• Journal of Life Science
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• v.11 no.6
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• pp.517-522
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• 2001

To Confirm the repression of off-odor and improvement of food quality in small black bean chungkugjang (SBC), some taste compounds of SBC added with kiwi and radish homogenate and fermented fro 3 days at 42$^{\circ}C$ were investigated. Contents of free amino acids in SBC were lower than that of soybean chungkugjang (SC) and were increased by adding kiwi and radish homogenate to black bean, indicating that two materials were effective to the enzymatic digestibility of soy protein. Of organic acids, citric acid was the most abundant, followed by acetic acid and lactic acid. Fatty acid composition was high in the order of linoleic acid (50.82~54.51%), oleic acid (17.76%~22.10%) and plamitic acid(12.13~13.79%). There were no significant difference in compositions of organic acids and fatty acids of chungkugjang. Major volatile compounds of SBC were indole , 2-5-dimethyl pyrazine and trimethyl pyrazine. Contents of alkyl pyrazines that contribute the characteristic aroma and flavor of SBC added and fermented with kiwi and radish homogenate were 3 times lower than those of SC. Uracil and UMP were major nucleic acie-drlated compounds in all four chungkugjangs. Contents of the other nucleic acid-related compounds were a similar trend in all chungkugjangs.

• Korean Journal of Microbiology
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• v.6 no.1
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.10-16
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• 1997

To confirm the possibility of seaweed extracts for functional food, water or ethyl alcohol solubles were extracted from laver, Porphyra yezoensis and evaluated those food components such as proteins, carbohydrates, nucleic acids, taurine, pigments and browning extent. The amount of proteins, polysaccharides and nucleic acids extracted decreased with increasing ethyl alcohol concentration, which was maximal when water was used as extraction solvent. The extractability of proteins, polysaccharides and nucleic acids was different between the dried and the roasted laver. Taurine was extracted about 1% from the dried and the roasted laver in the range of o~7o% ethyl alcohol concentration. The amount of carotenoids extracted by 95% ethyl alcohol from the dried and the roasted laver were 146.6 and 138.4mg%, respectively, which was 66 ~ 80% of yield extracted by methanol/acetone(1/1) solvent. The browning value of 50 ~6o% ethyl alcohol extraction group from roasted laver was highest among water/ethyl alcohol extraction group. The extraction yield was maximum when laver was extracted with water, and the value was 26.3% for the dried laver and 27.5% for the roasted layer. Organoleptic characteristics from four kinds of extraction groups containing hot water extraction showed that extracts from the roasted laver were evaluated most eminent and thought to be applicable to various preparation of food.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.501-504
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• 2000

The purification of a thermostable esterase expressed in Escherichia coli was investigated using thermoprecipitation of unclarified cell homogenates followed by after applying the heat-treated lysate to phenyl-sepharose column, and elution with detergent. Heat treatment at $70^{cdot}C$ was capable of removing to E. coli proteins. Specially, the thermoprecipitation with 15% polyethylene glycol 8000 can remove host proteins and nucleic acids efficiently. Various detergents were used to recover the esterase, which was strongly bound to phenyl-sepharose resin. Triton X-100, non-ionic detergent, was found to be the most efficient of all tested detergents.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.407.2-407.2
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• 2002

We have been studing sensitive non-enzymatic chemiluminescence (CL) imaging methods for the detection of DNA. For one of our methods, a unique chemical derivatization reagent. 3'. 4', 5'-trimethoxyphenylglyoxal (TMPG) was utilized. This reagent reacted specifically with guanine bases in nucleic acids to quickly produce a chemiluminescent derivative under mild reaction conditions. (omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.2
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• pp.65-83
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• 1978

This study was attempted to evaluate the taste of broiled-dried sea mussel which is a traditional dried Sea food in Korea. The contents of such compounds as free amino acids, nucleotides and their related compounds, TMAO, betaine, and nonvolatile organic acids were analysed. From the results of analysis of nucleotides, the contents of AMP and ADP in broiled-dried Mytilus coruscus and Mytilus edulis appeared higher than other nucleotides and tended to increase slightly after cooking, drying, and storage which might be due to both their stability and the addition of degradation of nucleic acids during cooking. In the free amino acid composition of fresh samples abundant amino were taurine, glycine, serine, glutamic acid, alanine, arginine, threonine, tyrosine, lysine and valine in order. Such amino acids as histidine, leucine, methionine and isoleucine were poor and both proline and phenylalanine were merely trace. The free amino acid composition in the extract of Mytilus corucus and Mytilus edulis after broil-drying was not changed. These amino acids, taurine, glycine, feline, glutamic acid, alanine and arginine were abundant in dried samples as well as in the fresh. The total free amino acid was greatly reduced after cooking and drying ranging from $76.3\%$ to $79.7\%$ loss to that of tile fresh. The content of betaine shelved the same tendency as in total free amino acid while TMA slightly increased relating to TMAO decrease during broil-frying. Such nonvolatile organic acids as succinic, lactic, malic and fumaric acid were abundant in both fresh and broiled-dried samples whereas oxalic and pyruvic acid were poor. It is found that the taste compounds of broiled-dried Mytilus coruscus and Mytilus edulis were composed of amino acids as glycine, serine, alanine, glutamic acid, arginine, and betaine, TMAO, ADP, AMP, and organic acids such as succinic acid, lactic acid, malic acid and fumaric acid. No significant differences in the taste compounds between male and female as well as between Mytilus coruscus and Mytilus edulis was not observed.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.161-164
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• 1991

A rapid and accurate method is described for the determination of nucleo-bases in rumen micro-organisms. A procedure to satisfactorily hydrolyse the micro-organisms involving reaction with a mixture of readily volatile organic acids (acetic and formic acids) under high pressure, is proposed, and optimal conditions for an analytical procedure with reversed phase HPLC is described. The following nucleobases contents (mmol/kg DM) of rumen micro-organisms were found: Adenine (Ade), 82.62; Guanine (Gua), 61.34; Cytosine (Cyt), 84.61; Thymine (Thy), 35.74; Uracil (Ura), 68.62; Hypoxanthine (Hxn), 13.06; Xanthine (Xn), 8.35. Total purine-N content (g/kg N) of rumen micro-organisms were 99.60. The nucleic acid N content (g/kg N) of microbial isolates were: RNA-N, 109.9; DNA-N, 50.9.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.814-816
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• 2003

오늘날 핵산과 단백질의 결합체에 관한 자료가 PDB(Protein Data Bank)와 같은 공공 데이터베이스에 급속도로 증가되고 있고 하나하나의 자료 자체도 많은 양의 데이터를 가지고 있기 때문에 더 이상 수작업으로 이를 분석하기란 거의 불가능할 뿐 아니라 정확도에 많은 문제가 있다. 그래서 본 연구에서는 방대한 생물학 자료를 효율적으로 분석하기 위해 자동화된 알고리즘을 개발하여 수작업에 의존하던 기존방식을 개선하였다. 이 알고리즘으로 51개의 RNA와 단백질간의 결합구조로 구성된 Dataset과 129개의 DNA와 단백질 간의 결합구조로 구성된 Dataset 분석하여 각각의 경우에 있어서의 결합성향과 결합유형을 찾아내었다. 이러한 본 연구의 결과가 아직 구조가 밝혀지지 않은 단백질-핵산간의 결합부위를 예측하는 알고리즘 개발에 기초 자료로 이용될 수 있다. 신약을 개발하는 과정에서 표적단백질의 결합부위를 예측하는데 활용될 수 있을 것이다.

• KSBB Journal
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• v.15 no.1
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• pp.76-79
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• 2000

Complex, ill-defined mixtures of natural origin are often used as nutrients in the production of biological products through microbial fermentation. Product yields are affected by variation in these natural products. Yeast extract is a typical example of these natural products. Since it is a mixture of amino acids, peptides and nucleic acids, its composition is not well characterized. In this study, we investigated the properties of thiamine hydrochloride, riboflavin and pyridoxine hydrochlride in yeast extract by using a gel filtration chromatography, ion exchange chromatography and high performance liquid chromatography. Yeast extract solution was fractionated by gel filtration chromatography and ion exchange chromatography, and then, each fraction was analyzed by using a high performance liquid chromatography.

• Journal of information and communication convergence engineering
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• v.17 no.1
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• pp.49-59
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• 2019

Biosensors, which are analysis devices used to convert biological reactions into electric signals, are made up of a receptor component and a signal transduction part. Graphene quantum dots (GQDs) and carbon quantum dots (CQDs) are new types of carbon nanoparticles that have drawn a significant amount of attention in nanoparticle research. The unique features exhibited by GQDs and CQDs are their excellent fluorescence, biocompatibility, and low cytotoxicity. As a result of these features, carbon nanomaterials have been extensively studied in bioengineering, including biosensing and bioimaging. It is extremely important to find biomaterials that participate in biological processes. Biomaterials have been studied in the development of fluorescence-based detection methods. This review provides an overview of recent advances and new trends in the area of biosensors based on GQDs and CQDs as biosensor platforms for the detection of biomaterials using fluorescence. The sensing methods are classified based on the types of biomaterials, including nucleic acids, vitamins, amino acids, and glucose.