• Journal of Marine Bioscience and Biotechnology
• /
• v.6 no.2
• /
• pp.118-122
• /
• 2014

The ocean provide great benefits for microalgal mass cultures with maintaining stable temperature due to high specific heat, mixing by wave energy, and providing large area for large-scale microalgae cultures. In this study, we cultivated a marine green microalga, Tetraselmis sp. KCTC12432BP, using marine photobioreactors on the ocean for investigating the effect of $NaHCO_3$ concentration on the biomass productivities and evaluating the potential of ocean microalgae culture. The culture medium consist of three fold concentrated f/2-Si with 4 g/L of $NaHCO_3$, which is dissolved in natural seawater. After 11 days of cultivation, the cultures reached stationary phase at biomass concentration of 1.6 g/L. At that time, $NaHCO_3$ concentration of 0, 2, and 4 g/L were fed to the cultures. The daily productivities of 0.11, 0.19, 0.30 g/L/day were attained with feeding rate of 0, 2, and 4 g/L $NaHCO_3$, respectively. Biomass productivity of Tetraselmis sp. KCTC12432BP was a function of the $NaHCO_3$ feeding rate as expected. This research shows that the microalgae can grow with $NaHCO_3$ as carbon source in marine photobioreactors on the ocean while exploiting various benefits of ocean cultivation.

• Journal of Pharmacopuncture
• /
• v.23 no.3
• /
• pp.165-172
• /
• 2020

Objectives: In the past few years, herbal medicines have gained popularity over synthetic drugs because of their natural source and minimal side effects which has led to a tremendous growth of phytopharmaceuticals usage. With the development of nanotechnology, it provides alternative approaches to overcome several limitations using nano-formulations. In spite of considerable quantity of antianemic preparations with different iron forms available, currently additives are used and represented in modern pharmaceutical market. Iron deficiency anemia is a major global public health problem which particularly affects pregnant women, children and elderly persons. The situation is complicated because of disadvantages and drug side effects from existing antianemic medicines. There is a great demand for the development of new antianemic preparations. Green synthesis of iron oxide nanoparticles, possess high potential in this field. Methods: Our study focuses on developing green synthesis of iron oxide nanoparticles (IONPs) of 10-50 nm with spherical shape where different dosages were used -1 mg/kg, 10 mg/kg and 100 mg/kg for exposure in Wistar albino female rats for 28 days. The toxicity was assessed using various parameters such as measurements of the rat body and organ mass, hematology, biochemical evaluation and histopathological examinations. Results: No significant differences were observed in body and organ weights. Hematological indices also indicated no significant differences whereas biochemical factors showed increase in levels of direct bilirubin and globulin of medium as well as high dose and SGPT levels were increased only in high dose. The major organs (heart, kidney and liver) showed histopathological alterations in 10 and 100 mg/kg whereas brain showed only in 100 mg/kg. Conclusion: The toxicity of IONPs was found to be more significant when the concentration was increased; however, low doses can be used for further investigation as an antianemic preparation.

• Korean Journal of Microbiology
• /
• v.27 no.4
• /
• pp.404-414
• /
• 1989

Attempts were made to isolate and identify Gram-positive or lactic acid bacteria in Kimchi fermentation. Species diversity depended on isolation media and temperatures, and diversity tended to be reduced with decrease of temperature. MRS and KM (natural medium prepared from Kimchi materials) were suitable respectively for isolation and present number of species. Identification of isolates was performed by dichotomous identification schemes arranged on the basis of Bergey's manual of Systematic Bacteriology (1986). Gram-positive bacteria isolated at different temperatures (5, 15, $25^{\circ}C$) were 5 species of Leuconostoc, 4 species of Streptococcus, 3 species of Pediococcus, 2 species of Bacillus and 18 species of Lactobacillus. Species with high frequency of appearance were Lactobacillus plantarum, Streptococcus raffinolactis, Leuconostoc mesenteroides subsp. mesenteroides at $25^{\circ}C$, L. plantarum, Lactobacillus fructosus, L. mesenteroides subsp. mesenteroides at $15^{\circ}C$ and L. mesenteroides subsp. mesenteroides, Leuconosotoc paramesenteroides, Lactobacillus maltaromicus at $15^{\circ}C$. In general, Kimchi fermentation was achieved by Lactobacillus spp. (59.7% frequency) at $25^{\circ}C$ and Leuconostoc spp. (65.2% frequency) at $5^{\circ}C$. Pediococcus cerevisiae and Streptococcus faecalis which have been so far known as bacteria of Kimchi fermentation were not isolated.

• Korean Journal of Microbiology
• /
• v.33 no.2
• /
• pp.125-130
• /
• 1997

Microbial reduction of hexava1ent(VI) to trivalent(lII) chromium is regarded as one of the mechanisms that confers resistance to bacteria. In order to verify this hypothesis, we compared Cr(VI) resistance with Cr(VI) reduction among 20 phenotypically distinct environmental isolates from Cr-contaminated and uncontaminated soils. With glucose as an electron donor, Cr(VI) reduction by washed cell suspensions ranged from 0.014 to 0.305 mM Cr(VI) reduced $h^1$. Cr(VI) resistance of the isolates were measured by growth inhibitions on a liquid medium containing 2 mM Cr(VI) based on their decrease of $A_{630}1$ as compared to the controls without Cr(VI). The isolates had a broad range of resistance from no inhibition to 93.4% inhibition of their growth. Upon correlation analysis, there was no significant relationship between those two phenomena. At a population level, a comparison of % resistant viable counts among the Cr-contaminated and uncontaminated soils showed 19.1 % and 0.4% of their total viable counts, respectively. The difference of % resistance between two site,. strongly suggested that the Cr(VI) present in the soils influences natural selection for resistant phenotypes. However, it is unlikely that the Cr(VI) resistance is dependent solely on the reduction as judged by the correlation analysis.

• Journal of Environmental Science International
• /
• v.1 no.1
• /
• pp.77-88
• /
• 1992

Distribution patterns of the chemical species, contained or dissolved in the sediments and porewater, were studied from the submarine environments around Deok-Jeok Island, Yellow Sea. The sediments in the study area are predominantly composed of medium to coarse sands, and consequently of very low organic carbon (0.003%) -0.26%o dry weight sediments). As opposed to the strong enrichment of porewater with nutrients and heavy metals in the ordinarily muddy, organic-rich sediillents, the porewater enrichment is not intense in this sandy, organic-poor sediments: porewater phosphate is enriched to the maximum of only seven (average two) times over that in the bottom water. Concentrations of the heavy metals dissolved in porewater show a bit greater enrichment than the nutrient: Zn shows the lowest enrichment (7 times that of the bottom water) and Mn the highest (450 times that of the bottom water). However, these enrichments of the chemical species in porewater are the natural consequences of decomposition of the organic matter in sediments, and still fall short in the magnitude of those in the muddy, organic-rich sediments. Mining of the sands in the study area may pose a threat to the seawater quality as it causes a large scale porewater discharge to the bottom water. The additional supply of the nutrients by this discharge may develop an eutrophic state and, in consequence, an excessive nitrification of the water column. Since the residence times of the nutrients are much longer than those of the heavy metals, a long-term monitoring of the concentration changes in the porewater nutrients is very important to assess the potential deterioration of the seawater associated with the sand mining in the study area.

• The Journal of Engineering Geology
• /
• v.12 no.2
• /
• pp.151-166
• /
• 2002

Groundwater development as a means of acquiring subsidiary water resource is very important for the persistent security of water resource. Nowadays, pneumatic fracturing technology which was developed in the advanced countries is applied for increasing pumping rate and eliminating contaminants. This study gives an experimental data to clarify permeability characteristics of the single discontinuity which is newly developed or increased in aperture by the pneumatic fracturing or damage propagation of the natural barrier for the nuclear waste disposal. On the basis of understanding the relationship between permeability and hydraulic aperture the result could apply as one of the basic data for researches concerned with increasing pumping rate and eliminating contaminants. Hydraulic aperture is decreased exponentially with increasing confining pressure and proportioned to permeability in the same confining pressure. Especially, with the increasing aperture permeability of coarse- and medium- grained granite shows the more rapid increasing than that of fine- grained granite.

• Journal of Environmental Impact Assessment
• /
• v.19 no.2
• /
• pp.127-140
• /
• 2010

This study investigates the relation between the location of a habitat and the ecological connections according to the habitat type in the riparian zone at the Nonsan Stream and Yanghwa Stream. Stream habitat is classified into nine types for the aquatic insects and fish. For vegetation and birds, habitat is classified into two types of medium-scale streams, including both physical and chemical streams are analyzed accordingly. Nowadays, The fundamental goal of the river environment restoration enterprise is the rehabilitation or the restoration of the characteristic the river scenic or environment. For instance, The Channel habitats which has physical nature environment such as flat, speedy rapids, or closed-channel wetland, pool are constructed by artificial, Consequently, make them autogenesis smoothy eco-environment. However, the river environment are controlled not only physical environment, but it also need reasonable the quality of the water to compose smoothly. Finally, understanding what influence are effecting on physical habitat environment which are made by natural factors to water quality are very important factor for the river environment restoration enterprise Therefore, In this research, we are targeting to a basin to investigate the environment of the physical channel habitat and evaluate the changing of the water quality. This results will be a important characteristic that can judge the physical habitat and reciprocality connected to the water quality or adequacy of restoration technology. Therefore in this study, as a step to quantify functions and values of habitats and definite factors to perform habitat, we selected a representative stream of sand-stream, gravel-stream to classify habitat characteristics and quantified the physical, chemical, biological characteristics.

• Textile Coloration and Finishing
• /
• v.6 no.1
• /
• pp.33-43
• /
• 1994

In the present work, to clarify the mechanism of the neutral salt effect on the alkaline hydrolysis of PET, many salts with different cations like LiCl, NaCl, KCl, CsCl were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous solutions of many salts in alkali metal hydroxides under various conditions. Some conclusions obtained from the experimental results were summarized as follows. The reaction rate of the alkaline hydrolysis of PET was increased by the addition of neutral salts and In k was increased nearly linearly with the square root of ionic strength of reaction medium. This fact suggested that the ionic strength effect by Debye-Huckel and Bronsted theory was exerted on the reaction. The specific salt effect was also observed. The reaction rate was increased with the increase in the electrophilicity of cations of neutral salts, i. e., in the order of $Cs^+$/ < $K^+$/ $a^+$/ $i^$^+$. It was considered that the reaction rate was increased in the order of C $s^+$. < $K^+$. $a^+$. $i^+$. because the lowering effect of the cations on the negative charge of PET surface was increased with the electrophilicity of cations. It was thought that $E_{a}$ was increased because the cations of neutral salts decreased the negative charge of PET surface. It, however, was inferred from the increase in ${\Delta}$S＊ and the decrease in the ${\Delta}$G＊ that the cations of neutral salts associated with PET increased the collision frequency between carbonyl carbon and OH- ion and then accelerated the reaction rate.te.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.10
• /
• pp.1412-1422
• /
• 2012

The aim of this work was to establish the optimal conditions for production of carboxymethylcellulase (CMCase) by a newly isolated marine bacterium using response surface methodology (RSM). A microorganism producing CMCase, isolated from seawater, was identified as Cellulophaga lytica based 16S rDNA sequencing and the neighborjoining method. The optimal conditions of rice bran, ammonium chloride, and initial pH of the medium for cell growth were 100.0 g/l, 5.00 g/l, and 7.0, respectively, whereas those for production of CMCase were 79.9 g/l, 8.52 g/l, and 6.1. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ for cell growth were 6.25, 0.62, 0.28, and 0.42 g/l, respectively, whereas those for production of CMCase were 3.72, 0.54, 0.70, and 0.34 g/l. The optimal temperature for cell growth and the CMCase production by C. lytica LBH-14 were $35^{\circ}C$ and $25^{\circ}C$, respectively. The maximal production of CMCase under optimized condition for 3 days was 110.8 U/ml, which was 5.3 times higher than that before optimization. In this study, rice bran and ammonium chloride were developed as carbon and nitrogen sources for the production of CMCase by C. lytica LBH-14. The time for production of CMCase by a newly isolated marine bacterium with submerged fermentations reduced to 3 days, which resulted in enhanced productivity of CMCase and a decrease in its production cost.

• Microbiology and Biotechnology Letters
• /
• v.42 no.1
• /
• pp.89-92
• /
• 2014

The Wnt/${\beta}$-catenin pathway plays important roles in a variety of biological processes, such as cell proliferation, differentiation, and organ development. Here, we used a cell-based reporter assay to identify bryostatin-1, a natural macrocyclic lactone, as an inhibitor of the Wnt/${\beta}$-catenin pathway. Bryostatin-1 suppressed ${\beta}$-catenin response transcription (CRT), which was activated by a Wnt3a-conditioned medium (Wnt3a-CM), through a decrease in the intracellular ${\beta}$-catenin protein levels, without affecting its mRNA level. In addition, pharmacological inhibition of proteasome abrogated bryostatin-1-mediated down-regulation of the ${\beta}$-catenin protein level. Our findings suggest that bryostatin-1 attenuates the Wnt/${\beta}$-catenin pathway through the promotion of proteasomal degradation of ${\beta}$-catenin.