• KSBB Journal
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• v.18 no.4
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• pp.249-254
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• 2003

Experiments were carried out to select an industrial nitrogen source and optimize erythritol production by Candida magnoliae in fed-batch culture. Among the industrial nitrogen sources tested, light steep water (LSW) was found to be the best nitrogen source for producing erythritol, based on erythritol yield and raw material price. The maximum erythritol concentration obtained a 131.6 g/L, with a 52.6％ yield and 0.52 g/L-hr productivity from a 250 g/L glucose and 43.3 mL/L LSW in batch culture. Two-stage fed-batch culture was chosen to improve the volumetric productivity and the yield of erythritol. High cell density culture in cell growth stage was achieved by batch type culture containing 100 g/L glucose and 500 mL/L LSW. The cell concentration was 71.0 g/L after 23 hours of culture. Erythritol productivity was decreased by increasing glucose concentration in the production stage. But 37.3％ of the maximum erythritol yield was obtained with 185.5 g/L of erythritol and 1.66 g/L-hr of productivity when 820 g of glucose powder was directly added to a concentration of 450 g/L glucose in production stage.

• Korean Journal of Ichthyology
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• v.25 no.1
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• pp.1-8
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• 2013

Rockfish, Sebastes schlegeli (total length; $10.36{\pm}0.49cm$, total weight; $16.28{\pm}1.86g$, N; 290) were exposed to various concentrations of naphthalene for 28 days. Exposure concentrations of naphthalene established control, ethanol (solvent) control, 0.5, 1.0, 1.5 and 2.0 mg Nap $L^{-1}$. After exposure, We observed survival rate, and degree of tissue change (DTC) in gill under optical microscopy. Survival rate of the rockfish was more than 90% in control, ethanol control, 0.5 and 1.0 mg Nap $L^{-1}$, whereas it decreased in 1.5 and 2.0 mg Nap $L^{-1}$ (respectively 80%, 62.2%). In histological observation of gill, hyperplasia of epithelial cells observed in all exposure groups. But no showed increase of DTC which was related to concentration. Whereas, DTC at fusion of gill lamellar, lamellar telangiectasia, stasis, aneurysm and necrosis showed dose dependent increase. Especially, fusion of gill lamellar, lamellar telangiectasia and stasis observed at more 1.0 mg Nap $L^{-1}$, and aneurysm and necrosis at more 1.5 mg Nap $L^{-1}$. These results showed naphthalene caused survival and severe change to the gill of the rockfish which was related to exposure concentration.

• Microbiology and Biotechnology Letters
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• v.7 no.4
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• pp.205-209
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• 1979

Lactobacillus acidophilus exhibited more growth and produced greater amounts of acid in the soy milk than Streptococcus thermophilus, Lactobacillus bulgaricus, and Lactobacillu helveticus examined. The supplementation of the soy milk with glucose accelerated the growth of L. acidophilus, and enhanced acid production by L. acidophilus whereas sucrose addition was without effect. The supplementation of the soy milk containing five percent glucose with a methionine accelerated the growth of L. acidophilus, and enhannced acid production by L. acidophilus. L. acidophilus showed greater population in the soy milk containing five percent glucose which was treated with 0.0008％ protease (9.40$\times$10$^{8}$ /m/) than the soy milk containing five percent glucose (2.02$\times$10$^{9}$ /ml) moreover L. acidophilus produced greater amounts of acid in the soy milk containing five percent glucose which was treated with 0.0008％ protease (1.47 ％) than in the soy milk containing five percent glucose (0.56％)

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.180-192
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• 2004

This study was carried out to assess the seasonal variation of water quality and the effect of pollutant loading from watershed in a shallow eutrophic reservoir (Shingu reservoir) from November 2002 to February 2004, Stable thermocline which was greater than $1^{\circ}C$ per meter of the water depth formed in May, and low DO concentration (< 2 mg $O_2\;L^{-1}$) was observed in the hypolimnion from May to September, 2003. The ratio of euphotic depth to mixing depth ($Z_{eu}/Z_{m}$) ranged 0.2 ${\sim}$ 1.1, and the depth of the mixed layer exceeded that of the photic layer during study period, except for May when $Z_{eu}$ and $Z_{m}$ were 4 and 4.3 m, respectively. Most of total nitrogen, ranged 1.1 ${\sim}$ 4.5 ${\mu}g\;N\;L^{-1}$, accounted for inorganic nitrogen (Avg, 58.7%), and sharp increase of $NH_3$-N Hand $NO_3$-N was evident during the spring season. TP concentration in the water column ranged 43.9 ${\sim}$ 126.5 ${\mu}g\;P\;L^{-1}$, and the most of TP in the water column accounted for POP (Avg. 80%). During the study period, DIP concentration in the water column was &;lt 10 ${\mu}g\;P\;L^{-1}$ except for July and August when DIP concentration in the hypolimnion was 22.3 and 56.7 ${\mu}g\;P\;L^{-1}$, respectively. Increase of Chl. a concentration observed in July (99 ${\mu}g\;L^{-1}$) and November 2003 (109 ${\mu}g\;L^{-1}$) when P loading through two inflows was high, and showed close relationship with TP concentration (r = 0.55, P< 0.008, n = 22). Mean Chl. a concentration ranged from 13.5 to 84.5 mg $L^{-1}$ in the water column, and the lowest and highest concentration was observed in February 2004 (13.5 ${\pm}$ 1.0 ${\mu}g\;L^{-1}$) and November 2003 (84.5 ${\pm}$29.0 ${\mu}g\;L^{-1}$), respectively. TP concentration in inflow water increased with discharge (r = 0.69, P< 0.001), 40.5% of annual total P loading introduced in 25 July when there was heavy rainfall. Annual total P loading from watershed was 159.0 kg P $yr^{-1}$, and that of DIP loading was 126.3 kg P $yr^{-1}$ (77.7% of TP loading. The loading of TN (5.0ton yr-1) was 30 times higher than that of TP loading (159.0 kg P yr-1), and the 78% of TN was in the form of non-organic nitrogen, 3.9 ton $yr^{-1}$ in mass. P loading in Shingu reservoir was 1.6 g ${\cdot}$ $m^{-2}$ ${\cdot}$ $yr^{-1}$, which passed the excessive critical loading of Vollenweider-OECD critical loading model. The results of this study indicated that P loading from watershed was the major factor to cause eutrophication and temporal variation of water quality in Shingu reservoir Decrease by 71% in TP loading (159 kg $yr^{-1}$) is necessary for the improvement of mesotrophic level. The management of sediment where tine anaerobic condition was evident in summer, thus, the possibility of P release that can be utilized by existing algae, may also be considered.

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.202-211
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• 2010

The variations of physico-chemical factors and the species compositions of phytoplanktons were investigated to analyze the marine ecosystem at the depths during summer in the coast of Dokdo (stations DOK 1-3). The mean values of conductivity (48.9 mS $cm^{-1}$), salinity (32.9 psu) and total suspended solids (57.9 mg $L^{-1}$) were the highest in DOK 1. The biomass (Chl-a) of phytoplanktons was the highest in the surface of DOK 1 (2.61 ${\mu}gL^{-1}$). By the means of physicochemical factors (salinity, turbidity, Chl-a, TN, TP and Si), the water estimated in the coast of Dokdo was more eutrophicated than that in 2008. The phytoplanktons were a total of 42 species in Dokdo, which were composed of 33 species (78.6%) for Bacillariophyceae and 9 species (21.4%) for Dinophyceae. The standing crops of phytoplanktons were the highest ($18{\times}10^3$ cells $L^{-1}$) in the surface of DOK 2 and in the surface of DOK 3, while they were the lowest ($2{\times}10^3$ cells $L^{-1}$) at depth of 40 m of DOK1 and at depth of 30 m of DOK 3. The dominant species of phytoplanktons were Chaetoceros castracanei ($6{\times}10^3$ cells $L^{-1}$) in the surface, Rhizosolenia alata f. gracillima ($3{\times}10^3$ cells $L^{-1}$) at depth of 20 m and Protocentrum compressum ($4{\times}10^3$ cells $L^{-1}$) at the depth of 30 m of DOK 1. At the surface of DOK 2, the dominant species was Bacillaria paxillifer ($6{\times}10^3$ cells $L^{-1}$), while it was Hemiaulus indicus ($12{\times}10^3$ cells $L^{-1}$) at the surface of DOK 3. The DOK 1, which is affected by upwelling, whirlpool and circulation due to the East Korean Warm Current, was the most eutrophicated water body among three stations. The monitoring of marine ecosystem in the coast of Dokdo should be continued to propose the alternatives for water quality and species conservation and to purify the eutrophicated water body due to artificial pollutants as well as natural effectors by the global warming, the climatic change, etc.

• Journal of the Korean Chemical Society
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• v.49 no.1
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• pp.47-55
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.372-373
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.94-95
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• 2000

• Bulletin of the Korean Mathematical Society
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• v.47 no.3
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• pp.527-540
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• 2010

We characterize the boundedness and compactness of the weighted composition operator on the logarithmic Bloch space $\mathcal{L}\ss=\{f{\in}H(D):sup_D(1-|z|^2)ln(\frac{2}{1-|z|})|f'(z)|$<+$\infty$ and the little logarithmic Bloch space ${\mathcal{L}\ss_0$. The results generalize the known corresponding results on the composition operator and the pointwise multiplier on the logarithmic Bloch space ${\mathcal{L}\ss$ and the little logarithmic Bloch space ${\mathcal{L}\ss_0$.

• Journal of the Korean Mathematical Society
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• v.47 no.1
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• pp.29-40
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• 2010

In this paper, we study a generalization of the Banach space B($l_2$) of all bounded linear operators on $l_2$. Over this space, we present some reasonable ways to define Schatten-type classes which are generalizations of the classical Schatten classes of compact operators on $l_2$.