• The Korean Journal of Pharmacology
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• v.23 no.1
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• pp.51-56
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• 1987

Cyclobuxine D was extracted from Buxus microphylla var. koreana Nakai. The effects of cyclobuxine D on the biosynthesis of prostaglandins from arachidonic acid in guinea pig lung, prostaglandin production and leukocyte migration in carrageenin-induced inflammation was investigated. These effects of cyclobuxine D were compared with those of aspirin and dexamethasone. Cyclobuxine D does not inhibit significantly cyclooxygenase in guinea pig lung but reduces prostaglandin concentration and leukocyte migration in inflammatory exudates. These effects of cyclobuxine D differ from that of aspirin which inhibits biosynthesis of prostaglandin in vitro and has a relative small effect on leukocyte migration. Dexamethasone, which does not inhibit cyclooxygenase in vitro, has an effect similar to that of cyclobuxine D on leukocyte migration and prostaglandin production in inflammatory exudates.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.359-367
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• 1987

A method for evaluating bacterial chemotactic responses toward several single of combined sugars and sterile mucilage from the different rice cultivars had been tested. Bacterial genus of Azospirillum, Pseudomonas and Agrobacterium were specially identified from the histosphere of different rice cultivars and graminea grasses in saline and reclaimed saline paddy soil. To evaluate chemotaxis of these strains a modification of Fendrik channel method was used. Under this condition Azospirillum lipoferum Ecc 3-1 reacted stereoisomerically fomulating the single migration ring while Agrobacterium radiobacter Ecc 1-1 and Pseudomonas sp Ecc 4-1 did not. Strains specificities of chemotaxis to the single sugar such as D(+)-glucose and D(+)-fructose were less prominent than malic and citric acid. Chemotactic responses to the combined sugar such as D-galacturonic acid and the L-aspartate were found high attracting reaction than other combined sugars. Chemotaxis of associative $N_2$-fixing bacteria to the root exudates of different rice cultivars were differed among bacterial strains and rice cultivars.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.302-307
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• 2014

Many rhizobacteria can promote plant growth through various direct or indirect mechanisms, and their production of phytohormones such as indole-3-acetic acid (IAA) may have pronounced effects on growth and development of plants. Rhizobacterial strain isolated from rhizosphere of foxtail (Setaria viridis), Acinetobacter sp. SW5 produced 118.1 mg/L of IAA and 4.5 mg/L of gibberellin ($GA_3$) in brain heart broth medium at 2 and 1 day of incubation, respectively. In a pot test the lengths of stem and root and fresh weight of the germinated tomato seedlings treated with Acinetobacter sp. SW5 significantly increased by 26.3, 33.3, and 105.3%, respectively compared to those of the uninoculated control in 12 weeks of cultivation. When the root exudate secreted from tomato seedlings was analyzed by HPLC, 3.75 ng mg tomato $root^{-1}$ of tryptophan which is an IAA precursor was detected. Acinetobacter sp. SW5 could produce $4.06{\mu}M$ of IAA from root exudate from 8 tomato seedlings. Together with the capability of growth of Acinetobacter sp. SW5 in the tomato root exudates, this IAA secreted by bacteria might contribute to enhance the growth of tomato plants.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.225-238
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• 2021

CH₄-oxidizing and N₂O-reducing bacterial consortia were enriched from the rhizosphere soils of maize (Zea mays) and tall fescue (Festuca arundinacea). Illumina MiSeq sequencing analysis was performed to comparatively analyze the bacterial communities of the consortia with those of the rhizosphere soils. Additionally, the effect of root exudate on CH₄ oxidation and N₂O reduction activities of the microbes was evaluated. Although the inoculum sources varied, the CH₄-oxidizing and N₂O-reducing consortia derived from maize and tall fescue were similar. The predominant methanotrophs in the CH₄-oxidizing consortia were Methylosarcina, Methylococcus, and Methylocystis. Among the N₂O-reducing consortia, the representative N₂O-reducing bacteria were Cloacibacterium, Azonexus, and Klebsiella. The N₂O reduction rate of the N₂O-reducing consortium from maize rhizosphere and tall fescue rhizosphere increased by 1.6 and 2.7 times with the addition of maize and tall fescue root exudates, respectively. The CH₄ oxidization activity of the CH₄-oxidizing consortia did not increase with the addition of root exudates. The CH₄-oxidizing and N₂O-reducing consortia can be used as promising bioresources to mitigate non-CO₂ greenhouse gas emissions during remediation of oil-contaminated soils.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.193-202
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• 2011

We studied temperature sensitivity characteristics of soil respiration during periods of rising and falling temperatures within a common temperature range. We measured soil respiration continuously through two periods (a period of falling temperature, from August 7, 2003 to October 13, 2003; and a period of rising temperature from May 2, 2004 to July 2, 2004) using an open-top chamber technique. A clear exponential relationship was observed between soil temperature and soil respiration rate during both periods. However, the effects of soil water content were not significant, because the humid monsoon climate prevented soil drought, which would otherwise have limited soil respiration. We analyzed temperature sensitivity using the $Q_{10}$ value and $R_{ref}$ (reference respiration at the average temperature for the observation period) and found that these values tended to be higher during the period of rising temperature than during the period of falling temperature. In the absence of an effect on soil water content, several other factors could explain this phenomenon. Here, we discuss the factors that control temperature sensitivity of soil respiration during periods of rising and falling temperature, such as root respiration, root growth, root exudates, and litter supply. We also discuss how the contribution of these factors may vary due to different growth states or due to the effects of the previous season, despite a similar temperature range.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.88-89
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• 2006

Fowl cholera is an infectious disease caused by .Pasteurella multocida, affecting domesticated and wild birds. It usually appears as a septicemia of sudden onset with high morbidity and mortality, but chronic conditions that characterized by localized infections often occur. 13wks broiler breeders were submitted to the Kyung-pook national university for diagnosis. Clinical signs included approximately 1% mortality, severe lameness, ruffled feathers and swollen and/or cloudy eyes. At necropsy, the outstanding lesions were seen swollen hock joint, which were suppurative or caseous exudates, inflammation of conjunctiva, severe pneumonia and epicarditis. The causative agent was isolated from the hock joint, liver, sinus and sternum of the chickens, and performed physiological and biochemical test. To identify the serotype of P. multocida, capsular serotyping was conducted by multiplex polymerase chain reaction (PCR). In the antimicrobial susceptibility test, the isolates were resistance to the aminoglycosides. In this study, we confirmed chronic fowl cholera (FC) caused by P. multocida in broiler breeders in Korea.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.279-284
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• 2008

We investigated whether carboxylate exudation of Brassica pekinensis Rupr. was affected by nitrate deposition from simulated acid rain. A gas chromatographic (GC) analysis was employed for the determination of low molecular weight organic acids (LOA) in rhizosphere soils, bulk soil, roots and leaves of Brassica pekinensis Rupr.. Rhizosphere soils were collected after 8 weeks of plant growth by first removing the bulk soil from the root system and then by mechanical move off the rhizosphere soil that adhered to the root surface with soft brush. Soil and plant materials were simultaneously extracted with the mixture of methanol and sulfuric acid (100:7, v/v). Seven organic acids, oxalic, malonic, fumaric, succinic, maleic, L-malic and citric acid were identified and quantified by GC equipped with FID. Oxalic, L-malic, and citric acids were found in both the bulk and rhizosphere soils, while most LOAs were not detected in the control treatment. On the contrary, except maleic acid, all other organic acids were detected in the leaves and roots of cabbages treated with nitrate deposition.

• Environmental Engineering Research
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• v.21 no.2
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• pp.211-218
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• 2016

Cheonggye-cheon is a partly restored urban stream located in central Seoul. We monitored fecal contamination using three different fecal indicators, total coliforms (TC), fecal coliforms (FC) and E. coli, to assess differences in each indicator on days of varying weather conditions. Presumptive TC, FC and E. coli colonies were identified by their 16S rRNA sequences. The results showed that enumeration of E. coli provided a better reflection of fecal contamination of the stream than TC and FC. The main sources of contamination were the inflow of fecal-polluted groundwater from the vicinity of a subway line and two inflowing streams. The fecal contamination was worsened on days with heavy rain because untreated sewage from a collecting facility flowed into the stream. Moreover, growth potential of fecal indicator (E. coli) in situ induced by algal exudates was measured. Our results suggest that an appropriate standard based on E. coli rather than TC and FC should be established for improving water quality management strategies of Cheonggye-cheon in the future.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.384-387
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• 2017

A dead male Jeju weasel with clinical signs of severe dehydration and moribund was submitted for the necropsy. Grossly, purple-red ecchymoses were scattered in the surface of the entire lungs. Milky-white mucoid materials occupied in the left bronchial lumens. Histopathologically, an adult worm with thick cuticle layer surrounded by chronic inflammatory cells was embedded in the left caudal lung lobe. Numerous oval or barrel-shaped parasitic eggs with muco-purulent exudates were observed in the dilated bronchus of another section of left caudal lobe. Operculate parasitic eggs showed typical morphologic characteristics such as barrel shape with asymmetry bipolar plugs and thick bi-layered wall. Based on the histopathologic findings and morphological characteristics of parasitic eggs in the pulmonary tissue section, this case was diagnosed as verminous pneumonia associated Eucoleus aerophilus infection in Jeju weasel.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.121-127
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• 2003

Ornithobacterium rhinotracheale (OR) is a bacterium responsible for a respiratory disease in turkeys and chickens, and has been identified as one of the emerging respiratory bacterial pathogens. Ten cases of four hundred cases submitted to National Veterinary Research & Quarantine Service for diagnosis in 2001 and in 2002 were diagnosed as OR infection. The major clinical signs of chickens infected with OR were respiratory symptoms including sneezing, sniveling, wet eyes, and swelling of the sinus infraorbitalis at 3 to 4 weeks of age. At necropsy, gross lesions were commonly found to foamish, white, and yoghurt-like exudates in the peritonium and abdominal air sacs. Microscopically, epithelial metaplasia and proliferation of air sacs were prominant with accompaning inflammatory reactions characterized by heterophils, fibrins, and bacterial colonization. Ten field isolates were obtained from air sacs and peritonium of these affected chickens, and were identified as OR, resulted from by gram-staining, catalase, oxidase, API NE and API ZYM Kit. In additon, using a previously reported primer targeted to 16S rRNA of ORT, 784bp fragment was successfully amplified from templates extracted from the isolates and a reference strain. This report describes an occurrence of Ornithobacterium rhinotracheale infection in chickens in Korea.