• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.113-121
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• 1992

An the livestock production in Japan is industrialized, a tremendous amount of animal wastes is being produced annually, resulting in serious environmental pollution problems. Animal wastes could be pollutants, but they are also important sources of fertilizer nutrients and organic matter. Composting is an effective way of promoting the increased utilization of animal wastes. The characterization of maturing process during composting is important in order to improve the composting technology and to develop and efficient method to estimate the degree of maturity. The rise and fall in temperature, and changes in the constituents of the compost, reflect the maturing process and may serve as indicators for maturation. In addition, the detection of nitrate by diphenylamine, the determination of cation-exchange capacity (CEC), and the germination test, are also recommended as the methods of estimating the degree of maturity. The heavy applications of animal manure and compost may cause an adverse effect on soils and crops. When excess manure is applied, the nitrogen will be accumulated in soil, resulting in accumulation of nitrate in crops and pollution of the groundwater. Guidelines for application rates are recommended, to maintain soil productivity and quality of crops, and to prevent the environmental pollution.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1958-1965
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• 2008

A denitrifying polyphosphate-accumulating bacterium (YKP-9) was isolated from activated sludge of a 5-stage biological nutrient removal process with step feed system. This organism was a Gram-negative, coccus-shaped, facultative aerobic chemoorganotroph. It had a respiratory type of metabolism with oxygen, nitrate, and nitrite as terminal electron acceptors. The 16S rRNA gene sequence of strain YKP-9 was most similar to the 16S rRNA gene sequence of Paracoccus sp. OL18 (AY312056) (similarity level, 97%). Denitrifying polyphosphate accumulation by strain YKP-9 was examined under anaerobic-anoxic and anaerobic-oxic batch conditions. It was able to use external carbon sources for polyhydroxyalkanoates(PHA) synthesis and to release phosphate under anaerobic condition. It accumulated polyphosphate and grew a little on energy provided by external carbon sources under anoxic condition, but did neither accumulate polyphosphate nor grow in the absence of external carbon sources under anoxic condition. Cells with intracellular PHA cannot accumulate polyphosphate in the absence of external carbon sources under anoxic condition. Under oxic condition, it grew but could not accumulate polyphosphate with external carbon sources. Based on the results from this study, strain YKP-9 is a new-type denitrifying polyphosphate-accumulating bacterium that accumulates polyphosphate only under anoxic condition, with nitrate and nitrite as the electron acceptors in the presence of external carbon sources.

• Environmental Engineering Research
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• v.25 no.3
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• pp.274-280
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• 2020

The marine sediment sustains from the anoxic condition due to increased nutrients of external sources. The nutrients are liberated from the sediment, which acts as an internal source. In hypoxic environments, anaerobic respiration results in the formation of several reduced matters, such as N₂ and NH₄⁺, N₂O, Fe²⁺, H₂S, etc. The experimental results have shown that nitrogen and sulfur played an influential, notable role in this biogeochemical cycle with expected chemical reductions and a 'diffusive' release of present nutrient components trapped in pore water inside sediment toward the bulk water. Nitate/ammonium, sulfate/sulfides, and ferrous/ferric irons are found to be the key players in these sediment-waters mutual interactions. Organonitrogen and nitrate in the sediment were likely to be converted to a form of ammonium. Reductive nitrogen is called dissimilatory nitrate reduction to ammonium and denitrification. The steady accumulation in the sediment and surplus increases in the overlying waters of ammonium strongly support this hypothesis as well as a diffusive action of the involved chemical species. Sulfate would serve as an essential electron acceptor so as to form acid volatile sulfides in present of Fe³⁺, which ended up as the Fe²⁺ positively with an aid of the residential microbial community.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.222-228
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• 2022

As a possible feedstock for biodiesel, the marine green alga Tetraselmis sp. was cultivated under different conditions of phototrophic, mixotrophic and heterotrophic cultures. Glycerol, a byproduct from biodiesel production process, was used as the carbon source of mixotrophic and heterotrophic culture. The effects of glycerol supply and nitrate-repletion were compared for different trophic conditions. Mixotrophic cultivation exhibited higher biomass productivity than that of phototrophic and heterotrophic cultivation. Maximum lipid productivity of 55.5 mg L^-1 d^-1 was obtained in the mixotrophic culture with 5 g L^-1 of glycerol and 8.8 mM of nitrate due to the enhancement of both biomass and lipid accumulation. The major fatty acid methyl esters (FAME) in the produced biodiesel were palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3). The degree of unsaturation was affected by different culture conditions. The biodiesel properties predicted by correlation equations based on the FAME profiles mostly complied with the specifications from the US, Europe and Korea, with the exception of the cold-filter plugging point (CFPP) criterion of Korea.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.183-190
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• 1992

The influence of various levels of major medium components such as sucrose, nitrate, phosphate, plant growth regulators, and light intensity for cell growth and the production of anthocyanin content in cell cultures of Populus alba ${\times}$ P. glandulosa were investigated. Best results for anthocyanin yield were obtained using Murashige and Skoog(MS) medium containing 5% sucrose, 12.5% nitrate, 200% phosphate, 1.0mg/l indole-3-acetic acid(IAA), 1.0mg/l benaylaminopurine(BAP), and continuous illumination of 7,000 lux. On the other hand, maximum cell growth was achieved with 5% sucrose, 50% nitrate above 400% phosphate compare with that of MS basal mediumi, and 0.5mg/l 2, 4-dichlorophenoxyacetic acid(2, 4-D). Anthocyanin accumulation in a suspension cultured cells of given genotype was stimulated by subculturing onto the medium lacking 2, 4-D. Pigmented cell clusters were extracted with methanol containing 1% hydrochloric acid (HCl) and then anthocyanin was identified by thin layer chromatography (TLC) and U. V. spectrophotometer.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.110-117
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• 2014

Recently microalgae have been proposed as a promising biodiesel feedstock, owing to their higher lipid productivity and non-arable land based cultivation system. Biomass and lipid productivities of microalgae are largely affected by various environmental and nutritional factors. In this study, the effects of nitrogen (nitrate and ammonium) and organic carbon (glucose and glycerol) sources on the cell growth and lipid production of Chlorella sp. KR-1 were examined in flask cultures. Under autotrophic culture conditions for 15 days, overall cell growth and lipid (fatty acid methyl ester, FAME) production with nitrate were better than those of ammonium, resulting in 1.06 g cell/L and 333 mg FAME/L, respectively. Maximal intracellular lipid contents (348 - 352 mg FAME/g cell) were observed at low concentrations of 1 mM for both nitrate and ammonium. In the supply of light, addition of glucose in the range of 1 - 20 g/L showed higher cell densities than the autotrophic cell growth condition. Higher lipid accumulation of 375 mg FAME/g cell could achieved at 5 g glucose/L albeit of relatively short incubation of 7 days. With glycerol, intracellular lipid contents were ~1.9 times lower than glucose cases although similar cell growths were observed for both carbon sources.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.294-299
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• 2000

In order to find out the effects of shading and nitrogen fertilization on the accumulation of $NO_3\;^-$ in leaves of lettuce, lettuce plants were cultivated in the pots under glasshouse condition with different rates of shading(0, 50%) and nitrogen fertilization(100, 180, 200, 300, $400\;kg{\cdot}ha^{-1}$). The pH value was lower in soil after experiment than before experiment, whereas, contents of EC and $NO_3-N$ were higher. As the amounts of nitrogen fertilization were increased, pHs were decreased, but EC and the contents of $NO_3-N$ were increased. At the nitrogen fertilizations of 100, 180, 200, 300 and $400\;kg{\cdot}ha^{-1}$, the germination rates of lettuce were decreased to 84, 78, 76, 72 and 74%, and survival rates were also decreased to 94, 94, 90, 60 and 46%, respectively. However, the fresh weight of lettuce was highest at $45\;g{\cdot}plant^{-1}$ in the recommended fertilizer $plot(180\;kg{\cdot}ha^{-1})$ with non-shading condition. The contents of $NO_3\;^-$ in the leaves of lettuce were increased 2.8-4.1 times under 50% shading conditions than that under non-shading condition. It kept increasing up to seven order of growth phase; however, it started to decrease after eight order phase. Nitrate reductase activity of lettuce in non-shading condition was higher than that in 50% shading condition.

• The Journal of Natural Sciences
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• v.6 no.1
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• pp.49-54
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• 1993

This study was conducted to investigate the influence of various calcium salts on the accumulation of calcium in apple fruits when sprayed on whole tree. Differences in the total calcium contents of fruits were found between calcium sources and cultivars. In 'Tsugaru' , calcium nitrate, calcium chloride, and calcium carbonate were all effective but only calcium chloride and calcium carbonate appeared to be effective in 'Fuji' . Major parts of the applied calcium were accumulated in the feel and outer flesh. Ethylene evolution of fruit was retarded during storage with the increase of total calcium content in 'Fuji' fruit treated calcium acetate.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.35-41
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• 1987

Nitrate nitrogen was absorbed dominantly among the inorganic nitrogen nutrients by tobacco plant. Transport and reduction of $NO_3-N$ in plant tissue were the important metabolism for supplying synthetic N compounds to developing tissues during growth period. Under field and environment-controlled condition tobacco plants were grown and seperated to leaf tissues at stalk positions for investigation of nitrogen transport and assimilation ability during period of rapid vegative growth. The results of studies were summarized as follows: 1. $NO_3-N$ absorbed from roots was transported as inorganic nitrogen through the vascular tissue of leaf veins as resulting from the high $NO_3-N$ ratio of the nitrogen content in leaf veins, but these ratios in mesophyll tissue of the same leaf laminae decreased remarkably in disregard of higher accumulation of nitrogen being compared to midvien. 2. Mesophyll tissue of mature leaves appeared higher value of nitrate reductase activity (NRA) comparing with other tissues, stem, leaf vien, and meristmatic tissue at emergence point with young leaves. 3. Matured leaves at lower position being reducing nitrate nitrogen vigorously observed thick laminae and kept high amount of water in them. 4. Mature leaves of young plant reduced $NO_3-N$ vigorously for supply synthetic N compounds to meristmatic tissues at growing point by the reason of narrow and few leaves at young stage, but in advancing growth period NRA of mature leaves along upper position reached to lower value. This appearence attributed to distribution of organic-N compound demanding for growth to increasing numbers of wide leaves.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1455-1462
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• 2012

The vertical distributions of nitrifying bacteria in aerobic fixed biofilm were investigated to evaluate the relationship between nitrification performance and microbial community at different HRT. Fluorescent in situ hybridization (FISH) and portable ion selective microelectrode system were adopted to analyze microbial communities and ions profiles according to the biofilm depth. Cilia media packed MLE (Modified Ludzack-Ettinger) like reactor composed of anoxic, aerobic I/II was operated with synthetic wastewater having COD 200 mg/L and $NH_4{^+}$-N mg/L at HRT of 6 hrs and 4 hrs. Total biofilm thickness of aerobic I, II reactor at 4 hrs condition was over two times than that of 6 hrs condition due to the sufficient substrate supply at 4 hrs condition (6 hrs; aerobic I 380 ${\mu}m$ and II 400 ${\mu}m$, 4 hrs; aerobic I 830 ${\mu}m$ and II 1040 ${\mu}m$). As deepen the biofilm detection point, the ratio of ammonia oxidizing bacteria (AOB) was decreased while the ratio of nitrite oxidizing bacteria (NOB) was maintained similar distribution at both HRT condition. The ratio of AOB was higher at 4 hrs than 6 hrs condition and $NH_4{^+}$-N removal efficiency was also higher at 4 hrs with 89.2% than 65.4% of 6 hrs. However, the ratio of NOB was decreased when HRT was reduced from 6 hrs to 4 hrs and $NO_2{^-}$-N accumulation was observed at 4 hrs condition. Therefore, it is considered that insufficient HRT condition could supply sufficient substrate and enrichment of AOB in all depth of fixed biofilm but cause decrease of NOB and nitrite accumulation.