• Korean Journal of Microbiology
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• v.23 no.2
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• pp.84-89
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• 1985

The effect of exogenous phosphate supply on the regulation of phosphate metabolism was investegated during catabolic repression and catabolic derepression in yeast (Saccharomyces uvarum). As the results, when sugar was supplimented in cells cultivated under phosphate free, the growith rate was low but it was capable of cell division. Polyphosphate "B" was accumulated highly in proportion to amount of phosphate added to the medium. Without regard to phosphate supply of the medium, the total amount of polyphospgate was almost similar, although each polyphosphate was turned over. Activities of all phosphatases remained continuousoy high in the cells cultivated in the phosphate free medium. Especially under catabolic repression, the function of polyphosphate system was shown to compensate the ATP/ADP system as phosphate donor, energy source and regulator.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.427-438
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• 1999

Differential growth of Ulva pertusa Kjellman was observed in response to different photon irradiances and seawater. Growth rate of U. pertusa cultivated in the seawater collected from the East Sea was significantly higher than that in the seawater collected from the Yellow Sea. Optimal growth was found at $100{\mu} molm^{-2} s^{-1}$ in both cases. Chlorophyll contents of U. pertusa grown in the east sea water were higher than that cultivated in the west sea water at irradiances lower than $60{\mu} molm^{-2} s^{-1}$. At irradiances higher than $100{\mu} molm^{-2} s^{-1}$, there was no difference in chlorophyll content in between the two different sea waters with tendency that pigmentation decreased with increasing photon irradiances. Nitrate concentration in the west sea water was 2-fold higher than that in the east sea water, while phosphorus concentrations (0.03 ppm) were similar. Concentrations of $Cu^{2+}$ and $Pb^{2+}$ were 0.004 and 0.003 ppm respectively which are far below environmental standard concentrations (0.02 ppm for $Cu^{2+}$ and 0.1 ppm for $Pb^{2+}$). Taking those data into account, we have done laboratory investigations into the effects of inorganic nutrients and heavy metals on U. pertusa. As nitrate concentration increased from 0.5 to 5 ppm, growth rate of U. pertusa increased, but different concentrations of phosphorus did not cause any differential effect. On the other hand, chlorophyll contents increased with increasing phosphorus concentrations. Copper of U. pertusa be toxic decreased the growth and pigmentation as the concentration increased, whereas lead showed no such effect. Concentrations of $Cu^{2+}$ employed in the present study were much higher than those in ambient seawater. Intermittent soaring of $Cu^{2+}$ level as observed in natural seawater could, however, seriously damage the growth behaviour of U. pertusa.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.232-242
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• 2014

We investigated the interspecific competition between the harmful dinoflagellate Cochlodinium polykrikoides and diatom Skeletonema sp. based on the utilization and uptake of dissolved organic nutrients. C. polykrikoides and S. costatum were able to grow using dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) as well as dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP). This result indicates that the utilization of dissolved organic nutrients may play a role in surviving strategy in the DIN or DIP-limited environments. The half-saturation constants (Ks) of urea and glycerophosphate (glycero-P) calculated from uptake kinetics experiment of C. polykrikoides was lower than those of Skeletonema sp. This result indicates that Skeletonema sp. have higher affinity for dissolved organic nutrients, such as urea and glycero-P, than C. polykrikoides. Although Skeletonema sp. have higher affinity of dissolved organic nutrients, C. polykrikoides could effectively uptake for urea and glycero-P at sub-saturating nutrient concentrations (${\alpha}$ (${\rho}_{max}/Ks$) of C. polykrikoides was higher than Skeletonema sp.. Therefore, C. polykrikoides by utilization and effectively uptake of dissolved organic nutrients under monoculture may have an advantageous position in the interspecific competition with Skeletonema sp. in the low nutrient environments.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.779-785
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• 1994

The interaction between the cationic dye, thionin(Th) and the anionic surfactant, sodium dodecyl sulfate (SDS) has been investigated by absorption spectra. As the temperature of surfactant solution was increased in premicellar range(S/D=10, 80, and 160) which was much lower than the critical micelle concentration(CMC), the increment or decrement of the molar extinction coeffecient ratio appeared. It was found that the most stable temperature range of the oligomer aggregate in Th-SDS system at S/D=160 was below $60^{\circ}C$. With increasing the concentration of inorganic salt and organic solvents in Th-SDS system, ${\alpha}$-band was increased, but ${\gamma}$=band or J-band was decreased. The orders of ${\alpha}$-band increasing power were $Cl^-$>$ClO{_4}{^-}$>$SO{_4}{^{2-}}$>$NO{_3}{^-}$ and 2-propanol>ethanol>methanol>ethylene glycol.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.171-175
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• 1999

We examined the effects of various basal media and exogenous auxins on the growth and saikosaponin production in hairy root cultures of Bupleurum falcatum. Of the various media tested, 2RCM medium was superior for growth and saikosaponin content, in which saikosaponin a, c, and d was produced, however MS medium was resulted in extremely low level in saikosaponin production. By the treatment of 0.5 mg/L IBA the growth rate was increased by about 60% in 2RCM medium, whereas both IAA and IBA showed a potent inhibition effect in saikosaponin biosynthesis by the treatment of 0.01 mg/L~5mg/L.

• Journal of Aquaculture
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• v.16 no.1
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• pp.15-23
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• 2003

We have investigated water quality of the coastal saline groundwaters utilized for fish farms in Jeju Island. The water quality investigation included the spatial observations for 75 fish farms during March-May, 1994 and the hi-monthly observations for both coastal saline groundwaters and seawaters at four fish farms from August 1994 to December 1995. Water temperature of the saline groundwaters ranged from 16 to 18$^{\circ}C$ over the study period. Salinity of the saline groundwaters varied between 20.60 ppt and 34.02 ppt, slightly lower than that of the coastal seawaters(26.47~34.53 ppt). This salinity variation must be associated with local precipitation conditions in Jeju Island. The oxygen saturation for most saline groundwater samples was lower than 80%, ranging from 24.7 to 89.8%. The COD and pH values for the saline groundwaters were similar to those for the coastal seawaters. The concentrations of DIP for the saline groundwaters varied between 0.021 mg/L and 0.121 mg/ L, and seasonal variation of DIP in the saline groundwater ranged from 0.014 to 0.077 mg/L, which were higher than that of the coastal seawaters(0.000~0.015 mg/L). Nitrate in the saline groundwaters accounted for more than 90% of the DIM. The maximum concentrations of ammonia, nitrite, nitrate and DIN in the saline groundwaters were 0.085, 0.012, 2.294 and 2.309 mg/L, respectively. These concentrations of the saline groundwaters were considerably lower than those affected culture organisms. Overall, the saline groundwaters utilized for fish farms in Jeju Island appear to maintain good waterquality for fish farms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.113-118
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• 2016

This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of $0.8dS\;m^{-1}$, $1.6dS\;m^{-1}$, $3.2dS\;m^{-1}$ and $4.8dS\;m^{-1}$. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of $1.6dS\;m^{-1}$, 36.9% in of $3.2dS\;m^{-1}$, and 50.7% in EC of $4.8dS\;m^{-1}$. Root dry matter decreased to 35.8% in EC of $3.2dS\;m^{-1}$, and to 40.5% in EC of $4.8dS\;m^{-1}$. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, $P_2O_5$, $K_2O$ and, MgO in soils of different salinity. On the other hand, $Na_2O$ content was higher in the order roots> shoots> seed, and in the case of roots, $Na_2O$ content increased to 1.02% in soil salinity of $4.8dS\;m^{-1}$. However, up to soil salinity of $1.6dS\;m^{-1}$, the $Na_2O$ content of the seed was similar to that in plant grown in the Control conditions($0.8dS\;m^{-1}$). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately $1.6dS\;m^{-1}$, and seed produced from reclaimedland would be suitable for human consumption.

• Journal of Nutrition and Health
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• v.36 no.7
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• pp.711-719
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• 2003

The effects of taurine, carnitine or glutamine supplementation on endurance exercise performance along with related fatigue factors were evaluated in male college students in the Department of Physical Education, who's maximal oxygen consumption rates (VO$_2$max) were equivalent to those of endurance athletes. Twenty four subjects were randomly divided into 4 groups (n=6), and given placebo, taurine (4 g/day), carnitine (4 g/day), or glutamine (4 g/day) tablets for 2 weeks. Subjects could run 6.9 min or 9.0 min longer until exhausted on a treadmill at the intensity of 75% VO$_2$max following taurine or camitine supplementation for 2 weeks, respectively, compared to the value measured prior to each supplementation. Glutamine or placebo supplementation did not improve the endurance exercise performance based on the running time until exhausted on a treadmill. Serum lactate concentrations measured 1 hr after the initiation of the endurance exercise, as well as at all-out state tended to be decreased by taurine, carnitine, or glutamine supplementation, and were significantly lowered (43% decrease) by carnitine supplementation (p < 0.05). Taurine supplementation significantly reduced the serum inorganic phosphorus concentration measured at all-out state (14% decrease, p < 0.05), while carnitine supplementation significantly lowered the resting state serum inorganic phosphorus level (20% decrease, p < 0.05). Taurine (32% reduction) or carnitine (23% reduction) supplementation significantly decreased serum ammonia concentration measured at all-out state (p < 0.05). From these results, 4 g/day of taurine or carnitine supplementation appears to improve the endurance exercise performance and related human fatigue factors.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1974.06a
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• pp.124.2-124
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• 1974

전보에서 분리ㆍ등정한 섬유소 분해력이 강한 세균을 이용하여 볏짚에서 단세포단백을 생산할 목적으로 각종 알카리에 의한 볏짚의 전처리 효과를 살펴보았다. 즉, 규정농도의 알카리 용액에 24시간 실온에서 침지하여 중성이 될때까지 수세하고 건조시켜 무기염 용액에 4％첨가하여 5일간 진탕 배양한 후 균체량 증가 및 기질의 감소를 측정하여 다음과 같은 결과를 얻었다.(중략)

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.229-233
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• 2016

In this study, an efficient ultrasound-assisted liquid-liquid extraction process was developed for recovering of paclitaxel from plant cell cultures. The optimal ultrasonic power and operating time were 250 W and 15 min at fixed ratio of bottom phase, methylene chloride to top phase, MeOH (25%, v/v). Under the optimal conditions developed in the present method, most of the paclitaxel (~92%) was recovered from crude extract by a single extraction step. Due to the synergistic effect of ultrasound by the addition of inorganic salt, an appropriate inorganic salt concentration and the ultrasonic power were found to be required for the effective recovery of paclitaxel using ultrasound-assisted liquid-liquid extraction.