• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.75-82
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• 2003

The cellular responses of RDX-degrading bacterium, Pseudomonas sp. HK-6 to explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were examined. Strain HK-6 grown at different RDX concentrations was found to demonstrate the survival rate in proportional to the rate of the stress shock proteins produced in this bacterium. Analysis of total cellular fatty acid acids showed that lipids 10:0 iso and 14:1 $\omega$5c/$\omega$5t increased approx three times in strain HK-6 grown on RDX media than TSA media. SDS-PAGE and Western blot using anti-DnaK and GroEL revealed that several stress shock proteins including 70 kDa DnaK and 60 kDa CroEL were newly synthesized in strain HK-6 exposed to different RDX concentrations in exponentially growing cultures. 2-D PAGE of soluble protein fractions from the culture of HK-6 exposed to RDX demonstrated that approximately 300 spots were observed on the silver stained gel ranging from pH 3 to pH 10. As a result, 10 spots were significantly induced and expressed in response to RDX. Scanning electron microscopy fur the cells treated with 0.135 mM RDX for 12 hrs showed the presence of perforations and irregular rod shapes with wrinkled surfaces.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.537-544
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• 2014

Kwamaegi is a traditional Korean seafood made from the flesh of Pacific saury Cololabis saira. It is recognized as a valuable, healthy food containing the ${\omega}$-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). This study was conducted in order to obtain basic data for application to the canning process of Kwamaegi using red pepper paste with vinegar. Commercial Kwamaegi was cut into $2{\times}3cm$ lengths and 90 g was put into cans (301-3). Then, 60 g of water was added and precooked for 10 minutes at $100^{\circ}C$. The water was drained after precooking. The precooked Kwamaegi was packed into cans, and 60 g of red pepper paste with vinegar was added. The cans were seamed using a vacuum seamer, then sterilized for differing times (8-12 minutes) in a steam system retort at $121^{\circ}C$. Parameters such as: pH, TVB-N, amino-N, total amino acid content, free amino acid content, color value (L, a, b), texture profile, TBA value, mineral content, sensory evaluation and viable bacterial count of the product produced under varying sterilization times (8-12 minutes) were measured. There were no remarkable differences between sterilization conditions and textural characteristics. The results showed that product sterilized for 8 minutes proved to be the most desirable.

• Journal of Life Science
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• v.19 no.12
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• pp.1737-1742
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• 2009

It has been known that Linum usitatissimum and Perilla frutescens are dietary sources of possible chemopreventive compounds such as lignans and $\alpha$-linolenic acid. Here, we investigated and compared the inhibitory effects of methanol extracts from Linum usitatissimum and Perilla frutescens on mutagenicity using the Ames test, and growth of human cancer cells (AGS human gastric adenocarcinoma, HT-29 human colon cancer, Hep 3B hepatocellular carcinoma cells). In the Ames test system using Salmonella typhimurium TA100, aflatoxin $B_1$ ($AFB_1$)-induced mutagenicity was significantly inhibited by treatment with the methanol extract from either Linum usitatissimum or Perilla frutescens (p<0.05) in a dose dependent manner. As for N-methyl-N'-nitro-N-nitrosoguamidine (MNNG)-induced mutagenicity, the methanol extracts (5 mg/assay) from Linum usitatissimum and Perilla frutescens showed 63% and 78% inhibitory rates, respectively, indicating that Perilla frutescens possessed stronger antimutagenic activity than did Linum usitatissimum. Inhibitory effects of methanol extracts from Linum usitatissimum and Perilla frutescens on the growth of human cancer cells (AGS, HT-29 and Hep 3B) appeared to increase dose dependently, and the inhibition was more effective against AGS and HT-29 compared to Hep 3B cells. Our results suggested that the methanol extract from Perilla frutescens showed stronger antimutagenic activity than that from Linum usitatissimumas assayed by the Ames mutagenic test, whereas the methanol extract from Linum usitatissimum was more effective than its counterpart for growth inhibition of human cancer cells. It is concluded that intake of Linum usitatissimum and Perilla frutescens as sources of omega-3 fatty acids will be beneficial for preventing cancer.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.531-536
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• 2004

Synthesis conditions were optimized using response surface methodology for producing structured lipids (SL) by interesterification of DHA-enriched algae oil derived from microalgae, Schizochytrium sp. and corn oil. Reaction was performed fer 24 hr at $55^{\circ}C$ catalyzed by immobilized lipase from Rhizomucor miehei (RM IM) in shaking water bath. Major fatty acids of SL were palmitic (21.70 mol%), oleic (20.20 mol%), and linoleic (27.34 mol%) acids, and DHA (15.06 mol%). To separate newly synthesized SL-triglycerides (TG) species, HPLC with evaporative light scatting detector (ELSD) was used. Production conditions were optimized using central composite design with reaction temperature $(35-75^{\circ}C,\;X_1)$, reaction time $(2-42\;hr,\;X_2)$, and enzyme concentration $(2-14%,\;X_3)$ as variables. When variables were $70.28^{\circ}C\;(X_1),\;28.74\;hr\;(X_2),\;and\;11.30%\;(X_3)$, maximum content of selected three peaks of synthesized SL-TG species was predicted as 6.97 area%.

• Journal of the Korean Dietetic Association
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• v.4 no.2
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• pp.160-167
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• 1998

Current status of nutrient fortification in processed food in Korea were presented by analyzing the information shown on food labels. The obtained information was assessed by the regulations on food fortification in both Korea and other countries including Codex. The most current regulations were gathered from internet. The results are summarized as follows. 1. Major nutrients fortified were calcium, Vit C, Vit B complex, iron and fiber. The forfified foods were not limitted to certain food group with more frequent fortification in snackfoods, cereal, ramyun, retort pouch foods, milk, and youguart. The descriptive terms of nutrition label for the fortification were various including high, supplemented, added, source, fortified, and abundance though the difference among these terms were not distinct. 2. Current regulation on nutrition label requires to give the content of the fortified nutrient and % RDA. However not all of food items carry above information. Also some ingredients such as chitosan, DHA, taurine, $\omega$-3 fatty acid, chondrichin, bifidus were supplemented mainly to the snack foods which FDA(USA) does not allow to be fortified. 3. The nutrient most frequently fortified was calcium and general practice of fortification appears to follow the regulation in Korea. Presently the regulation itself is not well described, this nutient fortification can cause toxic effect. Since calcium was supplemented to wide range of food group consumers who are not conscious of the safe upper limit may intake the fortified food up to the level of 2g/day. 4. For the effective fortification in Korea, the regulation on fortification should be reformed in accordance with the international guideline Codex and the regulations in other countries especially in America and Japan.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.288-294
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• 1993

Solubilities of urea-crystallized tuna oil methyl esters in supercritical carbon dioxide were determined by a flow through extraction reactor. Experimental results obtained under a quasi-equlibrium condition showed that at 150 bar, solubilities of the esters in supercritical $CO_2$ were 0.075, 0.028 and 0.006(w/w) at $40^{\circ}C,\;60^{\circ}C\;and\;80^{\circ}C$, respectively. In the pressure and temperature ranges $(100{\sim}200bar\;and\;40{\sim}80^{\circ}C)$, the solubility increased with the density of $CO_2$. However, selectivity of supercritical carbon dioxide on the extracted compounds was much better at low density than at high density. Supercritical fractionation with a temperature gradient $(50{\sim}75^{\circ}C)$ resulted in concentrates of EPA and DHA in purities of 12% and 85%, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.182-186
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• 2013

In this study, we examined the chemical properties and microbial community characteristics in 25 controlled horticultural soils (CHS) sampled from Gyeongnam Province by fatty acid methyl ester (FAME) method. The electrical conductivity of watermelon CHS was significantly (p < 0.05) higher than those of red pepper CHS, pumpkin CHS, and strawberry CHS. The amounts of total FAMEs, total bacteria, gram-negative bacteria, gram-positive bacteria, and fungi were significantly (p < 0.05) higher in red pepper CHS than those in strawberry CHS and pumpkin CHS. In addition, higher (p < 0.05) ratios of cy19:0 to $18:1{\omega}7c$ were detected in tomato CHS than those in watermelon CHS, pumpkin CHS, and red pepper CHS. This implied that microbial communities of tomato CHS were stressed more than other species of cultivation soils. Actinomycetes community in red pepper CHS was significantly (p < 0.05) higher than those in tomato CHS, strawberry CHS, and watermelon CHS. Differences in soil microbial community composition were highly associated with cultivated crop species which might result from the management inputs such as fertilizer, herbicide, and irrigation.

• Journal of Life Science
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• v.27 no.10
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• pp.1152-1160
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• 2017

A unicellular green alga was axenically isolated from a tidal pool on Ulleung-do, Korea. Morphological, molecular, and biochemical analyses revealed that the isolate belonged to Auxenochlorella protothecoides. The current study is the first record of this species in Korea. The microalgal strain was named as A. protothecoides MM0011 and its growth, lipid and pigment compositions, and biomass properties were investigated. The strain is able to thrive in a wide range of temperatures ($5{\sim}35^{\circ}C$) and to withstand up to 1.5 M NaCl. The results of GC/MS analysis showed that the isolate was rich in nutritionally important polyunsaturated fatty acids (PUFAs). Its major fatty acids were linoleic acid (27.6%) and ${\alpha}-linolenic$ acid (39.6%). Thus, this indigenous microalga has potential as an alternative source of ${\omega}3$ and ${\omega}6$ PUFAs, which currently come from fish and plant oils. Also, the HPLC analysis revealed that the value-added antioxidant, lutein, was biosynthesized as the accessory pigments by the microalga. A proximate analysis showed that the volatile matter content was 85.6% and an ultimate analysis indicated that the gross calorific value was $20.3MJ\;kg^{-1}$. Since 40.5% of total nitrogen and 27.9% of total phosphorus were removed from the medium, respectively, it also has potential as a feedstock for biofuel applications which could be coupled to wastewater treatment. In addition, the biomass may also serve as an excellent animal feed because of its high protein content (51.4%). Therefore, A. protothecoides MM0011 shows promise for application in production of microalgae-based biochemicals and as a biomass feedstock.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.418-427
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• 2003

Conjugated linoleic acid (CLA) is the mixture of positional and geometric isomers of linoleic acid (LA, C18:2 $\omega$6), which is found abundantly in dairy products and meats. This study was peformed to investigate the anticarcinogenic effect of CLA in MCF-7 breast cancer cells. MCF-7 cell were treated with LA and CLA at the various concentrations of 15, 30, 60, 120 UM each. After incubation for 48 and 72 hours, cell proliferation, fatty acids incorporation into cell, peroxidation and activities of antioxidant enzymes were measured. Postaglandin E$_2$ (PGE$_2$) and thromboxane $A_2$ (TXA$_2$) were measured for the eicosanoids metabolism. There was no cell growth differences in both of LA and CLA treated MCF-7 cells at 48 hr incubation. Compared to LA, cell growth was decreased by CLA treatment according to increasing concentration at longer incubation times, respectively (p<0.05). Both of LA and CLA was incorporated into the cellular lipids 22~54% higher than in control but LA incorporation was not so linear as CLA according to concentration. Arachidonic acid (C20:4, $\omega$6) was synthesized after treatment of LA but did not in CLA, respectively. The lipid peroxide concentration in LA 120 $\mu$M group increased as 1.7 times as that in CLA 120 $\mu$M treated. The activities of antioxidant enzymes such as glutathione peroxidase and glutathione reductase were increased by the supplementation with CLA 120 $\mu$M at 72 hr incubation (p<0.001) compared to LA, otherwise activity of superoxide dismutase was not different in both. PGE$_2$ and TXA$_2$ levels were lower in condition of CLA treatments according to lower levels of arachidonic acids than those in LA treated group, respectively. Overall, the dietary CLA might change the MCF-7 cell growth by the changes of cell composition, production of lipid peroxide, activities of antioxidant enzymes and eicosanoid synthesis compared to dietary LA.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.61-70
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• 2020

A eukaryotic microalga was isolated from seawater in Janghang Harbor, Korea and its morphological, molecular, and physiological characteristics were investigated. Due to its simple morphology, no distinctive characters were found by morphological observation, such as light microscope or scanning/transmission electron microscopy (S/TEM). However, molecular phylogenetic evidence inferred from the concatenated small subunit (SSU) 18S rRNA and internal transcribed spacer (ITS) sequence data indicated that the isolate belonged to the newly described Micractinium singularis. Furthermore, it was clustered with Antarctic Micractinium strains and it also showed a psychrotolerant property, surviving at temperatures as low as 5℃. However, its optimal growth temperatures range from 15℃ to 25℃, indicating that this microalga is a mesophile. Additionally, gas chromatography-mass spectrometry (GC/MS) analysis showed that the isolate was rich in nutritionally important omega-3 polyunsaturated fatty acid, and high-performance liquid chromatography analysis (HPLC) revealed that the high-value antioxidant lutein was biosynthesized as an accessory pigment by this microalga, with glucose as the major monosaccharide. Therefore, in this study, a Korean marine M. singularis species was discovered, characterized, and described. It was subsequently added to the national culture collections.