• Journal of Applied Biological Chemistry
• /
• v.54 no.2
• /
• pp.79-83
• /
• 2011

Over-application of nitrogen fertilizer keeps increasing the salinity in the soils of greenhouse in domestic agriculture. In order to remove the excess amounts of soil nitrate, soil microorganisms which have high capacity of nitrate uptake were isolated from the upland soils and their nitrate uptake activities were measured. Strain GS2 was able to remove 50 mM nitrate within 12 h. After sequence comparison analysis of 16S rRNA gene, the strain was identified and named as Bacillus sp. GS2. When the growth and nitrate uptake activities were measured, maximal values were obtained at $30-40^{\circ}C$ and $37^{\circ}C$, respectively; however, both were optimal at pH 6-8. In the media containing 50 mM nitrate, Bacillus sp. GS2 removed 43 mM nitrate which is corresponding to 86% removal. Similar amounts of nitrate removal were observed at the nitrate concentrations up to 300 mM, showing a saturation in nitrate uptake at concentrations above 50 mM. These results imply that Bacillus sp. GS2 can be a good candidate for the microbial remediation of accumulated environmental nitrate because of its excellent growth and nitrate uptake activity.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.1
• /
• pp.22-27
• /
• 2005

To find out the optimum mixture ratio of ammonium and nitrate on rice plant, 4 rice varieties were examined during 14days after transplanting in hydroponics with the different ratio of ammonium to nitrate(100 : 0, 75: 25,50: 50, 25: 75 and 0: 100). The highest N uptake from solution and the maximum plant dry weight were $60\~70\%$ ammonium and $30\~40\%$ nitrate mixture treatment both in Japonica and Tongil type rice plants. And with the same varieties N-uptake and N use-efficiency were compared between 10.0 mM and 1.0 mM nitrogen using $70\%$ ammonium and $30\%$ nitrate for 24 days after transplanting. Rice plants absorbed more nitrogen$(131\~145\%)$ in 10.0mM than 1.0mM treatment but accumulated N in rice plants were almost the same in both treatment. Among the tested rice cultivars, dry matter production and total accumulative nitrogen in rice plants were much high in Tongil type than japonica type rice cultivars. N-recovery ratios of rice plants from uptake N were $90.8-99.0\%$ in low concentration N solution(1.0 mM), but $69.4-81.7\%$ were observed in high concentration N solution(10.0 mM). It means that suppling low concentration N steadily will be better to prevent loss of N without reducing of growth in rice plants.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.37 no.1
• /
• pp.57-64
• /
• 2004

Effects of light and temperature on the nitrate uptake and germling growth of Enteromorpha compressa (L.) Greville (Chlorophyta) were studied based on samples from Cheongsapo near Busan, Korea. In addition, their effects on fatty acids composition in thallus were examined. Nitrate uptake showed saturation kinetics. $V_{max}$ (maximal uptake rate) and its $K_s$ (half-saturation constant) at $20^{\circ}C,\;80\;{\mu}mol\;m^{-2}s^{-1},$ white light were $1.571\;{\mu}mol{\cdot}g\;fr\;wt^{-1}{\cdot}h^{-1}$ and 3.56 ${\mu}M$, respectively. In nitrate uptake with irradiance, wavelength and temperature, its rate represented respectively the highest value as $1.405\pm0.020,\;0.623\pm0.040,\;1.422\pm0.022\;{\mu}mol{\cdot}g\;fr\;wt^{-1}{\cdot}h^{-1}\;at\;100\;{\mu}mol\;m^{-2}s^{-1},$ red light, $20^{\circ}C$ and exhibited significant difference among the examined conditions (p<0.001). Germling growth of E. compressa also showed saturation kinetics, and $V_{max}$ and its $K_s$ value at $20^{\circ}C,\;100\;{\mu}mol\;m^{-2}s^{-1},$ 12:12 h were $56.18\%\;day^{-1}$ and 0.33 ${\mu}M$, respectively. SGR (specific growth rate) recorded a maximal value as 49.33-54.80, 39.07-50.72, $47.20-54.53\%\;dat^{-1}$ at $120\;{\mu}mol\;m^{-2}s^{-1},$ blue light and $18^{\circ}C$ respectively, and showed significant difference (p<0.001). Red light made the effective nitrate uptake, but germling growth was largely limited by the light. In fatty acids analysis, PUFAs (polyunsaturated fatty acids) were high at blue light, $18^{\circ}C,\;100\;{\mu}M\;NO_3^-.$ However, irradiance did not affect the production of PUFAs. In conclusion, nitrate uptake and germling growth of E. compressa showed saturation kinetics to external nitrate concentration, and were significantly affected by irradiance, wave length and temperature. Fatty acid composition was also influenced by the factors except for irradiance. Their maximal values, together with the highest production of PUFAs, were found at blue light band, $20^{\circ}C,\;100\;{\mu}mol\;m^{-2}s^{-1},\;and\;100\;{\mu}M\;NO_3^-.$

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.5
• /
• pp.782-793
• /
• 1997

To study the physiological adaptation (shift-up) of phytoplankton under the simulated upwelling conditions, nitrate uptake capacity of Dunaliella tertiolecta batch culture was measured in the laboratory using the stable isotope $^{15}N-KNO_3$. Contrary to the expected, there was no significant relationship between the maximum $V_{NO3}$ (nitrogen specific nitrate uptake rate) and the initial nitrate concentration. However, there was a strong relationship between the maximum $\rho_{NO3}$ (nitrate transport rate) and the initial nitrate concentration of $<25\;{\mu}M$, which was also influenced by the physiological status of the culture. The increase in $V_{NO3}$ was mainly due to the increase in PON (particulate organic nitrogen) concentration and partly due to the increase in $V_{NO3}$. When the phytoplankton population was severely shifted-down, the physiological adaptation of nitrate uptake was significantly inhibited at high initial nitrate concentrations. The timing of the maximum $V_{NO3}$ or $\rho_{NO3}$ was related to the initial nitrate concentration. At higher initial nitrate concentrations, maxima in $V_{NO3}$ and $\rho_{NO3}$ occurred 1 or 2 days later than at lower nitrate concentrations. This relationship was the opposite to the prediction from the shift-up model of Zimmerman et al. (1987), The shift-up process is apparently controlled by an internal time sequence and the initial nitrate concentration, but the magnitude of $V_{NO3}$ was affected little by changes in nitrate concentration.

• Journal of Applied Biological Chemistry
• /
• v.56 no.4
• /
• pp.241-244
• /
• 2013

Nitrate is one of the major nutrients in plants, and nitrate fertilizer often overused for the high yields of crops. Nitrate deposit in soil became one of the major reasons causing salt stress. Specially, salt stress is a serious problem in the soils of plastic film or glass houses. In this study, six microorganisms have been isolated from the wet soils near the disposals of livestock farms and their nitrate uptake activities were investigated. These bacteria were able to remove nitrate as high as 1,000-3,000 ppm (10-50 mM). The strain PCE3 showed the highest nitrate uptake activity and it removed more than 3,700 ppm. In order to identify these bacteria, genes of 16S rRNA were sequenced and analyzed. Phylogenetic trees were constructed with the neighbor-joining methods. Among these bacteria, strain PCE3 was identified as Bacillus species. When the growth and nitrate uptake activities were measured, both were maximal at $37^{\circ}C$ and optimal pH was pH 7-9. Bacillus sp. PCE3 removed nitrate up to 40-60 mM (2,500-3,700 ppm) depending on the nitrate concentration in media. Therefore, Bacillus sp. PCE3 can be a good candidate for the microbial remediation of nitrate-deposited soils in glass and plastic film houses.

• KSBB Journal
• /
• v.25 no.1
• /
• pp.62-66
• /
• 2010

This study was carried out to get phosphorus uptake rate in aerobic condition with nitrate and nitrite. Nitrate and nitrite inhibited phosphorus accumulating organisms' (PAOs') luxury uptake in aerobic condition. Nitrite awfully decreased the phosphorus uptake rate in aerobic condition. At the influent of 10 mg ${NO_3}^-$-NL, the phosphorus uptake was decreased to 52% comparing that at no influent of nitrate. And at the influent of 10 mg ${NO_2}^-$-NL, the phosphorus uptake was decreased to 28% comparing that at no influent of nitrite. At the influent of 20 mg ${NO_3}^-$-NL, nitrite and nitrate were co-existed and the phosphorus uptake rate was decreased to 16% comparing that at no influent of nitrite and nitrate. Also, the denitrification was occurred by denitrifying glycogen accumulating organisms (DGAOs)/denitrifying phosphorus accumulating organisms (OPAOs) in spite of aerobic condition, and the phosphorus uptake rate was increased by the decrease of influent nitrate concentration at the aerobic condition. The inflection point in the phosphorus uptake rate was shown at the nitrite concentration of 1.5~2 mg/L.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.4
• /
• pp.265-274
• /
• 2000

To investigate the effects of anion replacement on NO3- concentration in Italian ryegrass. Plants weregrown hydroponically to the full vegetative stage. NO3 supply(control) was replaced with SO1- (Tl), C1-(T2) and water (T3) to during 14 days. The determination of inorganic nutrient uptake and quantification ofprincipal metabolites (nitrate. protein and sugar) followed. Relatively high uptake of ~ a a'n d Ca" for controlplants, K+ and POJ- for T2 plants, and C 1 for TI plants was observed, respectively. Proteins in shoot andstubble were relatively higher in control and TI plants, which coupled N source. In root proteins largelydecreased (especially in T3 plants) during experimental period. Sugars in shoot of all four treatments tendedto decrease during the first 7 days and recovered afterward. Sugars in stubble also markedly decreased duringthe first 7 days, while those in root was much less varied during experimental period. After 14 days oftreatment, nitrate concentration in shoot of control plants was 13mgIg FW. Comparing to control: nitrate inshoot reduced by 27%, 46% and 50% in TI, T2 and T3 plants, respectively. Dry weight was slightlyincreased or not significantly changed in control, T1 and T2 plants, while a significant decrease(31.3% ofcontrol) occurred in T3 plants.(Key words : Italian ryegrass, Anion replacement, Ion uptake, Protein, Sugar, Nitrate)ptake, Protein, Sugar, Nitrate)

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.7 no.3
• /
• pp.146-152
• /
• 1987

Sorghum cv. Pioneer 93 1, sorghum-sudangrass hybrid cv. Sioux and maize plant cv. Blizzard were assayed for toxic concentrations of nitrate-nitrogen ($NO_3$-N) and their relationship to morphological characteristics and environmental temperature in a field and phytotron trial. In the phytotron, sorghum and maize plants ranging from emergence to heading stage, were grown under different day/night temperatures of 30125, 25/20,28/18 and 1818 degree C. Nitrate-nitrogen in sorghum and maize plants was accumulated mainly in stems. Therefore nitrate concentration in the young plants was increased as development of stalks advanced and was highest at the stage of 3-4 leaves, when the plants had a leaf weight ratio 0.78-0.80 g/g plant weight. However, nitrate concentrations of the plant decreased as morphological development progressed, especially from the stage of growing point differentiation. Correlation coefficients showed a positive correlation of nitrate concentration with leaf weight ratio, leaf area ratio and specific leaf area, while plant height, dry matter percentage and absolute growth rate showed a negative association with TEX>$NO_3$-N ($P{\le}0.1$%). Cyanogenic glycosides, total nitrogen and crude protein were close associated with nitrate accumulation, and positively significant ($P{\le}0.1$%). High temperature over 30/25^{\circ}C.$ for 3 weeks increased N-uptake and dry matter accumulation, but reduced nitrate concentration. Under cold temperature below 18/8^{\circ}C.$ concentration of nitrate-N was increased in spite of its limited nitrogen uptake and plant growth.

• Journal of Microbiology and Biotechnology
• /
• v.2 no.4
• /
• pp.255-259
• /
• 1992

The effect of nitrate, nitrite and ammonia as inorganic nitrogen sources on the modulation of nitrogen metabolism of Botryococcus braunii UTEX.-572 has been studied under aeration. The primary process in the regulation of nitrogen metabolism by this alga has the nitrate uptake system. This uptake of nitrate operation was immediately inhibited by the presence of 0.5 mM of ammonium and reversed by 0.2∼0.3 mM ammonium. When cell were exposed to 5 mM of ammonium for 24 hours the activity of nitrate reductase became inactive.

• Journal of Plant Biology
• /
• v.34 no.4
• /
• pp.253-260
• /
• 1991

Spirodela polyrhiza and Lemna aequinoctialis often occurred at the sites of high ammonium concentration and at the sites of high nitrate concentration, respectively. We investigated the different distribution between two species in relation to the type of nitrogen sources and their concentrations. Our experiments showed that L. aequinoctialis grew faster than S. polyrhiza in nitrate media with lower than 15 mM concentration. The nitrate uptake was also faster in L. aequinoctialis than in S. polyrhiza. However, neither differences in growth nor in uptake patterns between these two species were observed in ammonium media. Glutamine synthetase (GS), glutamate dehydrogenase (GDH) and glutamate synthetase (GOGAT) activities were higher in L. aequinoctialis. In particular, nitrate reductase activity (NRA) in L. aequinoctialis was 12.1 times as high as that in S. polyrhiza. These results showed that the two species responded varyingly to the types of nitrogen sources and their concentrations. Therefore, the difference in geographic distribution between the two species appeared to reflect the interspecific differences in enzyme activities and, subsequently, nitrogen absorption abilities.