• Archives of Pharmacal Research
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• 제27권5호
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• pp.570-575
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• 2004

2-Hydroxymuconic semialdehyde (2-HMS) dehydrogenase catalyzes the conversion of 2-HMS to 4-oxalocrotonate, which is a step in the meta cleavage pathway of aromatic hydrocarbons in bacteria. A tomC gene that encodes 2-HMS dehydrogenase of Burkholderia cepacia G4, a soil bacterium that can grow on toluene, cresol, phenol, or benzene, was overexpressed into E. coli HB 101, and its gene product was characterized in this study. 2-HMS dehydrogenase from B. cepacia G4 has a high catalytic efficiency in terms of V$_{max}$K$_{max}$ towards 2-hydroxy-5-methyl-muconic semialdehyde followed by 2-HMS but has a very low efficiency for 5-chloro-2-hydroxymuconic semialdehyde. However, the enzyme did not utilize 2-hydroxy-6-oxo-hepta 2,4-dienoic acid and 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid as substrates. The molecular weight of 2-HMS dehydrogenase from B. cepacia G4 was predicted to be 52 kDa containing 485 amino acid residues from the nucleotide sequence of the tomC gene, and it exhibited the highest identity of 78% with the amino acid sequence of 2-HMS dehydrogenase that is encoded in the aphC gene of Comamonas testosteroni TA441. 2-HMS dehydrogenase from B. cepacia G4 showed a significant phylogenetic relationship not only with other 2-HMS dehydrogenases, but also with different dehydrogenases from evolutionarily distant organisms.sms.

• 한국연초학회지
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• 제14권1호
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• pp.48-56
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• 1992

This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.

• 한국미생물·생명공학회지
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• 제13권2호
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• pp.119-127
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• 1985

여러 가지 Escherchia coli 변이주의, glucose 와 ammonium염과 같은 간단한 기질로부터 방향족 아미노산 특히 phenylanine을 생합성하는 능력을 비교 검토한 결과 방향족 아미노산 생합성과정중 common pathway의 첫 번째 반응이 phenylanine 생합성에 가장 큰 영향을 준다는 것을 확인하였다. 따라서 관계효소인 DAHP synthase의 효소활성과 생합성에 관련된 각종 대사 제어작용을 효과적으로 제거시킴으로서 phenylalanine 생산량을 크게 높일 수 있었으며 더욱이 phenylalanine terminal pathway의 첫 단계 반응을 촉매하는 prephenate de-hydratase의 효소활성과 효소생합성에 관련된 제어 작용도 동시에 제거하면 phenylalanine생산이 상승적으로 증가됨을 보였다. 한편 방향족아미노산의 transport system에 관계하는 arop유전자의 변이는 phenylalanine생산을 크게 저하시키는 효과를 나타내었다.

• Applied Biological Chemistry
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• 제17권1호
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• pp.63-80
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• 1974

한국산유자(韓國産柚子)의 화학적성분(化學的成分)을 일반성분(一般成分)과 특수성분(特殊成分)으로 구분(區分)하여 일반성분(一般成分)이 관(關)하여는 시기별변화(時期別變化)를 특수성분(特殊成分)은 성숙기유자(成熟期柚子)에 관(關)하여 amino acid vitamin C, 유리당(遊離糖), 유기산(有機酸), 향성분(香成分)등을 분석(分析)하여 시기별성분(時期別成分) 변화(變化)가 식물생리(植物生理)에 미치는 영향(影響)과 식품(食品)의 효과적(效果的) 이용(利用)에 관(關)한 검토결과(檢討結果)는 다음과 같이 요약(要約)된다. 1. 과피(果皮)와 과육(果肉)의 시기별분석결과(時期別分析結果)는 과피율(果皮率)과 과육율(果肉率)를 비교(比較)할때 전자(前者)가 더 크며 지역적(地域的)으로 볼때는 과피율(果皮率)은 도서부(島嶼部)가 내륙지(內陸地)보다 더 크다. 2. 일반성분(一般成分)에 있어서 과피(果皮)에서는 3기(期)까지 수분함량(水分含豊)의 증가(增加)를 보이고 기후(其後) 일정상태(一定狀態)를 유지(維持)하며 조지방(粗脂肪), 섬유질(纖維質), 회분(灰分), 총산(總酸), 가용성무질소물(可溶性無蜜素物)등은 3기(基)까지 감소(減少)하며 환원당(還元糖)은 급증(急增)하고 섬유질(纖維質)과 총산(總酸)은 계속감소(繼續減少)를 보인다. 과육(果肉)에서는 3기(期)까지 수분(水分), 환원당(還元糖)이 증가(增加)하고 조지방(粗脂肪), 섬유질(纖維質), 회분(灰分), 조단백질(粗蛋白質), 가용성무질소물(可溶性無窒素物)등은 3기(期)까지 감소(減少)한다. 3 Vitamin C의 함량(含量)은 과육(果肉) 보다 과피(果皮)에 많고 일본산유자(日本産柚子) 보다 한국산유자(韓國産柚子)에 더 많었다. 4. 유리당(遊離糖)은 xylose, fructose, glucose, sucrose등 4종(種)이 분리검출(分離檢出)되었고 과육(果肉)보다 과피(果皮)에 더 많이함유(含有)되어 있었다. 5. 휘발성유기산(揮發性有機酸)의 함량(含量)은 과육(果肉)보다 과피(果皮)에 더 많고 과피(果皮)에 acetic acid, formic acid, n-valet acid등 3종(種)과 과육(果肉)에 formic acid, acetic acid, propionicacid 등 3종(種)이 분리(分離)되었다. 6. 비휘발성유기산(非揮發性有機酸)의 함량(含量)은 과피(果皮)보다 과육(果肉)에 더 많고 과피(果皮)에 citric acid, glutaric acid, malic acid tartaric acid, oxalic acid, malonic acid, succinic acid와 unknown 1종(種)등 8종(種)이 분리검출(分離檢出)되었고 과육(果肉)에서는 citric acid, malic acid, succinic acid, oxalic acid, glutaric acid, malonic acid등 6종(種)이 분리확인(分離確認)되있다. 7. 향성분(香成分)의 정유중성부(精油中性部)에서 D-limonene, ${\alpha}-pinone$, p-cymene의 3종(種)과 unknown 7종(種)등 10종(種)이 분리검색(分離檢索)되었고 함량(含量)으로 보아 D-limonene이 유자(柚子)의 주향성분(主香成分)인 것으로 생각된다. 8. 식품(食品)의 효율적이용(效率約利用)은 과피(果皮)와 과육(果肉)을 공(共)히 쓸수 있고 미숙과(未熟果)는 citric acid제조용(製造用), 성숙과(成熟果)는 과중제조원료(果汁製造原料)로 쓸수 있다는 것이 상기(上記) 연구결과(硏究結果)에의(依)하여 확인(確認)되었다.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1518-1522
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• 2012

Leuconostoc mesenteroides is a heterofermentative Grampositive bacterium that plays key roles in fermentation of foods such as kimchi, sauerkraut, and milk, leading to the production of various organic acids and aromatic compounds. To study the microbiological and genomic characteristics of L. mesenteroides, we have developed a new chemically defined minimal medium by using the single omission technique. During the exponential cell growth, this species required glutamine, methionine, valine, and nicotinic acid as essential nutrients and 8 amino acids (arginine, cysteine, histidine, leucine, phenylalanine, proline, threonine, and tryptophan), 5 vitamins (ascorbic acid, folic acid, inosine, calcium panthothenate, and thiamine), and others (manganese, magnesium, adenine, uracil, and Tween 80) as supplemental nutrients. This medium is useful to study the metabolic characteristics of L. mesenteroides and to explain its role in food fermentation.

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.247-253
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• 2002

Two experiments were conducted to investigate the impact of high temperature and dietary tryptophan (Trp) on performance, selected organ weights and plasma free amino acid (AA) concentrations in broiler chickens. In Experiment 1, exposure to $27-33^{\circ}C$ of chickens for 2 weeks from 2 weeks of age did not affect growth and plasma free AA concentration except for a decrease in the concentration of plasma tyrosine (Tyr). In Experiment 2, 2-week-old birds were allocated to one of three temperature treatments; $24^{\circ}C$ (control), $36^{\circ}C$ (heat stress, HS) and $24^{\circ}C$ pair-fed (24PF) for 2 weeks and fed on diets containing 50, 100 and 300% of NRC requirement for Trp. Heat stress caused a reduction of weight gain and feed intake irrespective of dietary Trp levels compared with control counterparts, while feeding of 300% Trp diet did not attenuate the reduced performance by HS exposure. In groups fed the 100% Trp diets, plasma aromatic AA (AAA) and Tyr concentrations were decreased in the HS birds compared with the 24PF group. Plasma concentrations in most of AA groups were increased by HS in chickens fed the 50% Trp diet, while those were not changed by HS in chickens fed the 300% Trp diet, compared with 24PF counterparts. The plasma Trp/LNAA (LNAA=large neutral AAs, which are comprised of BCAA, AAA and Trp) ratio was increased by HS in chickens fed the 100% Trp diet, while it was decreased in chickens fed on 50% Trp diet as compared with 24PF group. From these results, it is suggested that performance and plasma amino acid profile deranged by heat stress are modulated, at least, to be relieved from the heat stress by feeding 50% Trp diet but not at all by feeding 300% Trp diet. The involvement of altered plasma AA profiles, in particular plasma Tyr concentrations and Trp/LNAA ratio, is discussed in association with the performance characteristics of HS chickens.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8호
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• pp.1172-1185
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• 2019

Objective: Meat quality attributes in postmortem muscle tissues depend on skeletal muscle metabolites. The objective of this study was to determine the key metabolic compounds and pathways that are associated with postmortem aging and beef quality in Japanese Black cattle (JB; a Japanese Wagyu breed with highly marbled beef). Methods: Lean portions of Longissimus thoracis (LT: loin) muscle in 3 JB steers were collected at 0, 1, and 14 days after slaughter. The metabolomic profiles of the samples were analyzed by capillary electrophoresis time-of-flight mass spectrometry, followed by statistical and multivariate analyses with bioinformatics resources. Results: Among the total 171 annotated compounds, the contents of gluconic acid, gluconolactone, spermidine, and the nutritionally vital substances (choline, thiamine, and nicotinamide) were elevated through the course of postmortem aging. The contents of glycolytic compounds increased along with the generation of lactic acid as the beef aging progressed. Moreover, the contents of several dipeptides and 16 amino acids, including glutamate and aromatic and branched-chain amino acids, were elevated over time, suggesting postmortem protein degradation in the muscle. Adenosine triphosphate degradation also progressed, resulting in the generation of inosine, xanthine, and hypoxanthine via the temporal increase in inosine 5'-monophosphate. Cysteine-glutathione disulfide, thiamine, and choline increased over time during the postmortem muscle aging. In the Kyoto encyclopedia of genes and genomes database, a bioinformatics resource, the postmortem metabolomic changes in LT muscle were characterized as pathways mainly related to protein digestion, glycolysis, citric acid cycle, pyruvate metabolism, pentose phosphate metabolism, nicotinamide metabolism, glycerophospholipid metabolism, purine metabolism, and glutathione metabolism. Conclusion: The compounds accumulating in aged beef were shown to be nutritionally vital substances and flavor components, as well as potential useful biomarkers of aging. The present metabolomic data during postmortem aging contribute to further understanding of the beef quality of JB and other breeds.

• 한국식품저장유통학회지
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• 제30권2호
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• pp.287-299
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• 2023

효소 및 미생물 복합제를 사용하여 인비트로 발효 루왁커피를 제조하여 non-fermented coffee beans(NFC)과 fermented coffee beans(FC)의 커피 품질을 비교하였다. 총유리아미노산 함량은 NFC가 254.01±4.89 mg/mL, FC가 264.15±16.80 mg/mL로 FC의 함량이 다소 높은 것으로 확인되었다. 이때 NFC는 glutamic acid, γ-aminon-butyric acid 등이 높았으나, FC는 lysine, leucine, valine 등 필수아미노산의 함량이 높았다. 커피 생두의 발효과정은 sucrose의 감소와 fructose 및 glucose의 유의적인 증가를 가져왔다. 커피 추출물의 색도는 NFC에 비해 FC 시료에서 높은 명도(L)와 적색도(a) 및 황색도(b)를 보였다. 카페인 함량은 NFC 1,130.22±1.55 ㎍/mL, FC 696.94±0.04 ㎍/mL로써 발효 후 약 38%의 카페인이 감소되었다. 폴리페놀 및 클로로겐산 함량은 NFC에서 각각 2.31±0.01 mg GAE/mL와 531.81±27.32 ㎍/mL, FC에서 각각 2.03±0.07 mg GAE/mL와 264.46±2.47 ㎍/mL로 발효에 따라 떫은맛 관련 성분의 함량이 유의적으로 감소됨을 알 수 있었다. 전자코 분석에서 NFC와 FC의 휘발성 향성분의 차이가 뚜렷함이 확인되었고, methylethyl formate, 2-methyl-1, 3-cyclopentadiene, 2-chloro-2-methylbutane, 2-methylbutanal 등의 휘발성 화합물이 발효 후 높은 강도로 감지되었다. 관능 평가에서는 NFC 추출물보다 FC 추출물의 aroma, body, aftertaste, overall에서 높은 관능 평점을 보여주었다(p<0.001). 이상의 결과에서 효소 및 미생물 복합제를 사용한 커피 생두의 발효는 유효 성분들의 변화를 일으켜 커피 원두의 로스팅 과정 중 Maillard 반응을 촉진함으로써, 향미가 증가되고 카페인 함량이 감소된 인비트로 루왁 커피의 제조 가능성을 시사하였다.

• 한국식품영양학회지
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• 제22권3호
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• pp.416-420
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• 2009

A formula diet based on pork meat oligopeptides(pork meat protein hydrolysates) was designed for experimental hepatitic rats. The rats were given D-galactosamine for 6 days. During this period, the rats were provided with a 12% casein diet or the formula diet which was low in aromatic amino acids and rich in branched chain amino acids. The formula diet was prepared using pork meat oligopeptides as the principal nitrogen source. The hepatitic rats given the formula diet had lower plasma GOT and GPT concentrations. Additionally, the fischer ratio of the plasma was significantly lower in those rats. However, there was no significant difference in the plasma insulin-like growth factor-I concentration before and after acid-ethanol extraction among groups. These results suggest that the formula diet was better for the animals than the casein diet. Furthermore, these findings suggest that pork meat oligopeptides are an excellent material for preparation of formula diets for patients suffering from hepatitis.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.153-157
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• 2004

Tyrosine phenol-lyase (TPL) is a useful enzyme for the synthesis of pharmaceutical aromatic amino acids. In the current study, sequential DNA shuffling and screening were used to enhance the stability of TPL. Twenty-thousand mutants were screened, and several improved variants were isolated. One variant named A13V, in which the $13^{th}$ amino acid alanine was substituted by valine, exhibited a higher temperature and denaturant stability than the wild-type TPL. The purified mutant TPL, A13V, retained about 60% of its activity at $76^\circ{C}$, whereas the activity of the wild-type TPL decreased to less than 20% at the same temperature. Plus, A13V exhibited about 50% activity with 3 M urea, while the wild-type TPL lost almost all its catalytic activity, indicating an increased denaturant tolerance in the mutant A13V. It is speculated that the substitution of Val for the Ala in the $\beta$-strand of the N-terminal arm was responsible for the heightened stabilization, and that the current results will contribute to further research on the structural stability of TPL.