• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1581-1588
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• 2018

The growth of lactic acid bacteria (LAB) generates a high number of metabolites related to aromas and flavors in fermented dairy foods. These microbial proteases are involved in protein hydrolysis that produces necessary peptides for their growth and releases different molecules of interest, like bioactive peptides, during their activity. Each genus in particular has its own proteolytic system to hydrolyze the necessary proteins to meet its requirements. This review aims to highlight the differences between the proteolytic systems of Streptococcus thermophilus and other lactic acid bacteria (Lactococcus and Lactobacillus) since they are microorganisms that are frequently used in combination with other LAB in the elaboration of fermented dairy products. Based on genetic studies and in vitro and in vivo tests, the proteolytic system of Streptococcus thermophilus has been divided into three parts: 1) a serine proteinase linked to the cellular wall that is activated in the absence of glutamine and methionine; 2) the transport of peptides and oligopeptides, which are integrated in both the Dpp system and the Ami system, respectively; according to this, it is worth mentioning that the Ami system is able to transport peptides with up to 23 amino acids while the Opp system of Lactococcus or Lactobacillus transports chains with less than 13 amino acids; and finally, 3) peptide hydrolysis by intracellular peptidases, including a group of three exclusive of S. thermophilus capable of releasing either aromatic amino acids or peptides with aromatic amino acids.

• 한국식품과학회지
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• 제8권3호
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• pp.129-135
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• 1976

대맥(大麥) 16개(個) 품종(品種)(단백질함량(蛋白質含量) 최고(最高) 15.4%에서 최저(最低) 6.1%)의 정맥중(精麥中) amino산(酸)의 조성(組成)과 이들 상호간(相互間) 및 이들과 단백질(蛋白質)과의 상관(相關) 관계(關係)는 다음과 같았다. 1) 제한(制限) amino 산(酸)은 lysine 이었으며 threonine과 tyrosine이 적고 leucine과 phenylalanine이 특히 많은 편이며 필수(必須) amino산(酸) 총량(總量)은 많은 편이다. 2) 단백질(蛋白質)은 단백질당(蛋白質當) amino산(酸) 함량(含量)과의 상관(相關)에서 lysine, arginine, total basic amino acid와 1%수준에서 threonine, alanine 및 aspartic acid와 5%수준에서 유의부상관(有意負相關)을, phenylalanine과 1%수준에서 proline, cystine과 5%수준에서 유의정상관(有意正相關)을 갖는다. 3) Lysine은 arginine 및 aspartic acid가 유의정상관(有意正相關)을 보이므로 대맥(大麥)에서도 aspartic acid가 lysine 대사에 관련됨을 시사하며 다수성(多收性) 품종(品種) 또는 다비조건(多肥條件)은 aspartic acid pool을 상대적으로 감소시킬 가능성이 있고 그 결과로 lysine이 적어지는 것같다. 4) Lysine은 색소결합능(色素結合能)(Dye binding capacity)과 유의정상관(有意正相關)을 보였다. $(r=0.7377^{**})$ 5) Tryptophan은 histidine, 염기성 amino산총량(酸總量) 및 arginine 과만 유의정상관(有意正相關)을 보였다. 6) 필수(必須) amino산(酸) 중(中) lysine, tryptophan, threonine, valine은 같이 증감하며 함황(含黃) amino산(酸)과 방향성(芳香性) amino산(酸) 및 isoleucine, leucine은 이들과 반대로 증감한다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.280.2-280
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• 1997

No Abstract, See Full Text

• Natural Product Sciences
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• 제4권3호
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• pp.115-129
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• 1998

The chemical constituents and their biological activities of the sponge genus Dysidea has been reviewed.

• Journal of Microbiology
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• 제44권1호
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• pp.50-53
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• 2006

Cys-29 and Cys-251 of Streptomyces albus valine dehydrogenase(ValDH) were highly conserved in the corresponding region of $NAD(P)^+$-dependent amino acid dehydroganase sequences. To ascertain the functional role of these cysteine residues in S. albus ValDH, site-directed mutagenesis was performed to change each of the two residues to serine. Kinetic analyses of the enzymes mutated at Cys-29 and Cys-251 revealed that these residues are involved in catalysis. We also constructed mutant ValDH by substituting valine for leucine at 305 by site-directed mutagenesis. This residue was chosen, because it has been proposed to be important for substrate discrimination by phenylalanine dehydrogenase (PheDH) and leucine dehydrogenase (LeuDH). Kinetic analysis of the V305L mutant enzyme revealed that it is involved in the substrate binding site. However it displayed less activity than the wild type enzyme toward all aliphatic and aromatic amino acids tested.

• 생약학회지
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• 제32권1호통권124호
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• pp.49-54
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• 2001

The effects of protoberberine compounds on serotonin biosynthesis in P815 cells were investigated. Protoberberine compounds such as berberine, palmatine and coralyne decreased serotonin content dose-dependently, but coptisine did not. The $IC_{50}$ values of berberine, palmatine and coralyne were $3.0\;{\mu}M,\;16.5\;{\mu}M\;and\;14.5\;{\mu}M$, respectively. Protoberberine compounds at concentrations up to $20\;{\mu}M$ were not cytotoxic towards P815 cells. The activity of tryptophan hydroxylase, a ratelimiting enzyme in serotonin biosynthesis, was inhibited by the exposure of berberine, palmatine and coralyne in P815 cells (14.9-19.3% inhibition at $2-15\;{\mu}M$), but that of aromatic L-amino acid decarboxylase was not. These results suggest that the inhibition of tryptophan hydroxylase activity by berberine, palmatine and coralyne might partially contribute to the decrease in serotonin content in P815 cells.

• 한국토양비료학회지
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• 제21권3호
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• pp.301-306
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• 1988

벼와 보리짚을 부숙(腐熟)시키면서 경시적(經時的)으로 시료(試料)를 채취(採取)하여 부식산(腐植酸)을 추출정제(抽出精製)한 산가수분해(酸加水分解)한 용액중(溶液中)에 함유(含有)되어 있는 amino 산(酸)의 양(量)과 분포상태(分布狀態)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 부식산(腐植酸)의 가수분해액중(加水分解液中)에 함유(含有)되어 있는 amino 산(酸)은 종류(種類)에서나 그 분포상태(分布狀態)에서 볏짚과 보리짚에 따라 차이가 있었다. 2. 두 시료(試料) 공(共)히 중성(中性) amino 산(酸)이 가장 많이 함유(含有)되어 있었으며 산성(酸性) amino 산(酸)과 염기성(鹽基性) amino 산(酸)의 순서로 함유(含有)되어 있었다. 3. 단위부식산당(單位腐植酸當) 총(總) amino 산(酸)의 양(量)으로 볼 때 볏짚이 보리짚의 함량(含量)보다 많았다. 4. 부숙화(腐熟化)가 진행(進行)될수록 lysine의 양(量)은 증가(增加)한 반면 histidine의 양(量)은 감소(減少)했으며, glycine, glutamic acid, aspartic acid, alanine, leucine 등(等) 5가지의 amino 산(酸)이 전경우를 통해 주(主)된 성분(成分)이었다. 5. 부숙화(腐熟化)된 두 식물체(植物體)의 부식산(腐植酸)에는 arginine이 함유(含有)되어 있지 않았다. 6. phenylalanine과 tyrosine은 전시료(全試料)에서 검출되었으며 이들은 부식산(腐植酸)이 지니고 있는 aromaticity에 기여한다고 판단되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권12호
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• pp.1753-1761
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• 2013

The individual and interactive effects of Schisandra chinensis powder (SCP) and sodium nitrite additions on color, pH, water holding capacity, residual nitrite, 2-thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen, texture properties, fatty acids, amino acids and sensory evaluation of cooked pork sausages were investigated after 20 d of storage at $4^{\circ}C$. The powders (0, 0.5 and 1.0%) were added to sausages either alone or in combination with nitrite (0 and 100 ppm). SCP added-sausages showed lower $L^*$ (lightness) and W (whiteness) values, and higher $b^*$ (yellowness) values than sausage containing no nitrite, and exhibited the highest $a^*$ values at a 0.5% addition (p<0.05). Residual nitrite and TBARS values were found to be significantly reduced as the addition levels of SCP increased (p<0.05). As the addition of SCP increased, the sausage showed gradually decreased brittleness, cohesiveness, springiness, gumminess and chewiness, while adhesiveness increased. Polyunsaturated fatty acid, n-6 and n-6/n-3 fatty acid ratio concentrations were significantly higher in sausages containing SCP (p<0.05). The addition of SCP to sausage significantly (p<0.05) increased the ammonia content (by 0.5% SCP) and aromatic amino acid concentrations (by 1.0% SCP) (p<0.05). Inclusion of SCP in sausage meat resulted in a significant deterioration in quality characteristics of flavor, springiness, juiciness and overall acceptability (p<0.05). As expected, the observed changes in $a^*$, W, pH, shear force, texture property, TBARS, fatty acid, amino acid and sensory score of sausages, depended on the rate of addition of nitrite (p<0.05). These results suggest that SCP addition is not an effective way of improving the sensory evaluation of sausages, but may beneficially affect TBARS, nitrite scavenging activity, fatty acid and amino acid content in pork sausages.

• 한국염색가공학회지
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• 제8권2호
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• pp.64-70
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• 1996

Wool yarns were treated in dimethylformamide solutions containing various concntrations of three dibasic acid anhydrides: succinic, itaconic, and phthalic arthydrides in various conditions. The structurl aspects of these dibasic acid anhydries are different: succinic, itaconic, and phthalic acid arthydrides have saturated aliphatic ethylene, unsaturated aliphatic vinyl and aromatic phenyl one groups, respectively. The properties of acylated wool keratin are as follows: Decreasing amino group and increasing carboxyl group by acylation lowered the hydrophilic property, and then moisture regain, and decreased acid dye uptake and enhanced cationic dye uptake of wool keratin. In the case of phthalic acid anhydries, in spite of lowest acyl content, the minimum of moisture regain was resulted from the bulk benzen ring, occuping much more voids on wool keratin molecules than other reagents. Acid solubility was increased by the decrease of amino group and hydrogen bonding by acylation. Alkali solubility was also increased formation of new amide group on the side chain of keratin, which can be degraded easily by alkali. In the case of phthalic acid anhydride, the relative high solubility was resulted from the much higher molecular weight of dissolved fractions. The surface of wool keratin was not damaged by treatment with any acylating agent.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.668-676
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• 2001

Pseudomonas sp. strain SY5 is a PCB-degrading bacterium [24] that includes two different enzymes (BphC1 and BphC2) encoding 2,3-dihdroxybiphenyl 1,2-dioxygenase and BphD encoding 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase. The bphC1 and bphC2 genes were found to consist of 897 based encoding 299 amino acids and 882 bases encoding 294 amino acids, respectively, whereas the bphD gene consisted of 861 bases encoding 287 amino acids. According to a homology search, a 50% and 39% similarity between the bphC1 and bphC2 genes at the nucleotide and amino acid level was shown, respectively. The bphC1 gene showed a 38% and 45% similarity at the amino acid level to Alcaligenes eutrophus A5 and Rhodococcus rhodochrous, respectively, whereas, bphC2 showed a 95% and 43% similarity, respectively. A comparison of the deduced amino acid sequence of the bphD product of Pseudomonas sp. SY5 with that of A. eutrophus A5, Pseudomons sp. KKS102, and LB400 showed a sequence identity of 92, 92, and 79%, respectively. Strain SY5 was originally isolated from municipal sewage containing recalcitrant organic compounds an found to have a high degradability of various aromatic compounds [23]. The current study found that strain SY5 had two extradiol-type dioxygenases, which did not hybridize with each other as they had a low similarity, yet a similar structure of evolutionarily conserved amino acids residues for catalytic activity between BphC1 and BphC2 was observed.