• Korean Journal of Ecology and Environment
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• 제40권3호
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• pp.431-438
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• 2007

This study was to test algal removal efficiency by top-down fish biomanipulation experiments in the laboratory during Agust${\sim}$September 2000. We selected eight candidate fishes for the biomanipulation. We set up the experiments of eight fish-treatment tanks (3${\sim}$6 fishes) with initial chlorophyll-${\alpha}$ concentrations (CHL-${\alpha}$) of $100{\sim}120{\mu}g\;L^{-1}$ and one control tank including no fish with the same initial CHL-${\alpha}$. All tanks were maintained water quality of dissolved oxygen $(5.3{\sim}8.2mg\;L^{-1})$ and pH $(7.4{\sim}8.1)$ in the tests. During the biomanipulation, DO and pH in the treatments were lower than those of the control, while conductivity increased gradually in the treatments. Biomanipulation experiments showed that CHL-${\alpha}$ increased 13% and 0% (mean values of 8 fishes) in the controls and treatments, respectively. These results indicate that algal growth was maintained in the control and fish treatments, but the rate of CHL-${\alpha}$ in the treatments was lower than that of the control. The removal rates of bluegreens algae decreased 32% in the control, and 20% in treatments (mean values of 8 fishes) respectively, In other words, bluegreen algae showed greater growth rate in the fish treatments than the control and this was due to higher nutrients supplied from fish excretions. Overall, simple fish biomanipulation on algal control was not effective at all in these laboratory tests.

• Korean Journal of Ecology and Environment
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• 제47권spc호
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• pp.10-18
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• 2014

The habitat characteristic of the Gammarus sobaegensis which is one of the Amphipoda kinds has been found inhabiting in the inter mountain stream at Ganseong stream. From the investigation, the main inhabitant area of the G. sobaegensis maintained the water temperature under $10^{\circ}C$ during the spring and autumn season, and the electric conductivity was also maintaining under $40{\mu}Scm^{-1}$. For the precipitation, for this year when the monthly accredited rainfall did not exceed 800 mm, it did not affect maintaining the population of the G. sobaegensis but when the monthly accredited rainfall exceeded 1,000 mm it was found to be working as a unfavorable condition for maintaining the population. The effect especially from this kind of rainfall created the flow of G. sobaegensis as well as the flow of the fallen leaves which are the food resources and affected the population of the G. sobaegensis as a multiple interruption reason. Among the Functional Feeding Groups (FFGs) distribution depending on the use of the food resources the shredders showed up in the ratio of 20% in the site 1~3, and showed a big difference with the site 4~7 as it showed up in the ratio near 10%. Also, after comparing the variation of the individual number among the G. sobaegensis and shredders at the site 1~3 where G. sobaegensis mainly shows up, it showed the same variation pattern except for 2009.

• Journal of Animal Environmental Science
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• 제16권3호
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• pp.215-226
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• 2010

The pig slurry leachate was dark brown-colored solution that leaches out of woodchip trickling filter. The purpose of this research was to investigate the effect of pig slurry leachate and byproduct on growth characteristics of leaf lettuce in hydroponics culture. The effects of addition of fish meal, bone meal and crab shell for the growth of leaf lettuce were investigated. Leaf lettuce were grown in each of six combination treatment solutions; slurry leachate, slurry leachate + fish meal, slurry leachate+bone meal, slurry leachate + crab shell and chemical hydroponic solution for lettuce based on EC content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of lettuce. The all of nutrient solution was adjusted 1.5 mS/cm in EC in hydroponics culture. 1. The pH level of leachate of trickling filter was increased and EC decreased gradually during treatment. Pig slurry leachate was low in suspended solids (SS), phosphorus (P), but rich in potassium (K). 2. The plot of slurry leachate (SL) was lowest in the growth characteristics of lettuce. The leaf length and width of lettuce treated with mixture plot of slurry leachate and fish meal (SL + FM) was higher compared with plot in slurry leachate. The chlorophyll reading was reduced in plot treated with slurry leachate, but that in plot of SL+FM was similar compared with control plot. 3. The fresh weight of lettuce showed lowest in the plot treated with slurry leachate. The addition of fish meal increased the yield of comparing plot of slurry leachate, but plots of bone meal and crab shell addition were not significantly difference. The fresh weight of leaf lettuce in plot of SL+FM was 87% as 400.0g compared with control. In conclusion, the mixture solution of pig slurry leachate and fish meal could be used as a nutrition solution of organic lettuce hydroponics.

• Journal of Animal Environmental Science
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• 제15권2호
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• pp.161-170
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• 2009

This experiment was conducted to investigate the effects of compost leachate and concentrated pig slurry on growth of pepper in substrate hyrdoponic culture. In process of composting, compost leachate was was through a saturated compost heap. Pig slurry was filtered by ultra filtration and concentrated by reverse osmosis process. The pig slurry was mixed with chemical nutrient solution and byproduct based on nitrogen content. Peppers were grown in the seven different hydroponic solutions; compost leachate (CL), concentrated pig slurry (CS), compost leachate + byproduct (CL+BP), concentrated pig slurry + byproduct (CS+BP), compost leachate 50% + nutrient solution 50% (CL+NS), concentrated pig slurry 50% + nutrient solution 50% (CS+NS) and chemical nutrient solution for pepper. The chemical nutrient solution was the standard solution of National Horticulture Research Station for the growth of pepper. The concentration of nutrient solution was adjusted $1.6{\sim}2.0mS/cm$ in EC. The compost leachate and concentrated pig slurry were low in phosphorus (P), calcium (Ca), magnesium (Mg), but rich in potassium (K). Growth characteristics as affected by the different nutrient solution were significantly different. Growth and fruit characteristics treated with CL 50+NS 50%CS and 50+NS 50% were similar with NS 100% control plot. The dry weight of stem and leaf were 107.4, 104.2g in plot of NS 100% and CS 50%+NS 50%, respectively. The fruit of pepper showed lowest in the plot treated with 100% concentrated pig slurry, and the growth of pepper severely decreased after application of 100% CS treatment. The yield of pepper was not significantly different between the plots treated with mixture of CS50 + NS50% and 100% nutrient solution treatment. Fruit yield of the compost leachate concentrated pig slurry plot were 59, 14% compared to control, repectively. In conclusion, the mixture solution of 50% of pig slurry and 50% of nutrient solution could be used as a nutrition solution of pepper in hydroponic culture.

• Journal of Life Science
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• 제15권6호
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• pp.1013-1021
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• 2005

The metagenomes of complex microbial communities are rich sources of novel biocatalysts. The gene encoding an extracellular $\alpha$-amylase from a genomic DNA of cow rumen was cloned in Escherichia coli DH5$\alpha$ and sequenced. The $\alpha$-amylase (amyA) gene was 1,893 bp in length, encoding a protein of 631 amino acid residues with calculated molecular weight of 70,734 Da. The molecular weight of the enzyme was estimated to be about 71,000 Da by active staining of a SDS-PACE. The enzyme was 21 to $59\%$ sequence identical with other amyloyltic enzymes. The AmyA was optimally active at pH 6.0 and $40\%$. The AmyA had a calculated pI of 5.87. AmyA expressed in E. coli DH5$\alpha$ was enhanced in the presence of $Mg^{2+}$ (20 mM) and $Ca^{2+}$ (30 mM) and inhibited in the presence of $Fe^{2+}$ and $Cu^{2+}$. The origin of amyA gene could not be confirmed by PCR using internal primer of amyA gene from extracted genomic DNA of 49 species rumen culturable bacteria so far. An amyh is supposed to obtained from unculturable rumen bacterium in cow rumen environment.

• Korean Journal of Food Science and Technology
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• 제23권3호
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• pp.256-261
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• 1991

To isolate new antioxidants from twelve edible seaweeds, mixed methanol and chloroform extract of marine algae was fractionated into several subfractions and their antioxidant activities were measured by using AOM and 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Especially the aqueous-methanol soluble fractions of brown and red algae showed a considerable antioxidant effect. Their antioxidant activities were stronger than synthetic antioxidants such as BHA, BHT, under the same concentration. Further fractionation of the aqueous-methanol soluble fractions using silica gel column chromatography yielded five subfractions. Among them methanol fraction exhibited high DPPH quenching activities. Also, it was confirmed to be benzene-derivative substances of two compounds by UV, HPLC, GC/MS analysis. Its each molecular weight was about 181, 238. These results suggested the existence of two effective natural antioxidant compounds in three edible marine algae.

• Journal of The Korean Society of Grassland and Forage Science
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• 제36권1호
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• pp.34-40
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• 2016

The objective of this study was to determine the effect of moisture content on the physical and chemical characteristics of Italian ryegrass cube. Cube quality according to moisture contents (15, 20, 25, and 30%) was determined. Cubes made with 15 to 20% moisture showed a little cracks. But, the amount of powder generate from these cubes were lower by 10 to 16% compared to other cubes made with 25 to 30% moisture contents. The highest hardness at 159 kg/f was obtained when the cube was made with 15% moisture content and the lowest was 70 kg/f when the cube was made with 30% moisture content. The electrical loading and surface temperature were increased when moisture content was decreased. The chemical compositions of cube were differ from those of raw materials. Crude protein (CP) and ether extract (EE) contents were increased after cubing works. However, crude fiber (CF), acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents were decreased after cubing. The crude ash content was not significantly (p > 0.05) different between raw material and cube. Higher moisture content resulted in higher crude protein content. However, crude fiber and crude ash content were not significantly (p > 0.05) different between each other. The contents of ADF and NDF were the lowest in cubes made with 30% moisture content. Our results suggest that the proper moisture content of Italian ryegrass cubing is recommended to be 15 to 20% and that cubing works should help increase forage quality.

• Korean Journal of Food Science and Technology
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• 제40권2호
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• pp.220-227
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• 2008

In this study, polysaccharides were isolated from Korean persimmon vinegar to characterize the polysaccharides existing as soluble forms within traditional Korean fermented beverages, and their immuno-stimulating activities were examined. Three successive chromatographies were used to purify the main polysaccharide in the persimmon vinegar, PV-1b-I, to homogeneity from the crude polysaccharide (PV-0). The molecular mass of PV-1b-I was estimated as 110 kDa and it contained significant proportions of mannose (46.8%), galactose (28.5%) and arabinose (19.1%). PV-1b-I strongly reacted with ${\beta}$-glucosyl Yariv reagent, suggesting the presence of an arabino-3,6-galactan moiety. PV-1b-I also induced high levels of macrophage activation and mitogenicity on murine splenocytes in vitro. The intravenous administration of PV-1b-I significantly augmented NK cytotoxicity against YAC-1 tumor cells. PV-1b-I also showed potent anticomplementary activity in a dose-dependent manner. Finally, C3 activation products were identified by crossed immunoelectrophoresis using anti-human C3 and the anti-complementary activity of PV-1b-I under $Ca^{2+}$-free conditions, suggesting that this PV-1b-I causes complementary activations via both alternative and classical pathways. From these results, one can conclude that Korean persimmon vinegar contains select polysaccharides in addition to healthy components, and these polysaccharides appear to provide immuno-stimulating activities beneficial to human health.

• Korean Journal of Food Science and Technology
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• 제49권4호
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• pp.369-376
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• 2017

Maturation of distilled spirit can generate diverse flavors and tastes. Rice Soju was matured in oak casks (MSO) and stainless steel containers (MSS) for one year at ambient temperature. Ipguk (Aspergillus luchuensis) and Saccharomyces cerevisiae Y88-4 were used, and reduced pressure ($110{\pm}20Torr$) distillation was applied to brew Soju. Acidity and conductivity were increased in both MSO and MSS. MSO reduced alcohol content (from 43 to 40%) and volume (from 18,000 to 12,730 mL), and significantly altered yellowness (from 0.2 to 30.2). Furthermore, MSO increased the isoamyl alcohol (from 276.7 to $339.2{\mu}g/mL$) and isobutyl alcohol (from 122.3 to $144.2{\mu}g/mL$) content. Gas chromatography-mass spectrometry was used to detect volatile compounds in Soju, which included 20 esters, 7 alcohols, 2 acids, and 5 miscellaneous compounds. Oak lactone was detected only in MSO and was considered as a specific flavor component associated with oak maturation. Thus, maturation materials contribute to the physicochemical property of distilled spirits.

• Korean Journal of Food Science and Technology
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• 제49권4호
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• pp.459-461
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• 2017

This study investigated the screening and optimization of nitrite production from fermented spinach extract using different lactic acid bacteria, fermentation temperature, and time. Spinach extract was fermented using various lactic acid bacteria at 24, 30, and $36^{\circ}C$ for 6, 12, 18, 24, 36, 48, 72, and 96 h in the presence of different carbohydrates (glucose, sucrose, fructose, and lactose). Lactobacillus farciminis (KCTC 3618) produced the highest amount of nitrite using fermented spinach extract at $30^{\circ}C$ for 28 h compared to Staphylococcus carnosus, L. coryniformis (KCTC 3167), L. fructosus (KCTC 3544), L. reuteri (KCTC 3677), L. amylophilus (KCTC 3160), L. hilgardii (KCTC 3500), L. delbrueckii (KCTC 1058), L. fermentum (KCTC 3112), L. plantarum (KCTC 3104), and L. brevis (KCTC 3498). Comparison of the yield at different fermentation temperatures showed that the highest amount of nitrite was produced using fermented spinach extract at $30^{\circ}C$. Similarly, maximum nitrite yield was observed after 36 h fermentationin in the presence of sucrose. Therefore, maximum nitrite production was observed upon L. farciminis-mediated fermentation of spinach extractat $30^{\circ}C$ for 36 h in the presence of sucrose.