• Microbiology and Biotechnology Letters
• /
• v.34 no.2
• /
• pp.166-173
• /
• 2006

This research has been performed to clarify the relationship between hydrogeochemistry and bacterial community structure in groundwater contaminated with landfill leachate. We collected and analyzed samples from 5 sites such as leachate (KSG1-12), treated leachate (KSG1-16), two contaminated groundwaters (KSG1-07 and KSG1-08) and non-contaminated groundwater (KSG1-13). pH was 8.83, 8.04, 6.87, 6.87 and 6.53 in order; redox potential (Eh) 108, 202, 47, 200 and 154 mV; electric conductivity (EC) 3710, 894, 1223, 559 and 169.9 $\mu$S/cm; suspended solids (SS) 86.45, 13.74, 4.18, 0.24 and 11.91 mg/L. In KSG01-12, the ion concentrations were higher especially in $Cl^-$ and $HCO_3^-$ than other sites. The concentrations of Fe, Mn and $SO_4^{2-}$ were higher In KSG1-07 than in KSG1-08, and vise versa in $NO_3^{2-}$. In the comparison of DGGE fingerprint patterns, the similarity was highest between KSG1-13 and KSG1-16 (57.2%), probably due to common properties like low or none contaminant concentrations. Otherwise KSG1-08 showed lowest similarities with KSG1-13 (25.8%) and KSG1-12 (27.6%), maybe because of the degree of contamination. The most dominant bacterial species in each site were involved in $\alpha$-Proteobacteria (55.6%) in KSG1-12, $\gamma$-Proteobacteria (50.0%) in KSG1-16, $\beta$-Proteobacteria (66.7%) in KSG1-07, $\gamma$-Proteobacteria (54.5%) in KSG1-08 and $\beta$-Proteobacteria (36.4%) in KSG1-13. These results indicate that the microbial community structure might be changed according to the flow of leachate in grounderwater, implying changes in concentrations of pollutants, available electron accepters and/or other environmental conditions.

• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.2
• /
• pp.131-138
• /
• 1987

Experimental informations on the possible alternative resources of soil addition in sandy paddy soils were obtained by applying fertilizer N, P, and K to the top of 26 cm long columns containing the soil-ameliorator mixture and by determining the concentration and leaching loss of nutrients in percolated water and permeability. 1. Addition of red earth and compost to soils decreased pronouncedly the permeability. Relative magnitude of permeability was compost+slag+red earth > compost+red earth > compost > red earth > compost+slag > slag > non-added soil. 2. Concentration and leaching loss of $NH_4-N$ and $SiO_2$ were high by addition of compost-slag or red earth mixture to soils. The present of these nutrients in soils after experiment was, also, higher than that in non-added soil and in red earth to soils. 3. Those of K, Ca, and Mg were similar to $NH_4-N$ and $SiO_2$. Especially, leaching loss and present of K in soils by addition of compost to soils were higher dramatically than those of non-added soil and of red earth to soils. 4. Those of $Fe^{{+}{+}}$ in non-added soil were much higher than those by addition of compost and slag to soils. These values were the highest in 12 days after submergence, while these of $Mn^{{+}{+}}$ the lowest. 5. Concentration of $NH_4-N$ was high by addition of compost to soils, while the present of it in soils after experiment was tended to be contrary.

• The Korean Journal of Pharmacology
• /
• v.24 no.2
• /
• pp.179-187
• /
• 1988

Verapamil, tetrodotoxin and tetraethylammonium chloride in the stated amount did not affect the $Na^{++}$ induced $Ca^{++}$ release. $Cd^{++}$ and $Zn^{++}$ significantly inhibited the $Na^{++}$ induced $Ca^{++}$ release. $Mn^{++}$ also inhibited $Na^+-Ca^{++}$ exchange. $Cd^{++}$ inhibited $Na^+-Ca^{++}$ exchange noncompetitively with an apparent inhibition constant (Ki) of $100\;{\mu}M$. $Cd^{++}$ caused loss of sulfhydryl group, whereas $Zn^{++}$ did not show any significant effect. $Cd^{++}$ and $Zn^{++}$ effectively inhibited $Na^+-Ca^{++}$ ATPase and slightly inhibited $Ca^{++}-Mg^{++}$ ATPase. Carbonyl cyanide chlorophenylhydrazone, 2,4-dinitrophenol and sodium arsenate stimulated the $Na^{++}$ induced $Ca^{++}$ release. Dibucaine and oligomycin slightly inhibited it. The results suggest that the $Na^+-Ca^{++}$ exchange on the synaptosomal plasma membrane may be not accomplished by ion channels. The $Na^+-Ca^{++}$ exchange is sensitively inhibited by $Cd^{++}$ and this transport process appears to be partially regulated by sulfhydryl groups of the synaptosomal plasma membrane. It is also postulated that $Na^+-Ca^{++}$ exchange is suppressed during the phosphorylation reaction of protein component on the neuronal membrane.

• Economic and Environmental Geology
• /
• v.35 no.1
• /
• pp.13-23
• /
• 2002

The chemical compositions of groundwaters from the granite areas mainly belong to Ca-HC0$_{3}$ and Na-HC0$_{3}$type, and some of these belong to Ca-(CI+S0$_{4}$) and Na-(CI+S0$_{4}$) type. Spring waters and groundwaters from anorthosite areas belong to Ca-HC03 and Na-HC03 type, respectively. The result of reaction path modeling shows that the chemical compositions of aqueous solution reacted with granite evolve from initial Ca-CI type, via CaHC0$_{3}$ type, to Na-HC0$_{3}$ type. The result of rain water-anorthosite interaction is similar to evolution path of granite reaction and both of these results agree well with the field data. In the reaction path modeling of rain watergranite/anorthosite reaction, as a reaction is progressing, the activity of hydrogen ion decreases (pH increases). The concentrations of cations are controlled by the dissolution of rock-forming minerals and precipitation and re-dissolution of secondary minerals according to the pH. The continuous addition of granite causes the formation of secondary minerals in the following sequence; gibbsite plus hematite, Mn-oxide, kaolinite, silica, chlorite, muscovite (a proxy for illite here), calcite, laumontite, prehnite, and finally analcime. In the anorthosite reaction, the order of precipitation of secondary minerals is the same as with granite reaction except that there is no silica precipitation and paragonite precipitates instead of analcime. The silica and kaolinite are predominant minerals in the granite and anorthosite reactions, respectively. Total quantities of secondary minerals in the anorthosite reaction are more abundant than those in the granite reaction.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.119-120
• /
• 2004

Urban groundwater has a unique hydrologic system because of the complex surface and subsurface infrastructures such as deep foundation of many high buildings, subway systems, and sewers and public water supply systems. It generally has been considered that increased surface impermeability reduces the amount of groundwater recharge. On the other hand, leaks from sewers and public water supply systems may generate the large amounts of recharges. All of these urban facilities also may change the groundwater quality by the recharge of a myriad of contaminants. This study was performed to determine the factors controlling the recharge of deep groundwater in an urban area, based on the hydrogeochemical characteristics. The term ‘contamination’ in this study means any kind of inflow of shallow groundwater regardless of clean or contaminated. For this study, urban groundwater samples were collected from a total of 310 preexisting wells with the depth over 100 m. Random sampling method was used to select the wells for this study. Major cations together with Si, Al, Fe, Pb, Hg and Mn were analyzed by ICP-AES, and Cl, N $O_3$, N $H_4$, F, Br, S $O_4$and P $O_4$ were analyzed by IC. There are two groups of groundwater, based on hydrochemical characteristics. The first group is distributed broadly from Ca-HC $O_3$ type to Ca-C1+N $O_3$ type; the other group is the Na+K-HC $O_3$ type. The latter group is considered to represent the baseline quality of deep groundwater in the study area. Using the major ions data for the Na+K-HC $O_3$ type water, we evaluated the extent of groundwater contamination, assuming that if subtract the baseline composition from acquired data for a specific water, the remaining concentrations may indicate the degree of contamination. The remainder of each solute for each sample was simply averaged. The results showed that both Ca and HC $O_3$ represent the typical solutes which are quite enriched in urban groundwater. In particular, the P$CO_2$ values calculated using PHREEQC (version 2.8) showed a correlation with the concentrations of maior inorganic components (Na, Mg, Ca, N $O_3$, S $O_4$, etc.). The p$CO_2$ values for the first group waters widely ranged between about 10$^{-3.0}$ atm to 10$^{-1.0}$ atm and differed from those of the background water samples belonging to the Na+K-HC $O_3$ type (<10$^{-3.5}$ atm). Considering that the p$CO_2$ of soil water (near 10$^{-1.5}$ atm), this indicates that inflow of shallow water is very significant in deep groundwaters in the study area. Furthermore, the P$CO_2$ values can be used as an effective parameter to estimate the relative recharge of shallow water and thus the contamination susceptibility. The results of our present study suggest that down to considerable depth, urban groundwater in crystalline aquifer may be considerably affected by the recharge of shallow water (and pollutants) from an adjacent area. We also suggest that for such evaluation, careful examination of systematically collected hydrochemical data is requisite as an effective tool, in addition to hydrologic and hydrogeologic interpretation.ion.ion.

• Microbiology and Biotechnology Letters
• /
• v.7 no.3
• /
• pp.135-140
• /
• 1979

A Streptomyces sp. strain AS-727 which was capable of producing penicillinase, was isolated from soil. The enzyme production was affected by the carbon and nitrogen sources added. Among them so far tested, glucose (or maltose) and sodium nitrate increased the enzyme production. And the amount of enzyme prodced reached maximum in 4 days cultivation. The optimla pH and temperature of the penicillinase was between pH 6.0 to 8.0 and 4$0^{\circ}C$ respectively. The stabel pH range of the enzyme was stable at 4$0^{\circ}C$, but it lost about 30％ and 40％ of the the activity respectively when it was treated at 6$0^{\circ}C$ and 8$0^{\circ}C$ for 60 minutes. The activity of the enzyme was inhibited by Z $n^{++}$, but A $g^{+}$, $Co^{++}$, $_Mn^{++}$, $Ca^{++}$, P $b^{++}$ did not affected enzyme activity. Peculiarly, the enzyme protein precipitated by freezing or addition of ammonium sulfate, urea, sodium chloride and some organic solvents as etanol, methanol, acetone was not dissolved in deionized water or any buffer solution.n.n.ion.n.n.

• Korean Journal of Microbiology
• /
• v.35 no.2
• /
• pp.133-138
• /
• 1999

Essential amino acids involving in the active site ofthe cytidn~e deruninase from Bncillus subtilis ED 213 were determined by chemical modification studies. Tllc purified cytidine deruninase tiom Booillus subtilis ED 213 required the reduced form of Fe(lI)ion. since the enzyme was inhibited 43% by 1 mnM o-phenanthroline. Whereas the enzyme activity was activated up to 28% by 1 1 ethylenediaminetetraacetic acid. The cytidine deaninase activily was completely inhibited by 1 mM N-bromosuccinimide, chloramine-T, and p-chloromercuribenzoic acid (p-CMB), respectively. The enzyme activity was inhibited 36% by 1 mM pyridoxal-S-phosphale, and 31% by 1 mM l-ethy~-3-(3-dirneIhj~laminoprop}~~)c~bodiiamide and glycine inethyl ester. The enzyme activity was strongly inhibited 68% by 1 \mu$M \rho$-CMB and this inhibition of the enzyme activity with 1 \mu$M \rho$-CMB was completely reactivated by 5 mM cysleine as a reducing agent. We speculaled that tyrosine, methionine, cysteuie and/or serine residues are located ui or near ihe active site of the cytidine deruniuase from Bncilus subrilis ED 213 and indirectly related to lysine and/or glycine.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.4
• /
• pp.252-257
• /
• 2001

To get the basic information for the water quality improvement and control of water resource at Mankyeong river stream, the water quality in four site of main stream and three site of branch stream at the upper stream were investigated mainly from February to August in 2000. The water temperature was affected by depth, flow rate of the water, and air temperature, and ranged 6.4 to $30.8^{\circ}C$. The pH, DO and BOD values of the water was $5.9{\sim}9.7$, $4.6{\sim}14.50\;mg/L$, and $0.1{\sim}11.8\;mg/L$ range, respectively. The content of total nitrogen, $NO_3-N$ and $NH_4-N$ was $1.19{\sim}10.61\;mg/L$, $1.00{\sim}5.93\;mg/L$, and ND $(non\;detected){\sim}2.79$ mg/L, respectively. The concentration of total phosphorus was ND to 1.14 mg/L. The concentration of Cl ion was $3.5{\sim}196.4\;mg/L$. The content of Fe and Mn was $0.002{\sim}0.100\;mg/L$ and $ND{\sim}0.04\;mg/L$, respectively. The contents of heavy metal Cd, Cu, and Zn were $ND{\sim}0.03\;mg/L$, $ND{\sim}0.05\;mg/L$, and $0.001{\sim}0.17\;mg/L$, respectively. Pb was not detected in all the samples. The pH, total nitrogen contents, and total phosphorus content were frequently exceeded the water quality standard for agriculture. The degree of water pollution was very varied by the sampling place. The water quality was generally polluted in the dry season more than in rainy season. The highest level of water pollution observed in the area of Samyea Bridge among the 7 sites.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.5
• /
• pp.785-792
• /
• 2020

ʟ-Theanine, found in green tea leaves has been shown to positively affect immunity and relaxation in humans. There have been many attempts to produce ʟ-theanine through enzymatic synthesis to overcome the limitations of traditional methods. Among the many genes coding for enzymes in the ʟ-theanine biosynthesis, glutamylmethylamide synthetase (GMAS) exhibits the greatest possibility of producing large amounts of production. Thus, GMAS from Methylovorus mays No. 9 was overexpressed in several strains including vectors with different copy numbers. BW25113(DE3) cells containing the pET24ma::gmas was selected for strains. The optimal temperature, pH, and metal ion concentration were 50℃, 7, and 5 mM MnCl₂, respectively. Additionally, ATP was found to be an important factor for producing high concentration of ʟ-theanine so several strains were tested during the reaction for ATP regeneration. Baker's yeast was found to decrease the demand for ATP most effectively. Addition of potassium phosphate source was demonstrated by producing 4-fold higher ʟ-theanine. To enhance the conversion yield, GMAS was additionally overexpressed in the system. A maximum of 198 mM ʟ-theanine was produced with 16.5 mmol/l/h productivity. The whole-cell reaction involving GMAS has greatest potential for scale-up production of ʟ-theanine.

• Molecular & Cellular Toxicology
• /
• v.3 no.2
• /
• pp.90-97
• /
• 2007

8-Hydroxyquinoline is used as antibacterial agent and antioxidant based on its function inducing the chelation of ferrous ion present in host resulting in production of chelated complex. This complex being transported to cell membrane of bacteria and fungi exerts antibacterial and antifungal action. In this study, we have carried out in vitro genetic toxicity tests and microarray analysis to understand the underlying mechanisms and the mode of action of toxicity of 8-hydroxyquinoline. TA1535 and TA98 cells were treated with 8-hydroxyquinoline to test its toxicity by basic genetic toxicity test, Ames and two new in vitro micronucleus and COMET assays were applied using CHO cells and L5178Y cells, respectively. In addition, microarray analysis of differentially expressed genes in L5178Y cells in response to 8-hydroxyquinoline were analyzed using Affymatrix genechip. The result of Ames test was that 8-hydroxyquinoline treatment increased the mutations in base substitution strain TA1535 and likewise, 8-hydroxyquinoline also increased mutations in frame shift TA98. 8-Hydroxyquinoline increased micronuclei in CHO cells and DNA damage in L5178Y. 8-Hdroxyquinoline resulted in positive response in all three tests showing its ability to induce not only mutation but also DNA damage. 783 Genes were initially selected as differentially expressed genes in response to 8-hydroxyquinoline by microarray analysis and 34 genes among them were over 4 times of log fold changed. These 34 genes could be candidate biomarkers of genetic toxic action of 8-hydroxyquinoline related to induction of mutation and/or induction of micronuclei and DNA damage. Further confirmation of these candidate markers related to their biological function will be useful to understand the detailed mode of action of 8-hydroxyquinoline.