• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.227-231
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• 1990

A pot experiment was conducted to find out the effect of zeolite application on the growth and $N^2$ fixation of pea plants. The results are as follows. 1) The dry weight of pea plants grown with N-fertilizer application was smaller than that without N, but In was increased by application of zeolite 2) The N content in pea plants was increased by zeolite application. The N increment was smaller in 2% zeolite plots than in 1% zeolite plots. Larger amount of Ammonium were remained in the former plots. 3) The N amounts accumulated in different parts of plant derived from $^{15}N$-labelled fertilizer were decreased by application of zeolite. 4) The N derived from atmuspheric $N_2$ was increased by zeolite application. However, the application of fertilizer nitrogen depressed the enhancement of fixed-N accumulation.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.117-125
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• 2006

A microorganism capable of degrading toluene was isolated from crude oil contaminated soil and identified as Pseudomonas fluorescence. The effects of environmental factors on the degradation of toluene were investigated. The optimum temperature for toluene degradation was $30^{\circ}C$ and the maximum specific cell growth and toluene degradation rates were $0.76hr^{-1}$ and $0.36hr^{-1}$, respectively. Although the wild cells were not able to degrade toluene at $10^{\circ}C$ and $40^{\circ}C$, the cells adapted to toluene at $30^{\circ}C$ degraded 100mg/L of toluene completely at $10^{\circ}C$ and 80% of the toluene at $40^{\circ}C$. The wild cells were not able to degrade more than 200mg/L of toluene but the toluene-adapted cells degraded up to 300mg/L of toluene. Although the optimum pH was 7.0, the degradation rates were not much different in the range of 5.5 to 9.0. When nitrate was used as a nitrogen source instead of ammonium, the adaptation period became longer by 2~10 hours and the cell growth yield became lower by 45%. The toluene degradation rates after adaptation period, however, were almost same in both cases. The observations in this study will be used in the future biofilter design and operation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.362-372
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• 2010

In order to understand what leads to the appearance of harmful Chattonella algae in the Yeosu coastal waters of Korea, we measured environmental parameters every week at one station from May to November, 2006, and April to October, 2007. Four species of Chattonella appeared during the monitoring period: C. antiqua, C. globosa, C. marina and C. ovata. The range of water temperature and salinity were $15.0-27.9^{\circ}C$ and 17.6~33.0 psu, respectively, when Chattonella appeared, and their maximum cell density (4,840 cells/L) was at $27.1^{\circ}C$ and 33.0 psu. During the monitoring periods, the range of dissolved inorganic nitrogen (DIN), phosphate (DIP) and chlorophyll $\alpha$ (Chl-$\alpha$) concentrations in surface waters were $1.20-52.23\;{\mu}M$ ($8.59{\pm}8.97\;{\mu}M$), $0.03-1.56\;{\mu}M$ ($0.47{\pm}0.31\;{\mu}M$) and $0.45-31.12\;{\mu}g/L$ ($3.58{\pm}4.77\;{\mu}g/L$), respectively. Chattonella occurred at low cell density when the Chl-$\alpha$ concentration increased because of supplied nutrients, whereas their cell density increased during the periods of rapid decrease in Chl-$\alpha$. The results of growth experiments based on batch culture showed that the half saturation constant ($K_s$) of C. antiqua on ammonium (${NH_4}^-$), nitrate (${NO_3}^-$) and phosphate (${PO_4}^{2-}$) were $3.89{\mu}M$, $5.01\;{\mu}M$ and $0.63\;{\mu}M$, respectively. These Ks values are higher than those reported for diatoms and other flagellates at the DIP concentration (average $0.47{\mu}M$) of Yeosu coastal waters. Although the maximum specific growth rate (${\mu}_{max}$) of C. antiqua was lower than diatoms, it was higher than those of other flagellates. Therefore, our results indicate that the DIP level in the study area was too low to support Chattonella blooms, although Chattonella species have physiological characteristics that enable them to grow more rapidly than other flagellates when nutrient levels are higher than their $K_s$.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1202-1208
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• 2009

Synbiotics is the term used for a mixture of probiotics (live microbial feed additives that beneficially affects the host animal) and prebiotics (non-digestible food ingredients that beneficially affect the organism). This study investigated the effect of probiotics from anaerobic microflora with prebiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in weaning pigs. 150 pigs with an initial BW of 6.80${\pm}$0.32 kg (20 d of age) were randomly assigned to 5 dietary treatments as follows: i) US, basal diet+0.15% antibiotics (0.05% oxytetracycline 200 and 0.10% tiamulin 38 g), ii) BS, basal diet+0.2% synbiotics (probiotics from bacteria), iii) YS, basal diet+0.2% synbiotics (probiotics from yeast), iv) MS, basal diet+0.2% synbiotics (probiotics from mold), v) CS, basal diet+0.2% synbiotics (from compounds of bacteria, yeast and mold). The probiotics were contained in $10^{9}$ cfu/ml, $10^{5}$ cfu/ml and $10^{3}$ tfu/ml of bacteria, yeast and molds, respectively. The same prebiotics (mannan oligosaccharide, lactose, sodium acetate and ammonium citrate) was used for all the synbiotics. Pigs were housed individually for a 16-day experimental period. Growth performance showed no significant difference between antibiotic treatments and synbiotics-added treatments. The BS treatment showed higher (p<0.05) dry matter (DM) and nitrogen digestibility while ether extract and crude fiber digestibility were not affected by the dietary treatment. Also, the BS treatment decreased (p<0.05) fecal ammonia and amine gas emissions. Hydrogen sulfide concentration was also decreased (p<0.05) in BS, YS and MS treatments compared to other treatments. Moreover, all the synbioticsadded treatments increased fecal acetic acid concentration while the CS treatment had lower propionic acid concentration than the US treatment (p<0.05) gas emissions but decreased in fecal propionate gas emissions. Total fecal bacteria and Escherichia coli populations did not differ significantly among the treatments, while the Shigella counts were decreased (p<0.05) in synbiotics-included treatment. Fecal bacteria population was higher in the YS treatment than other treatments (p<0.05). The BS treatment had higher yeast concentration than YS, MS and CS treatments, while US treatment had higher mold concentrations than MS treatment (p<0.05). Therefore, the results of the present study suggest that synbiotics are as effective as antibiotics on growth performance, nutrient digestibility and fecal microflora composition in weaning pigs. Additionally, synbiotics from anaerobic microflora can decrease fecal noxious gas emission and synbiotics can substitute for antibiotics in weaning pigs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.150-158
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• 1993

In order to investigate the content and seasonal variation of the extractive components including taste compounds, free amino acids, nucleotides and related compounds, quanternary ammonium bases, and guanidino compounds of ascidian collected from the south coast of Korea were determined bimonthy from April to October in 1990. The extractive nitrogen was composed of $60{\sim}62\%$ as free amino acids, $12{\sim}16\%$ as betaines, $5{\sim}9\%$ as nucleotides, and others as trimethylamine oxide(TMAO) and total creatinine. The muscle of ascidian was rich in such free amino acids as taurine, proline, glutamic acid, glycine and glycinebetaine. Most of nitrogenous compounds in the extractives showed a marked seasonal variation with a maximum in summer or autumn. AMP content was relatively high among nucleotides. Succinic acid, malic acid, lactic acid and pyroglutaric acid were the major organic acids in ascidian. The results of omission test suggested that the taste of ascidian is attributed to mainly free amino acid, betaines, nucleotides and nonvolatile organic acid in order.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.100-106
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• 1995

This study was conducted to find the factors affecting somatic embryogenesis in suspension culture of Rehmania glutinosa and investigate the possibility of artificial seed production by encapsulation of somatic embryos. Linsmeier-Skoog medium was appeared as proper for somatic embryogenesis. Sucrose with $3{\sim}5%$ as carbon sources was good for somatic embryogenesis, and both ammonium and nitrate nitrogen were necesary for normal somatic embryo production. BA with NAA or kinetin with NAA were better than the use of cytokinin alone for both somatic embryogenesis and numbers of somatic embryos. $AgNO_3$ as protectant for vitrification of seedlings in vitro culture had no harmful effect on somatic embryos. Sphericity of encapsulated seeds was good at 3% gel of sodium alginate but germination was better at 2.5% sodium alginate level. Artificial seeds were germinated and developed normal shoots and roots under in vitro condition.

• 한국해양학회지
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• v.25 no.1
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• pp.8-20
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• 1990

A series of pore water data were obtained during the different time over one year period between October 1987 and October 1988, from a site on a muddy intertidal flat, located in the Kyeong-gi Bay, west coast of Korea, The results have revealed that the tidal flat is an environment of active nutrient the subface supplied by the overlying seawater is almost completely removed from the pore water at depth of about 10 cm below the sediment surface. The nutrients such as ammonium and phosphate are produced through this process and subsequently accumulated in the pore water forming steep gradients near the sediment surface. Below the main sulfate redirection zone, a secondary peak of dissolved sulfate was often observed. Greal seasonal variation of the pore water nutrient profiles was observed, which was particularly clear in their maximum concentration as well as in their concentration gradient. The rate constants of sulfate reduction and nutrient regeneration, estimated by using a diagenetic model (Berner, 1980), differ by an order of magnitude between the summer and winter seasons. The difference in sediment temperature may account for most of the calculated variation. The C:N:P ratio, calculated from the pore water nutrient gradients also exhibits a slight seasonal difference. The organic matter being decomposed by sulfate reduction appears to be depleted in depleted in nitrogen, compared to the average marine organic matter.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.2
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• pp.100-104
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• 1989

This study was carried out in order to develop a compound fertilizer for raising rice seedling in trays. A compound fertilizer, a trail product, was manufactured using the major fertilizer sources of ammonium sulfate, diammonium phosphate and potassium chloride in combination with zeolite and glutamic acid fermentation waste. Besides, polyacrylamide for slow release control of the fertilzer and Tachigaren and sulfuric acid for reducing the occurrence of seedling rot were used. The component ratios of N, $P_2O_5$ and $K_2O$ of trial product were 4.19, 5.41 and 4.05 percent respectively. The dissolution rate of nitrogen component in water for the trial product with polyacrylamide was lower about fifteen percents than the product without polyacylamide in six hours. Hymexazole, main component of Thachigaren, from the product was released about 86.2 percents in forty eight hours. When the product with polyacylamide applied on red earth soil and paddy soil, the pH of soil ranged from 4.6 to 5.4 for 25 days experiment.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.311-317
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• 1983

These studies were carried out to investigate the effects of rice straw on the leaching of chemical constituents in paddy soil. Rice plants were cultured in paddy soil to which rice straw was applied and then chemical properties of percolated water were analysed. The results were as follows. The leaching of calcium and magnesium was affected by rice straw application in the early stages of plant growth and by rice root activity in the late stages. The application of the straw promoted the reduction of the soil followed by increasing the leaching of iron and manganese. The leaching of potassium, ammonium-nitrogen and chloride was not due to the application of rice straw and the leaching of carbon dioxide increased with the application of rice straw, at the same time chemical properties seemed to be affected by rice root activity. Generally, cation and anion leached in the percolated water were equivalent. Calcium, magnesium, Fe as cation and $HCO_3$, $SO_4{^{-2}}$ as anion were important constituents in the percolated water from paddy soil.

• KSBB Journal
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• v.8 no.2
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• pp.156-163
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• 1993

Strains degrading ethylene glycol(EG) and terephthalic acid(TPA) were isolated from water systems, and identified as Pseudomonas sp. They were named as Pseudomonas sp. EAW for EG and as Pseudomonas sp. TS2 for TPA. The optimal culture conditions of temperature, pH and nitrogen source were found to be $35^{\circ}C$, 7.5 and ammonium sulfate, respectively. The growth of strains and removal efficiency was slightly promoted by trace elements such as niacin and biotin in case of EG, and by trace elements such as $Na_2MoO_4{\cdot}2H_2O$ and thiamin i case of TPA. With increasing inoculation sloe for batch culture, the removal efficiency of EG by the strain EAW was conspicuously increased, while the removal efficiency of TPA by the strain TS2 was not changed as much as that of EG. The growth rate of the strain EAW was much more decreased than that of the strain TS2 in the enrichment medium, as the frequency of repeated-batch culture in the rich-medium increased. in case of real wastewater, growth rate and removal efficiencies of EG and TPA were lower than those in the enrichment medium. $COD_{Mn}\;and\;COD_{Cr}$ removal efficiencies after 48 hrs batch culture in real wastewater were 89% and 93%, respectively. The specific growth rate was inhibited when the initial concentration of EG or TPA was more than 25g/L.