• Journal of Life Science
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• v.18 no.4
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• pp.482-487
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• 2008

In this study, we screened and identified the bacterial strain showing high alkaline pretense inhibitor activity from marine environment. Nine bacterial strains with alkaline pretense inhibitor activity were isolated from marine sediments. Among them, strain C12 had the highest alkaline pretense inhibitor activity and was selected for further taxonomical study. On the basis of morphological and physiological characteristics, strain C12 was identified as the genus Streptomyces. A phylogenetic analysis of the 165 rDNA showed that the isolated strain was actually a member of the genus Streptomyces, because the determined sequence exhibited a higher homology with Streptomyces thermocarboxydus. Morphological characteristics showed cylindrical spore chain and smooth spore surface by scanning electron microscope. Strain C12 was grown on all media except for ISP 9 agar. This strain could be grown in the medium containing up to 9% NaCl.

• Journal of Life Science
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• v.23 no.2
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• pp.190-196
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• 2013

The sea squirt, Halocynthia roretzi, has experienced mass mortality due to softness syndrome. The identification of disease-induced genes can provide insights into the development of this syndrome. To identify the genes, we performed differentially expressed gene (DEG) analysis. The expression of the phosphoglycerate kinase (HrPGK) gene was significantly decreased in diseased sea squirts compared to normal ones. We confirmed the result of the DEG analysis through RT-PCR and real-time PCR. In addition, we detected single nucleotide polymorphisms at position -106 (A/T) and -254 (G/T) in the HrPGK gene promoter by genotyping analysis. At the -106 site of the HrPGK gene, the frequency of the AA allele in disease-resistant sea squirts was about two-fold higher than that of sensitive ones, and the frequency of the TT allele in the disease-resistant sea squirts was about six-fold lower. At the -254 site of the HrPGK gene, the frequency of the GT and the GG allele was approximately two-fold higher and two-fold lower, respectively, in the disease-resistant sea squirts compared to the disease-sensitive ones. Analysis of the relationship between the genotypic variation at the -106/-254 promoter and the expression of HrPGK mRNA showed that HrPGK mRNA expression was higher in the -106/-254 AA/GT genotype samples than in the -106/254 TT/GG genotype ones. These results show that sea squirts harboring the AA/GT genotype may have more resistance to mortality than the sea squirts with other genotypes.

• Molecules and Cells
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• v.40 no.2
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• pp.123-132
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• 2017

Insulin signaling is coordinated by insulin receptor substrates (IRSs). Many insulin responses, especially for blood glucose metabolism, are mediated primarily through Irs-1 and Irs-2. Irs-1 knockout mice show growth retardation and insulin signaling defects, which can be compensated by other IRSs in vivo; however, the underlying mechanism is not clear. Here, we presented an Irs-1 truncated mutated mouse ($Irs-1^{-/-}$) with growth retardation and subcutaneous adipocyte atrophy. $Irs-1^{-/-}$ mice exhibited mild insulin resistance, as demonstrated by the insulin tolerance test. Phosphatidylinositol 3-kinase (PI3K) activity and phosphorylated Protein Kinase B (PKB/AKT) expression were elevated in liver, skeletal muscle, and subcutaneous adipocytes in Irs-1 deficiency. In addition, the expression of IRS-2 and its phosphorylated version were clearly elevated in liver and skeletal muscle. With miRNA microarray analysis, we found miR-33 was down-regulated in bone marrow stromal cells (BMSCs) of $Irs-1^{-/-}$ mice, while its target gene Irs-2 was up-regulated in vitro studies. In addition, miR-33 was down-regulated in the presence of Irs-1 and which was up-regulated in fasting status. What's more, miR-33 restored its expression in re-feeding status. Meanwhile, miR-33 levels decreased and Irs-2 levels increased in liver, skeletal muscle, and subcutaneous adipocytes of $Irs-1^{-/-}$ mice. In primary cultured liver cells transfected with an miR-33 inhibitor, the expression of IRS-2, PI3K, and phosphorylated-AKT (p-AKT) increased while the opposite results were observed in the presence of an miR-33 mimic. Therefore, decreased miR-33 levels can up-regulate IRS-2 expression, which appears to compensate for the defects of the insulin signaling pathway in Irs-1 deficient mice.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.719-730
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• 2014

This study was conducted to select proper soil amendments in order to reduce the occurrence of potato scab and maintaining soil health by applications of dolomitic lime, sulfur, potassium sulfate, shell meal fertilizer, silicate fertilizer, lime nitrogen and ammonium sulfate fertilizer in different pH levels of volcanic ash soil with continuous cultivation of potato. In potassium sulfate-applied plot with a low soil pH, the incidence rate and disease severity of scab were lowest at 84.4% and 28.4%, respectively. Those were lowest among the treatments. Value of potato scab control was 12.3% and marketable yield of potato was highest at 93.2%. In lime nitrogen-applied plot (60 kg/10a), the incidence rate was low at 38.3%, and control value was 23.8% and marketable yield of potato was high at 66.3%. In relatively higher pH soils, the incidence rate of scab was lowest at 38.3% in the lime nitrogen-applied plot (60 kg/10a). Value of potato scab control was 23.8%, which was four times higher than that in sulfur-applied plot. Marketable yield of potato was highest at 66.3% in the lime nitrogen-applied plot. In the lime nitrogen plot infected with potato scab pathogen such as S. acidiscabies and S. scabiei were remarkably lower than other soil amendments at 2.5, 5, and 10 g/L concentrations of lime nitrogen using Glucose Yeast Malt (GYM) medium. In conclusion, this study suggests that potassium sulfate application in low pH soil (less than pH 5) and lime nitrogen application in relatively higher pH soil (more than pH 6) before potato seeding might be helpful to reduce the occurrence of potato scab.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.387-393
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• 2010

The free sugar content and related enzymes of four different parts, inner, outer, stylar end and stem end, of 'Changhowon Hwangdo' peach ($Prunus$ $persica$, L. Batsch) fruit were compared from August to September in 2006, i.e., from 120 to 150 days after full bloom (DAFB). The soluble solids content (SSC) of stylar end was the highest among the four fruit parts at 150 DAFB. Changes of free sugar content were similar to that of SSC in the four parts. The starch content at the stylar end was the highest at 120 DAFB, while all the other parts showed low starch contents at 150 DAFB. The free sugar composition of peach changed during fruit development. The sucrose was low at 120 DAFB and increased gradually in all parts of peach fruit. On the contrary glucose, fructose and sorbitol decreased with fruit development. The free sugar contents and related enzymes activities were investigated during fruit development. The rapid increase of sucrose contents during fruit development was more affected by sucrose synthase than sucrose phosphate synthase. Activity of SS in the four fruit parts increased continuously over the fruit development period, but activity of acid invertase showed a downward trend. This study found that the free sugar content was affected by enzyme activity for the synthesis or the cleavage. However, it was very difficult to explain sugar accumulation of peach segments with related-enzymes.

• Korean Journal of Food Science and Technology
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• v.6 no.4
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• pp.241-248
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• 1974

Amylase 를 사용(使用)하여 전분자원(澱粉資源)으로부터 maltodextrin 및 포도당(葡萄糖) 액당(液糖)에 이르기까지 단계적(段階的)으로 감미도(甘味度)와 기능적(機能的) 특성(特性)이 다른 감미료(甘味料)를 생산(生産)할 수 있으며, 다방면(多方面)으로 식품공정(食品工程)에 이용(利用)되고 있다. 근래(近來)에 와서 개발(開發)된 glucose isomerase 의 산업적(産業的) 이용(利用)은 감미료(甘味料)가 설탕에 비(比)해 떨어지는 포도당(葡萄糖)을 이성화(異性化)시켜 과당(果糖)을 생성(生成)함으로써 감미료(甘味料)를 설탕과 대등(對等)하게 높일 수 있게 되어 앞으로 설탕 대치감미료(代置甘味料)로 쓰일 수 있는 경제적(經濟的)인 감미자원(甘味資源)임을 강조(强調)하고져 한다. 따라서 전분자원(澱粉資源)으로부터 얻을 수 있는 탄수화물(炭水化物) 감미료(甘味料)는 비단 기능적(機能的) 특성(特性)뿐만 아니라 감미료(甘味料)도 각층(各層) 감미제품(甘味製品)이며, 이러한 감미료(甘味料)는 감미원(甘味源)으로만 볼 것이 아니라 적절(適切)한 기능적(機能的) 특성(特性)을 찾아서 식품공정(食品工程) 이용(利用)하는 것이 중요(重要)하다. 감미료(甘味料) 이용(利用)의 과학화(科學化)는 식료제품(食料製品)의 경제적(經濟的) 수익(收益)을 얻을 뿐 아니라 제품(製品)의 품질향상(品質向上)에도 기여(寄與)하는바 크리라 생각(生覺)한다. 우리나라에 있어서의 전분당(澱粉糖) 산업(産業)은 아직 그 규모(規模)가 작으며, 물엿 및 포도당(葡萄糖) 생산량(生産量)은 각각(各各) 연간(年間) 약(約) 30,000둔(屯)과 15,000둔미만(屯未滿)이며 그 생산공정(生産工程)도 개량(改良)해 나갈 바 적지 않다. 원당(原糖) 수급(需給)의 난황(難況)과 더부러 염가(廉價)의 전분당(澱粉糖) 및 이성화당(異性化糖)의 개발생산(開發生産)이 시급(時急)하며 이런 감미원(甘味源) 생산공장(生産工場)의 대규모화(大規模化)로 경제적(經濟的) 양산(量産)을 서둘러야 될 줄 생각(生覺)한다. 우선적(優先的)으로 소요(所要)의 효소생산(酵素生産)에 대(對)한 개발연구(開發硏究)가 앞서야 하며, 이어서 전분(澱粉)으로부터 이성화당(異性化糖)에 이르기까지 단계적(段階的) 효소처리공정(酵素處理工程)의 확립(確立)과 새로운 공정(工程)의 개발연구(開發硏究)가 이루어져야 하겠다. 나아가서 보다 더 경제적(經濟的) 감미료(甘味料)의 생산(生産)과 생산공정(生産工程)의 능율화(能率化)를 위(爲)하여 전분당화(澱粉糖化) 및 이성화(異性化) 공정(工程)의 연속화(連續化)가 필연적(必然的)이며, 이에 소요(所要) 및 불용성(不溶性) 효소(酵素)의 생산공정(生産工程)도 연구(硏究)되어야 한다.

• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.123-133
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• 1972

Over 90 of lysine producing auxotrophs were obtained from Corynebacterium sp. S-27-12, Brevibacterium flavum ATCC 15168 and Micrococcus glutamicus ATCC 13032 by UV light, $Co^{60}$ irradiation and N-methyl-N'-nitro-N-nitrosoguanidine treatment. One of the mutant, Brev. flavum U46-N59, was identified as a leucine auxotroph and accumulated lysine during flask (500 ml) cultivation (180 strokes/min.) up to 21.6 mg per ml of broth at pH 7.5 and $28^{\circ}C$ after 4 days. The medium consisted of glucose, 100; urea, 10; corn steep liquor, 40; $KH_2PO_4,\;2;\;K_2HPO_4,\;0.5;\; MgSO_4.\;7H_2O,\;0.4;\;antifoam\;S-57,\;1g;\;Fe_2(SO_4)_3.XH-2O,\;10;\; MnCl_2,\;4H_2O,\;10mg;\;biotin,\;30;\;thiamine-HCl,\;100{\mu}g$in 1l of distilled water, and 40 U/ml of penicillin was added after 36 hrs fermentation.

• Korean Journal of Food Science and Technology
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• v.7 no.3
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• pp.141-147
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• 1975

Survial and emergency food packets were developed for use by people isolated in adverse circumstances. These products are made from cereals suchasrice, barley and wheat, and from nutritionally defined products, such as glucose, sodium caseinate, powdered milk, hydrogenated vegetable fat and so on. The caloric distribution of the survial packet was adjusted to 55% carbohydrate, 33% fat, and 12% protein for maximum body water retention. The raw materials were mixed thoroughly and then compressed into bars at 4,000 psi (survial) and at 7,000 psi (emergency). Compressed bars of the emergency packets were coated with edible coatings for protection from insects and microorganisms and prevention of cracking. These products are 4.0-4.4 Cal. per gram and 4.2-4.9 Cal. per cubic centimeter. The texture of the bars makes them convenient to carry and eat.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.544-548
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• 2014

This study was conducted to investigate the nutritional components and quality characteristics of the root of Allium hookeri grown in Korea and Myanmar. The root of A. hookeri grown in Hadong, Korea (KR), contained higher levels of carbohydrate, crude ash, and crude lipid, but the root of A. hookeri grown in Shan, Myanmar (MR), contained higher levels of crude protein and crude fiber. The free sugar and organic acid contents were higher in KR than in MR. Fructose, glucose, and sucrose were the major free sugars and arginine was the major free amino acid. KR contained higher amounts of essential amino acids, non-essential amino acids, ${\gamma}$-amino butyric acid, and citrulline than MR. Potassium was a prominent mineral constituent in both KR and MR, and KR contained higher mineral content than MR. KR contained twice the amount of sulfur and crude saponin, relative to MR.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.369-374
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• 2014

The physiological characteristics of kiwi (Actinidia delicosa) fruit were analyzed, which inclued its nutritional composition, in vitro-antioxidant activities, and neuronal cell protective effects. The most abundant components of mineral, amino acid, and fatty acid were found to be potassium (K), glutamic acid, and a-linolenic acid, respectively. The major free sugars were fructose, glucose, and sucrose. In addition, ${\beta}$-carotene and vitamin C contents were $1.35{\mu}g/100mL$ and 29.21 mg/100 g, respectively. The 2,2'-azinobis-(3-ethylbenothiazline-6-sulfonic acid) (ABTS) radical-scavenging activity of the n-hexane fraction obtained from the kiwi extract was 10.52% at a concentration of $1000{\mu}g/mL$. The malondialdehyde (MDA) inhibition of the n-hexane fraction was found to increased in a dose-dependent manner. The intracellular reactive oxygen species (ROS) accumulation after hydrogen peroxide ($H_2O_2$) treatment of PC12 cells was significantly reduced in the presence of the n-hexane fraction compared to PC12 cells treated with $H_2O_2$ only. Moreover, in the a MTT assay, the n-hexane fraction showed in vitro-protective effects against $H_2O_2$-induced neurotoxicity.