• ALGAE
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• v.31 no.3
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• pp.257-266
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• 2016

Nitrogen is one of the most critical nutrients affecting cell growth and biochemical composition of microalgae, ultimately determining the lipid or carbohydrate productivity for biofuels. In order to investigate the effect of nitrogen sources on the cell growth and biochemical composition of the marine microalga Tetraselmis sp., nine different N sources, including NaNO₃, KNO₃, NH₄NO₃, NH₄HCO₃, NH₄Cl, CH₃COONH₄, urea, glycine, and yeast extract were compared at the given concentration of 8.82 mM. Higher biomass concentration was achieved under organic nitrogen sources, such as yeast extract (2.23 g L⁻¹) and glycine (1.62 g L⁻¹), compared to nitrate- (1.45 g L⁻¹) or ammonium-N (0.98 g L⁻¹). All ammonium sources showed an inhibition of cell growth, but accumulated higher lipids, showing a maximum content of 28.3% in ammonium bicarbonate. When Tetraselmis sp. was cultivated using yeast extract, the highest lipid productivity of 36.0 mg L⁻¹ d⁻¹ was achieved, followed by glycine 21.5 mg L⁻¹ d⁻¹ and nitrate 19.9 mg L⁻¹ d⁻¹. Ammonium bicarbonate resulted in the lowest lipid productivity of 14.4 mg L⁻¹ d⁻¹. The major fatty acids in Tetraselmis sp. were palmitic, oleic, linoleic and linolenic acids, regardless of the nutritional compositions, indicating the suitability of this species for biodiesel production.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.749-754
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• 2005

An antioxidant- producing bacterium was isolated from sea water in Jeju island. The isolated strain, SC2-1 was gram-positive, catalase positive, facultatively anaerobic, oxidase negative, motile and small rods. The strain utilized sucrose, dextrose, fructose, mannitol and maltose as a sole carbon and energy source and sodium chloride was required for the bacteria growth. The radical scavenging activity of the culture supernatants was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) method. This bacterium was identified based on cellular fatty acids analysis and 16S rDNA sequencing, and then named Exiguobacterium sp. SC2-1. The modified optimal medium compositions required the addition of maltose $2.5\%(w/v)$, yeast extract $1.5\%(w/v)$ and $KH_{2} PO_{4} 0.05\%(w/v)$ in marine broth (Difco. Co. USA). Antioxidant activity of under optimal culture conditions were $93\%$.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.169-172
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• 2000

Studies on extraction of red pigment was performed to provide the basic information for the utilization of red pigment as s new source of natural food colorant. A bacterium isolated from marine resources were carried out the test for excretion of red pigment. One strain of a marine bacterium, KSR-97 showed a high production of red pigment on the medium of colloidal chitin, peptone-yeast extract with minerals. In physicochemical and sensory properties in aqueous solution of red pigment was investigated at various condition of pH, temperature, concentration of ethanol and stability of storage. Potent antioxidative of red pigment was separated by thin layer chromatograpy, silica gel chromatography and reverse high performance liquid chromatography using ODS hypersil column.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.343-346
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• 2005

The isolated strain, SC2-1 was Gram-positive, catalase positive, facultatively anaerobic, oxidase negative, motile and small rods. The strain utilized sucrose, dextrose, fructose, mannitol and maltose as a sole carbon and energy source and sodium chloride required for the bacteria growth. The radical scavenging activity of the culture supernatants was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) method. This bacterium was identified based on cellular fatty acids analysis and 16S rDNA sequencing then named Exiguobacterium sp. SC2-1. The optimum culture conditions for production of antioxidant were $25^{\circ}C,$ pH 7.8 and NaCl concentration were 4%. The modified optimal medium compositions were maltose 2.5% (w/v), yeast extract 1.5% (w/v) and $KH_2PO_4$ 0.05% (w/v). Free radical scavenging activity of under optimal culture conditions were 93%.

• KSBB Journal
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• v.14 no.3
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• pp.351-357
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• 1999

A marine bacterium Bacillus cereus ASK202, agarase producing strain, was treated with some mutagenic agents, ultraviolte(UV), 1-methyl-3-nitro-1-nitrosoguanidine(NTG), and ethyl methane sulfonate(EMS), several times for the increasing of the agarase production After mutagen treatment, we isolated one mutant strain treated with NTG showed the highest stability and agarase productivity and named as Bacillus cereus ASK202-N3. This Bacillus cereus ASK202-N3 strain was well grown in the modified marine medium containing 0.5%(w/v) agar, 0.3%(w/v) yeast extract, and 5.0%(w/v) NaCl, and the optimal initial pH, temperature and culture time were 7.8, $25^{\circ}C$ and 32h, respectively. In the optimal culture conditions, the agarase production was increased to 5.3 fold(850units/L) compared to that of the wild type.

• Molecules and Cells
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• v.26 no.3
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• pp.291-298
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• 2008

Human karyopherin ${\beta}3$, highly homologous to a yeast protein secretion enhancer (PSE1), has often been reported to be associated with a mediator of a nucleocytoplasmic transport pathway. Previously, we showed that karyopherin ${\beta}3$ complemented the PSE1 and KAP123 double mutant. Our research suggested that karyopherin beta has an evolutionary function similar to that of yeast PSE1 and/or KAP 123. In this study, we performed yeast two-hybrid screening to find a protein which would interact with karyopherin ${\beta}3$ and identified apolipoprotein A-I (apo A-I), a secretion protein with a primary function in cholesterol transport. By using in vitro binding assay, co-immunoprecipitation, and colocalization studies, we defined an interaction between karyopherin ${\beta}3$ and apo A-I. In addition, overexpression of karyopherin ${\beta}3$ significantly increased apo A-I secretion. These results suggest that karyopherin ${\beta}3$ plays a crucial role in apo A-I secretion. These findings may be relevant to the study of a novel function of karyopherin ${\beta}3$ and coronary artery diseases associated with apo A-I.

• Journal of Food Hygiene and Safety
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• v.13 no.1
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• pp.6-13
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• 1998

This study was carried out to investigate the antioxidative activity on oxidaton of human low density lipoprotein from marine microorganisms. Bacillus sp. RH-5 producing antioxidative activity have been isolated and identified from coast sea in Pusan. Bacillus sp. RH-5 produced at highest level of antioxidative activity in the medium of 1.0% glucose, 0.25% polypepton, 0.25% yeast extract, 0.01% $FeSO_4{\cdot}7H_2O$ and 50% sea water. The optimal medium pH, cultural temperature and shaking time for the highest production as the antioxidant were 7.0, $30^{\circ}C$ and 48 hr, respectively. The culture broth inhibited the copper catalyzed oxidation of human low density lipoprotein (LDL) at the concentration of 500 and $1,000\;\mu\textrm{g}/ml$ ethylacetate extracts in the presence of $5\;\mu\textrm{M}\;CuSo_4$. The electrophoretic mobility of the LDL oxidized in the presense of $5\;\mu\textrm{M}\;CuSo_4$ was higher than that of native LDL.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.463-468
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• 2000

This study was conducted to investigate the effects of Kluyveromyces fragilis, Candida utilis and brewer's yeast as an additive in formulated diets containing different fish meal levels ($55{\%} and 45{\%}$) on growth and body composition of juvenile Korean rockfish (Sebastes schlegeli). Juvenile rockfish (average weight, 2.6 g) were distributed into 24 tanks with 3 replication groups and fed eight isoproteic ($41{\%}$) and isolipidic ($11{\%}$) diets containing each level ($3{\%}$) of K. frayilis, C. utilis and brewer's yeast as an additive. Survival rate of fish was not affected by dietary fish meal level and yeast kind (P > 0.05). Weight gain of fish fed the control and diets containing C. utilis and brewer's yeast was not influenced by fish meal level (P > 0.05), Weight gain of fish fed the $55{\%}$ fish meal diet containing C. utilis and $45{\%}$ fish meal diets containing K. fragilis and C. utilis was lower than that of fish fed the control diet (P < 0.05). Feed efficiency and protein efficiency ratio of fish fed the control and diet containing brewer's yeast were not affected by fish meal level, but these value of fish fed the diets containing K, fragilis and C. utilis were lower in $45{\%}$ fish meal diets than in $55{\%}$ fish meal diets. Hepatosomatic index and liver lipid content of fish fed the diet containing C. utilis were decreased regardless of fish meal level (P < 0.05), Hemoglobin, hematocrit, red blood cell, plasma total protein and plasma total glucose were not affected by dietary fish meal levels and yeast supplements (P > 0.05). From the above results, it can be concluded that yeast supplement in this formulated diet for growth of juvenile rockfish is not necessary.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1826-1831
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• 2006

A novel hyperthermophilic, anaerobic, heterotrophic archaeon, designated strain $NA1^T$, was isolated from a deep-sea hydrothermal vent area (depth, 1,650 m) within the Papua New Guinea-Australia-Canada-Manus (PACMANUS) field. Cells of this strain were motile by means of polar flagella, coccoid-shaped with a diameter of approximately $0.5-1.0{\mu}m$, and occurred as single cells. Optimal temperature, pH, and NaCl concentration for growth were $80^{\circ}C$, 8.5, and 3.5%, respectively. The new isolate was an obligate heterotroph that utilized yeast extract, beef extract, tryptone, peptone, casein, and starch as carbon and energy sources. Elemental sulfur was required for growth and was reduced to hydrogen sulfide. The G+C content of the genomic DNA was 52.0 mol%. Phylogenetic analysis of the 16S rRNA gene indicated that strain $NA1^T$ belongs to the genus Thermococcus, and the organism is most closely related to T. gorgonarius, T. peptonophilus, and T. celer; however, no significant homology was observed among species by DNA-DNA hybridization. Strain $NA1^T$ therefore represents a novel species for which the name Thermococcus onnurineus sp. novo is proposed. The type strain is $NA1^T$ (=KCTC 10859, =JCM 13517).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.319-328
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• 1997

To develop a beneficial microbial feed for the cultivation of rotifer, Brachionus plicatilis, an aerobic photosynthetic bacterium, Erythrobacter sp. $S\;\pi-I$ was isolated from marine structure at Haeundae beach in Pusan, Korea. Feeding effects of Erythrobacter sp. $S\;\pi-I$ on the growth of rotifer were analyzed comparing to other feeds such as PSB (purple nonsulfur bacteria), Chlorella sp. and baker's yeast. Erythrobacter sp. $S\;\pi-I$ contained more linoleic acid $(C_{18:3\omega3})$ and oleic acid $(C_{18:1\omega9})$ and amino acids than PSB (purple nonsulfur bacteria), Chlorella sp. and baker's yeast. The rotifer fed on Erythrobacter sp. $S\;\pi-I$ showed better effects than those fed on other feeds in the individual growth, size and weight. Also, the rotifer especially contained more eicosapentaenoic acid $(C_{20:5\omega3})$ and docosahexaenoic acid $(C_{22:6\omega3})$ in case of Erythrobacter sp. $S\;\pi-I$ feeding than the other feeds. In case of the feed of PSB and baker's yeast docosahexaenoic acid $(C_{22:6\omega3})$ did not show. In amino acid analysis, the rotifer fed on Erthrobacter sp, $S\;\pi-I$ showed more amino acid content comparing to those fed on other diets. Especially, arginine, isoleucine, histidine, lysine, methionine, phenylalanine, threonine, which are essential amino acid for fish growth, showed high contents. These results suggested that the aerobic photosynthetic bacterium, Erythrobacter sp. $S\;\pi-I$ would be a beneficial microbial teed for the cultivation of rotifer.