• 한국미생물·생명공학회지
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• 제48권1호
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• pp.1-11
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• 2020

The aim of this study was to investigate the effects of Torulaspora delbrueckii and Saccharomyces cerevisiae, as pure fermenters and mixed fermenters (simultaneous and sequential culture), on the production of non-volatiles and volatiles, and on the antioxidant activity in Golden Dried Longan juice and Golden Dried Longan wines. Alanine, arginine, glutamic acid, leucine, proline, and gamma-aminobutyric acid (GABA) were the most prominent amino acids that were found in these wines. The Golden Dried Longan Wine fermented with monocultures of S. cerevisiae and T. delbrueckii produced a total volatile aroma content of 393.21 mg/l and 383.20 mg/l, respectively. Simultaneous culture of the two organisms produced the highest total volatile aroma content, that affected most volatile compounds including isobutanol, ethyl acetate, ethyl decanoate, ethyl heptanoate, ethyl hexanoate, ethyl pentanoate, isoamyl acetate, and isobutyl acetate. Of the four treatments, the sequential culture possessed the highest total phenolic content (5.80 mg gallic acid equivalents (GAE)/ml). In addition, the total phenolic content significantly correlated with the antioxidant activity of the Golden Dried Juice and Golden Dried Longan Wine. These results suggest that co-cultures of the two organisms used in the production of the Golden Dried Longan Wine may improve the intensity and complexity of its aroma.

• Animal Bioscience
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• 제34권2호
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• pp.295-305
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• 2021

Objective: The objectives of this study were to compare the effects of normal and low protein content (PC) of starter diet supplemented or not with blends of branched-chain amino acids (BCAAs) on growth performance of broilers under summer conditions and to investigate whether these effects altered some quality traits and the characteristics of gastrointestinal tract. Methods: A total of 768 mixed-sex broiler chicks (Ross 308, one-d-old) with an average initial body weight (BW) of 47.6±1.03 g were allocated into six treatments with four replications in 2×3 factorial arrangement. Factors were: PC, normal (N, 22% to d 15); and low (L, 20% to d 15); and added BCAA blends, L-leucine, L-isoleucine, and L-valine at zero (0L:0I:0V); 1.0, 0.25, and 0.25 (4L:1I:1V); or 1.0, 0.25, 0.75 (4L:1I:3V) g/kg of diet. Hence, six dietary treatments were named as N0L:0I:0V, N4L:1I:1V, N4L:1I:3V, L0L:0I:0V, L4L:1I:1V, and L4L:1I:3V. Average indoor temperature and humidity were 32.8℃±1.7℃ and 61.1%±4.12%, respectively. Results: BW, feed conversion ratio (FCR) and carcass weight were not affected by PC, BCCA and their interaction (p>0.05). The L diets decreased the water holding capacity of the breast (p = 0.002) and thigh (p = 0.050) meats and dressing percentage (p = 0.005) compared to the N diets. The 4L:1I:1V diet decreased breast yield compared to the 0L:0I:0V diets (p = 0.041). The effect of PC on feed intake, mortality and gastrointestinal trait weight were depended on the L:I:V ratios under summer conditions due to interactions between factors (p<0.05). The FI and mortality of L4L:1I:1V broilers were lower than those of N4L:1I:1V birds (p<0.05). Conclusion: It was concluded that the blends of BCAAs used failed to improve performance and to promote breast yields, because diets with normal or with reduced protein supplemented or not with BCAAs up to d 15 produced a similar BW and FCR in broilers raised in hot-climate conditions.

• 한국축산식품학회지
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• 제42권1호
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• pp.46-60
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• 2022

In this study, angiotensin-I-converting enzyme inhibitory (ACEI) activity was evaluated in fermented goat milk fermented by lactic acid bacteria (LAB) from fermented foods and breast milk. Furthermore, the potential for ACEI peptides was identified in fermented goat milk with the highest ACEI activity. The proteolytic specificity of LAB was also evaluated. The 2% isolate was inoculated into reconstituted goat milk (11%, w/v), then incubated at 37℃ until pH 4.6 was reached. The supernatant produced by centrifugation was analyzed for ACEI activity and total peptide. Viable cell counts of LAB and titratable acidity were also evaluated after fermentation. Peptide identification was carried out using nano liquid chromatography mass spectrometry (LC-MS/MS), and potential as an ACEI peptide was carried out based on a literature review. The result revealed that ACEI activity was produced in all samples (20.44%-60.33%). Fermented goat milk of Lc. lactis ssp. lactis BD17 produced the highest ACEI activity (60.33%; IC₅₀ 0.297±0.10 mg/mL) after 48 h incubation, viable cell counts >8 Log CFU/mL, and peptide content of 4.037±0.27/mL. A total of 261 peptides were released, predominantly derived from casein (93%). The proteolytic specificity of Lc. lactis ssp. lactis BD17 through cleavage on the amino acid tyrosine, leucine, glutamic acid, and proline. A total of 21 peptides were identified as ACEI peptides. This study showed that one of the isolates from fermented food, namely Lc. lactis ssp. lactis BD17, has the potential as a starter culture for the production of fermented goat milk which has functional properties as a source of antihypertensive peptides.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.17-20
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• 2001

The effect of chicken IGF-I on protein synthesis of chicken embryo myoblasts cultured in serum-free medium was examined. When myoblasts were expanded to approximate 20-30% of well, the medium was changed to the serum-free medium including 0, 2, 20, 200 or 2000 ng/ml of recombinant chicken IGF-I. The culture medium including 10% fetal calf serum (FCS) was used as positive control. After 1 day of incubation, protein synthesis was measured by the incorporation of [$^3H$]-L-leucine. Thereafter cells were continued to incubate for further 18 hours, and the radioactivity in the protein was measured as an index of protein synthesis. The values for protein synthesis cultured in the serum-free medium without chicken IGF-I or with 2000 ng/ml of chicken IGF-I were the lowest. Protein synthesis was elevated with increasing chicken IGF-I concentration from 0 to 20 ng/ml. The values for protein synthesis in the 20 ng/ml and 200 ng/ml IGF-I groups were about half of that of the FCS group. The present study revealed that the potency of chicken IGF-I at the levels of 20 to 200 ng/ml to stimulate myoblast protein synthesis was about half of that of 10% FCS.

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.709-715
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• 2016

The objective of the research was to determine the chemical composition as well as the physicochemical properties of the longissimus muscle from Korean entire and castrate elk. Twelve elk stags were raised and fed on concentrate with ad libitum hay. All animals were equally divided into castrated and non-castrated (entire) males, and slaughtered at 5 year of age. It was found that entire elk, in comparison with castrate elk, had higher content of moisture and lower content of fat (p<0.05). Compared with entire males, the castrates had lower pH and shear force values (p<0.05). However, castrates had higher $L^*$, $a^*$, and $b^*$ values compared with entires (p<0.05). An analysis of the fatty acid profile revealed that the muscles of entire and castrate elk had the most abundant concentrations of the following fatty acids: palmitic acid (C16:0) of the saturated fatty acid, and oleic acid (C18:1n-9) of the unsaturated fatty acid. The entire elk contains higher proportions of linoleic acid (C18:3n6), eicosenoic acid (C20:1n9), and arachidonic acid (C20:4n6) (p<0.05). Cholesterol content in elk was not affected by castration. The predominant free amino acid was glutamic acid related to umami taste. It is apparent that the castrate animals carried higher content of histidine, isoleucine, and leucine than those of the entire group (p<0.05). In this study, it was concluded that venison quality of elk is affected by castration and these results can provide fundamental information for venison production.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.952-959
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• 2007

His-His-Leu (HHL), a tripeptide derived from a Korean soybean paste, is an angiotensin-I-converting enzyme (ACE) inhibitor. We report here a method of producing this tripeptide efficiently by expressing tandem multimers of the codons encoding the peptide in E. coli and purifying the HHL after hydrolysis of the peptide multimers. The HHL gene, tandemly multimerized to a 40-mer, was ligated with ubiquitin as a fusion gene (UH40). UH40 was inserted into vector pET29b; the UH40 fusion protein was then produced in E. coli BL21. The recombinant UH40 protein was purified by cation-exchange chromatography with a yield of 17.3mg/l and analyzed by matrixassisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry and protein N-terminal sequencing. Leucine aminopeptidase was used to cleave a 405-Da HHL monomer from the UH40 fusion protein and the peptide was purified using reverse-phase high-performance liquid chromatography (HPLC) on a C18 HPLC column, with a final yield of 6.2mg/l. The resulting peptide was confirmed to be HHL with the aid of MALDI-TOF mass spectrometry, glutamine-TOF mass spectrometry, N-terminal sequencing, and measurement of ACE inhibiting activity. These results suggest that our production method is useful for obtaining a large quantity of recombinant HHL for functional antihypertensive peptide studies.

• 한국식품저장유통학회지
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• 제21권6호
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• pp.908-916
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• 2014

가수량이 120%에서 300%로 증가하면서 pH는 4.6에서 4.2로 산도는 6.0에서 5.2로, 아미노산도는 6.0에서 2.5로, 가용성 고형분 함량은 18.4에서 $7.4^{\circ}Brix$로 낮아졌다. 술덧의 알코올 농도는 150%에서 17.6%로 가장 높았고 알코올 생산수율은 각각 59.7, 74.5, 80.8, 82.8, 89.4, 90.6%로 가수량에 의존적으로 증가하였다. 술덧의 유기산 총량은 각각 207.85, 222.38, 222.06, 204.56, 194.34, 204.34 mg/100 mL로 150%와 180%에서 높게 나타났다. 유리아미노산 총량은 각각 474.60, 317.32, 241.89, 244.51, 189.00, 208.12 mg/100 mL로 가수량에 의존적으로 감소하였고 arginine, alanine, glutamic acid, glycine, isoleucine, leucine, lysine, phenylalanine, proline, serine, tyrosine, valine이 주요 성분이었다. Iso-butanol은 154.88~182.62 ppm, iso-amylalcohol은 320.59~394.47 ppm, 1-propanol은 91.50~170.91 ppm, 2-phenylalcohol은 108.93~144.26 ppm농도로 분포하고 있고 ethyl acetate, acetaldehyde, furfural, butyric acid가 검출되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1419-1429
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• 2012

A series of studies were carried out to investigate the supplemental effects of dietary garlic extracts (GE) on whole body amino acids, whole body and muscle free amino acids, fatty acid composition and blood plasma changes in 6 month old juvenile sterlet sturgeon (Acipenser ruthenus). In the first experiment, fish with an average body weight of 59.6 g were randomly allotted to each of 10 tanks (two groups of five replicates, 20 fish/tank) and fed diets with (0.5%) or without (control) GE respectively, at the level of 2% of fish body weight per day for 5 wks. Whole body amino acid composition between the GE and control groups were not different (p>0.05). Among free amino acids in muscle, L-glutamic acid, L-alanine, L-valine, L-leucine and L-phenylalanine were significantly (p<0.05) higher in GE than in control. However, total whole body free amino acids were significantly lower in GE than in control (p<0.05). GE group showed higher EPA (C22:6n3) and DHA (C22:5n3) in their whole body than the other group (p<0.05). In the second experiment, the effects of dietary garlic extracts on blood plasma changes were investigated using 6 month old juvenile sterlet sturgeon averaging 56.5 g. Fish were randomly allotted to each of 2 tanks (300 fish/tank) and fed diets with (0.5%) or without (control) GE respectively, at the rate of 2% of body weight per day for 23 d. At the end of the feeding trial, blood was taken from the tail vein (n = 5, per group) at 1, 12, and 24 h after feeding, respectively. Blood plasma glucose, insulin and the other serological characteristics were also measured to assess postprandial status of the fish. Plasma glucose concentrations (mg/dl) between two groups (GE vs control) were significantly (p< 0.05) different at 1 (50.8 vs 62.4) and 24 h (57.6 vs 73.6) after feeding, respectively, while no significant difference (p>0.05) were noticed at 12 h (74.6 vs 73.0). Plasma insulin concentrations (${\mu}IU$/ml) between the two groups were significantly (p<0.05) different at 1 (10.56 vs 5.06) and 24 h (32.56 vs 2.96) after feeding. The present results suggested that dietary garlic extracts could increase dietary glucose utilization through the insulin secretion, which result in improved fish body quality and feed utilization by juvenile sterlet sturgeon.

• 한국식품저장유통학회지
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• 제24권7호
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• pp.1043-1051
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• 2017

본 연구는 각 지역의 생막걸리에서 분리된 야생 효모의 다앙한 발효학적 특성을 조사하기 위해 34종을 수집하고 효모를 분리, 동정하였다. 야생효모는 62 균주로 분리되었고, 26S rDNA 염기서열을 분석한 결과, Saccharomyces cerevisiae와 Pichia kudriavzevii로 동정 되었다. 62개의 균주들 중 발효학적 특성이 우수한 균주들을 선발하기 위해 황화수소와 $CO_2$ 생성능, 알코올 내성, 응집성 및 향기 성분 생성능을 분석하였다. 알코올 내성과 $CO_2$ 생성능의 상관성을 확인하기 위해 주성분분석(Principal Components Analysis)을 하였다. PC1 양의 방향에 강하게 부하되는 균주는 YM37, YM31, YM32, YM22로 분석되었으며, 총 0.14-0.18 g/72 h의 $CO_2$ 생성으로 대조군에 비해 높은 발효능을 보였고, 이들 중 YM22를 제외하고 불쾌취인 황화수소를 생성하지 않았다. 또한 이 4개의 균주들은 알코올 내성 15% 이상을 보유하며, 응집성은 0.5-1.0 mL 사이인 flocculation type으로 확인되었다. API 분석 및 cerulenin, TFL 저항성을 실험한 결과, 향기성분 생성능이 좋은 효모는 황화수소와 알코올 내성, 응집성 실험에서 우수한 발효학적 특성을 보인 YM37, YM31, YM32, YM22를 포함한 총 33개로 확인되었다. 이러한 결과를 통해 우리나라 생막걸리에서 분리한 야생 효모의 알코올 발효 및 향미 특성을 확인하였으며, 분리된 야생 효모는 주류 제조의 종균 효모로 이용 가능성을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.238-246
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• 2015

A unicellular red microalga was isolated from environmental freshwater in Korea, and its morphological, molecular, and biochemical properties were characterized. Morphological analysis revealed that the isolate was a unicellular biflagellated green microalga that formed a non-motile, thick-walled palmelloid or red aplanospore. To determine the taxonomical position of the isolate, its 18S rRNA and rbcL genes were sequenced and phylogenetic analysis was performed. We found that the isolate was clustered together with other related Haematococcus strains showing differences in the rbcL gene. Therefore, the isolated microalga was classified into the genus Haematococcus, and finally designated Haematococcus sp. KORDI03. The microalga could be cultivated in various culture media under a broad range of pH and temperature conditions. Compositions of the microalgal cellular components were analyzed, and its protein, carbohydrate, and lipid compositions were estimated to be 21.1 ± 0.2%, 48.8 ± 1.8%, and 22.2 ± 0.9%, respectively. In addition, D-glucose and D-mannose were the dominant monosaccharides in the isolate, and its amino acids were composed mainly of aspartic acid, glutamic acid, alanine, and leucine. Moreover, several polyunsaturated fatty acids accounted for about 80% of the total fatty acids in Haematococcus sp. KORDI03, and the astaxanthin content in the red aplanospores was estimated to be 1.8% of the dry cell weight. To the best of our knowledge, this is the first report of an Haematococcus sp. isolated from Korea, which may be used for bioresource production in the microalgal industry.