abilities. In addition, most of them have cellulase activity which is one of the common features of endophytic bacteria from plant.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.422-428
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• 2014

Endophytic bacterial strains from root tissue of strawberry were screened for their efficacy in growth improvement and control of Phytophthora blight disease of chili pepper plant under greenhouse condition. Plants treated with the strain EP103, identified as Pseudomonas fluorescens, showed growth improvement in terms of fresh weight and root length compared to the untreated control and other endophytic strains. When challenged with Phytophthora capsici, there was significant reduction of disease in EP103 treated plants with an efficacy of 78.7%. There was no direct inhibition of the target pathogen by EP103 when tested under in vitro antibiosis assay. Analysis of differential expression of selected marker genes for induced systemic resistance (ISR) in plants treated with EP103 and challenged with P. capsici showed up-regulation of PR1 and PR10 pathogenesis-related (PR) proteins. PCR analysis showed that EP103 produced secondary metabolites such as pyoluteorin, pyrrolnitrin, hydrogen cyanide and orfamide A. This study indicated the potential of endophytic P. fluorescens strain EP103 as an efficient biocontrol agent against P. capsici in chili pepper plant.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.169-175
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• 2007

The Bio Best Bacillus(B3) and Rotating Activated Bacillus Contactor(RABC) processes, in which Bacillus strains are predominating, are reported to remove nitrogen and phosphorus as well as organic matter effectively. Nevertheless the nutrient removal characteristics of the Bacillus strains have not been studied in detail so far. This study investigated the organic and nutrient removal by Bacillus strains, Bacillus megaterium(KCTC 3007), Paenibacillus polymyxa(KCTC 3627), and Bacillus sp. A12, C21, F12, and L1(isolated from a B3 process), by incubating the strains in 0.2% nutrient broth at $30^{\circ}C$. Burkholderia cepacia(KCTC 2966), a common activated sludge organism, was used as a reference species for comparison. Although the degradation rate was affected by the population sire, the specific removal rates of organic matter by Bacillus strains were greater by $2\sim5$ times than that of Burkholderia. In particular, the culture bottles inoculated with the endospores of Bacillus megaterium and Bacillus sp. C21, F12, and N12 showed significantly higher degradation rate than those of vegetative cells.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.341-345
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• 2007

Fifty endophytic bacteria, which produced slime around the colonies, were isolated from Pueraria roots. In particular, HDN-14, TDG-3, and TNB-3 strains, which appeared to be high viscosity producers, were selected. These strains produced high levels of polysaccharides in Puerara root medium extract. The purified polysaccharide was digested with 1N HCI and analyzed by HPLC, with glucose ($45.6{\sim}63.1%$), maltose ($14.6{\sim}23.7%$), and fructose ($17.4{\sim}23.7%$) detected as constitutive sugars. When determined by the homology relationship of the 16S rDNA sequence with the relative taxa, the HDN-14 and TNB-3 strains were closely ($99.06{\sim}99.32%$) related to the Pseudomonas $koreensis^T$ and Pseudomonas $jessenii^T$, while TDG-3 were closely ($99.48{\sim}99.74%$) related to Pseudomonas $plecoglossicida^T$, Pseudomonas $mosselii^T$, and Pseudomonas $monteilii^T$. The major cellular Pseudomonas acids are $3OH-C_{10:0}$, $2OH-C_{12:0}$, $3OH-C_{12:0}$, and $3OH-C_{12:1}$, with these strains being further differentiated in species belonging to the genus Pseudomonas.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.1-5
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• 2005

While the rusty-colored root is common in ginsengs culture and, often results in a severe economic loss, the major factors have not been found. This study was focused on the determination of a potential relationship between rusty root and endophytic bacteria. The number of endophytes was $9.6\;{\times}\;10^1{\sim}1.5\;{\times}\;10^2\;cfu/g$ fw in normal ginseng roots compared to $3.7\;{\times}\;10^6{\sim}5.1\;{\times}\;10^7\;cfu/g$ fw in rusty ones. Of 31 isolates from rusty ginseng roots, twenty-four isolates repeatedly induced severe to moderate rust on root while seven isolates induced slight rust. The bacteria responsible for rusty ginseng roots were mainly Gram negative aerobic. Rust inducing bacteria were identified as Agrobacterium tumefaciens, A. rhizogenes, Burkholderia phenazinium, Ensifer adharens, Lysobacter gummosus, Microbacterium luteolum, M. oxydans, Pseudomonas marginalis, P. veronii, Pseudomonas sp., Rhizobium leguminosarum, R. tropica, Rhodococcus erythropolis, Rh. globerulus, Variovorax paradoxus on the basis of bacteriological characters and 16S rDNA sequences analysis. The results in this study strongly suggested that the rusty ginseng roots were produced by infection and growth of endophytic bacteria.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.91-95
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• 1998

Cellulase producing microorganisms, GPC-1, GPC-2, GNR-1 GNR-2, and GNR-3, were screened from the Rumen fluid of Korean Native Cattle. Isolated GPC-1 and GPC-2 were identified as Ruminococcus sp. according to results of the Gram stain and anaerobic characteristics. Based on morphological and physicochemical identification, the isolate GPC-1 and GPC-2 were identified as strains of Ruminococcus albus and Ruminococcus flavefaciens, respectively. Isolated GNR-1 GNR-2 and GNR-3 were identified as Bacteroides sp., Butyrivibrio sp. and Clostridium sp. according to results of the Gram stain, $H_2S$ producition and spore formation, respectively. Based on morphological and physicochemical identification, the isolate GNR-1 GNR-2 and GNR-3 were identified as strains of Bacteroides succinogenes, Butyrivibrio fibrisolvens and Clostridium cellobioparum, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1002-1007
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• 2010

The study was performed to investigate the influence on growth and development of grape-cuttings by arbuscular mycorrhizal (AM) fungi inoculation, AM colonization rate, and the phenomena of mycorrhizal association. Among the grape-cuttings, 'Kyoho' and 'Tamnara' cultivars inoculated with AM fungi showed significantly increase of leaf area, leaf number, total root length and root surface area than non-infected ones. But 'Cambell Early' did not showed any significant difference in total root length and root surface area even after the inoculation. The AM colonization rates in mycorrhizal inoculation treatment were 22.5-32.5% in total average after 8weeks, and were 29.6%, 28.8%, and 48.8% for 'Cambell Early', 'Tamnara', and 'Kyoho' respectively after 12weeks. The AM colonization rate marked very low level in non-colonization control plot.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.229-234
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• 1988

To evaluate potential of VA mycorrhizal fungi for promoting growth of nitrogen-fixing trees and efficiency of fungal inoculation in relation to soil fertility and dual inoculation with bacteria, Alnus firma was grown for six months in pots with steam-sterilized soil after inoculation with Glomus mosseae, and Robinia pseudoacacia was grown in the fumigated field after inoculation with native Glomus sp. and Gigaspora sp. In unfertilized Alnus plants, 27% increase in dry weight(or 18% in height) was observed by Glomus inoculation, while plants inoculated with both VA mycorrhiza and actinomycete(crushed nodule inoculum) showed synergistic effect of 83% dry weight increase over uninoculated plants. In fertilized Alnus plants, mycorrhizal inoculation alone or dual inoculation with actinomycete resulted in depression of height and dry weight of plants. In case of Robinia, dual inoculation stimulated height growth by 23% (or dry weight by 25%) over the control in unfertilized field, while 13% more height growth(or 21% more dry weight) was observed in fertilized field. It is concluded that VA mycorrhizae, especially Glomus mosseae, have a potential for growth enhancement in Alnus, that synergistic effect of dual inoculation(mycorrhiza + actinomycete) exists in both Alnus and Robinia, and that responses of these plants to VA mycorrhiza are more pronounced in unfertilized soil.