• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.597-604
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• 2014

$\small{D}$-Phenylglycine aminotransferase ($\small{D}$-PhgAT) from Pseudomonas stutzeri ST-201 is useful for enzymatic synthesis of enantiomerically pure $\small{D}$-phenylglycine. However, its low protein solubility prevents its application at high substrate concentration. With an aim to increase the protein solubility, the N-terminus of $\small{D}$-PhgAT was genetically fused with short peptides ($A_1$ ${\alpha}$-helix, $A_2$ ${\alpha}$-helix, and ALAL, which is a hybrid of $A_1$ and $A_2$) from a ferredoxin enzyme of a halophilic archaeon, Halobacterium salinarum. The fused enzymes $A_1$-$\small{D}$-PhgAT, $A_2$-$\small{D}$-PhgAT, and ALAL-$\small{D}$-PhgAT displayed a reduced pI and increased in solubility by 6.1-, 5.3-, and 8.1- fold in TEMP (pH 7.6) storage, respectively, and 5-, 4.5-, and 5.9-fold in CAPSO (pH 9.5) reaction buffers, respectively, compared with the wild-type enzyme (WT-$\small{D}$-PhgAT). In addition, all the fused $\small{D}$-PhgAT displayed higher enzymatic reaction rates than the WT-DPhgAT at all concentrations of L-glutamate monosodium salt used. The highest rate, $23.82{\pm}1.47$ mM/h, was that obtained from having ALAL-$\small{D}$-PhgAT reacted with 1,500 mM of the substrate. Moreover, the halophilic fusion significantly increased the tolerance of $\small{D}$-PhgAT in the presence of NaCl and KCl, being slightly in favor of KCl, where under the same condition at 3.5 M NaCl or KCl all halophilic-fused variants showed higher activity than WT-$\small{D}$-PhgAT.

• Asian-Australasian Journal of Animal Sciences
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• 제33권7호
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• pp.1167-1179
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• 2020

Objective: This study was conducted to fathom the underlying mechanisms of nutrition intervention and redox sensitive transcription factors regulated by Antrodia cinnamomea fermented product (FAC) dietary supplementation in broiler chickens. Methods: Four hundreds d-old broilers (41±0.5 g/bird) assigned to 5 groups were examined after consuming control diet, or control diet replaced with 5% wheat bran (WB), 10% WB, 5% FAC, and 10% FAC. Liver mRNA expression of antioxidant, inflammatory and lipid metabolism pathways were analyzed. Prostaglandin E2 (PGE₂) concentration in each group were tested in the chicken peripheral blood mononuclear cells (cPBMCs) of 35-d old broilers to represent the stress level of the chickens. Furthermore, these cells were stimulated with 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH) and lipopolysaccharide (LPS) to evaluate the cell stress tolerance by measuring cell viability and oxidative species. Results: Heme oxygenase-1, glutathione S-transferase, glutamate-cysteine ligase, catalytic subunit, and superoxide dismutase, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) that regulates the above antioxidant genes were all up-regulated significantly in FAC groups. Reactive oxygen species modulator protein 1 and NADPH oxygenase 1 were both rather down-regulated in 10% FAC group as comparison with two WB groups. Despite expressing higher level than control group, birds receiving diet containing FAC had significantly lower expression level in nuclear factor-kappa B (NF-κB) and other genes (inducible nitric oxide synthase, tumor necrosis factor-α, interleukin-1β, nucleotide-binding domain, leucine-richcontaining family, pyrin domain-containing-3, and cyclooxygenase 2) involving in inflammatory pathways. Additionally, except for 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase that showed relatively higher in both groups, the WB, lipoprotein lipase, Acetyl-CoA carboxylase, fatty acid synthase, fatty acid binding protein, fatty acid desaturase 2 and peroxisome proliferator-activated receptor alpha genes were expressed at higher levels in 10% FAC group. In support of above results, promoted Nrf2 and inhibited NF-κB nuclear translocation in chicken liver were found in FAC containing groups. H₂O₂ and NO levels induced by LPS and AAPH in cPBMCs were compromised in FAC containing diet. In 35-d-old birds, PGE₂ production in cPBMCs was also suppressed by the FAC diet. Conclusion: FAC may promote Nrf2 antioxidant pathway and positively regulate lipid metabolism, both are potential inhibitor of NF-κB inflammatory pathway.

• 한국수산과학회지
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• 제17권6호
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• pp.499-505
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• 1984

수산물을 이용한 레토르트파우치 식품제조의 기초자료를 얻기 위해 우리 나라에서 많이 생산되는 바지락을 원료로 레토르트파우치 조미바지락의 가공조건을 검토하고 저장중 품질안정성에 대하여 실험하였다. 가공조건은 원료 바지락을 $3\%$ 식염수에서 11시간 토사를 배출시켜 증자 탈각한 후 설탕 $3\%$, sorbitol $12\%$, 식염 $2.5\%$, 글루탐산나트륨 $0.5\%$의 혼합조미료를 살포혼합하여 $5^{\circ}C$에서 12시간 조미한 다음 30분간 예비건조 ($35{\sim}40^{\circ}C$)하고 훈액처리($10\%$ Smoke EZ 훈액, 30초)하여 가볍게 건조한 다음($35{\sim}40^{\circ}C$, 2.5hr) 레토르트파우치필름(polyester/nylon/unoriented polypropylene : $12{\mu}m/15{\mu}m/50{\mu}m,\;15{\times}17cm$) 주머니에 충전하고, 진공포장하여 열수순환식레토르트르써 $120^{\circ}C$ 12분간 가열살균한 다음 냉각하는 것이 좋았다. Smoke EZ 훈액처리는 제품의 색조와 풍미를 향상시키는 효과가 있었으며 산패방지효과도 있었다. 그리고 제품은 실온에서 120일간 품질이 안정하게 유지되었다.

• 한국식품영양과학회지
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• 제40권1호
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• pp.94-101
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• 2011

본 연구는 오징어 가공부산물인 내장에 koji를 첨가하여 속성 발효한 천연조미료 소재 개발을 목적으로 결과를 요약하면 다음과 같다. 휘발성 염기질소량과 trimethylamine은 대조군이 가장 급격하게 증가하였고, 식염이 많이 첨가될수록 서서히 증가하였다. pH는 대조군이 가장 급격한 변화를 보였으며, 식염이 많이 첨가될수록 pH의 변화량이 적었다. 반면, 산도는 pH 감소와 반비례하여 증가하였다. 아미노질소는 식염 5% 첨가군이 가장 짧은 기간에 최고값을 나타내었으며, 식염 10, 15% 첨가군은 식염 5% 첨가군과 비슷한 값을 보였으나 발효기간이 길어 적합하지 않았다. 따라서 이상의 결과를 고려할 때, 식염 5% 첨가군이 조미료를 만들기에 가장 적합하다고 판단하였다. 식염 5%의 농도에 14일 간 발효시킨 오징어 내장 발효생성물의 일반성분은 조단백이 가장 많았으며, 유리아미노산 조성은 단맛을 내는 아미노산인 alanine과 감칠맛을 내는 아미노산인 glutamic acid의 함량이 가장 많았다. 항산화와 항대장암 활성은 농도 의존적으로 증가하는 것을 확인하였으나, positive control에 비하여 활성이 떨어졌다. 관능검사 결과는 시판 천연조미료와 비교하여 관능적으로 큰 차이가 없었다. 이상의 결과를 고려할 때 오징어 내장 발효생성물은 천연조미료 등 식품첨가제로써 활용이 가능하다고 판단된다.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.300-307
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• 2010

This study examined the effects of the dietary inclusion of various concentrations of red ginseng byproduct (RB) and a mixture containing red ginseng byproduct, garlic extract, yeast and filler (CR) on the growth, body composition, serum chemistry, and lysozyme activity of juvenile olive flounder (Paralichthys olivaceus). Juvenile fish (n= 630) weighing 5.0 g were randomly distributed into 21 180 L flow-through tanks (30 fish/tank). Seven experimental diets were prepared in triplicate: a control diet without additive, and diets containing 0.5, 1 and 2% concentrations of RB (RB-0.5, RB-1, RB-2) and CR (CR-0.5, CR-1, CR-2) at the expense of wheat flour. After an 8-week feeding trial, serum chemistry and lysozyme activity of fish were measured. Mean weight gain was significantly higher in fish fed the control diet than in fish fed the RB and CR diets. The dietary inclusion of RB and CR reduced feed utilization. Mean serum glucose and triglyceride (TG) levels were higher in fish fed the control diet than in fish fed the other diets. Mean glutamate pyruvate transaminase (GPT) levels of fish fed the control and RB-2 diets were higher than those of fish fed the RB-0.5, RB-1, CR-1, and CR-2 diets. Mean lysozyme activity levels of fish fed the RB-0.5 and RB-1 diets were higher than those of fish fed the control and CR diets. The results of this study indicate that red ginseng byproduct may be utilized as an immunostimulant rather than as a growth promoter for juvenile olive flounder. Dietary inclusion of 0.5% red ginseng byproduct effectively improved serum glucose, GPT, TG, and lysozyme activity of the fish in this study.

• 한국미생물·생명공학회지
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• 제38권4호
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• pp.349-361
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• 2010

본 총설에서는 아미노산의 공업적 생산균인 Corynebacterium glutamicum의 탄소 대사 및 이와 관련된 총체적 조절 메커니즘에 대한 최근의 연구를 정리하였다. C. glutamicum의 산업적 발효을 위한 기질로서 사용되는 당밀은 주로 sucrose, glucose, fructose로 이루어져 있으며, 이들 당은 phosphotransferase system을 통해서 수송된다. C. glutamicum의 탄소 대사 특징은 glucose가 다른 당이나 유기산 등과 함께 존재할 때, glucose와 이러한 탄소원 들을 동시에 대사한다. 그러나 glucose/glutamate 혹은 glucose/ethanol 등의 혼합물에서 는 탄소원의 순차적 이용으로 인해 나타나는 diauxic growth 현상을 나타내며, 이러한 carbon catabolite repression(CCR) 현상은 E. coli나 B. subtilis 등에서 알려진 것과는 다른 독특한 분자적 메커니즘과 조절 circuits을 가지고 있음이 밝혀지고 있다. C. glutamicum의 CRP homologue인 GlxR은 acetate 대사를 포함하여 glycolysis, gluconeogenesis 및 TCA cycle 등을 포함하는 중심탄소대사 조절 뿐만 아니라, 다양한 세포 기능의 조절에 관여하는 총체적 조절 단백질로서의 역할이 제시되고 있다. C. glutamicum의 adenylate cyclase(AC)는 막과 결합된 class IIIAC 로서, 막 단백질의 특성상 아직 규명되어 있지 않은 세포 외부의 환경 변화에 대응하여 세포 내의 cAMP합성 수준을 조절할 수 있는 sensor로 추정할 수 있다. 특히 C. glutamicum의 경우 배지내 glucose 를 비롯한 탄소원과 cAMP 농도와의 관련성이 E. coli에서 알려진 교과서적 지식과는 상반되게 변화하는 경향을 보이고 있어, cAMP signaling에 의한 세포 내 regulatory network 등은 향후 풀어야 할 의문으로 남아있다. 탄소대사 조절의 최상위에 존재하며 global 조절자인 GlxRcAMP 복합체 이외에도 차상위 전사조절 단백질로서 RamB, RamA, SugR 등이 존재하여 다양한 탄소대사를 조절한다. 최근 들어서는 새로운 탄소원으로서 대두되고 있는 biomass 관련 기질들을 이용할 수 있는 C. glutamucum 균주 구축을 통하여 이용 기질의 범위를 확대시키고자 하는 연구 및 탄소 대사와 관련하여 L-lysine의 발효 수율 혹은 생산성을 향상시키고자 하는 다양한 분자적 균주 육종 연구 등이 수행되고 있다.

• Molecules and Cells
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• 제38권1호
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• pp.1-13
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• 2015

Recent technical developments have transformed how neuroscientists can probe brain function. What was once thought to be difficult and perhaps impossible, stimulating a single set of long range inputs among many, is now relatively straight-forward using optogenetic approaches. This has provided an avalanche of data demonstrating causal roles for circuits in a variety of behaviors. However, despite the critical role that neuropeptide signaling plays in the regulation of behavior and physiology of the brain, there have been remarkably few studies demonstrating how peptide release is causally linked to behaviors. This is likely due to both the different time scale by which peptides act on and the modulatory nature of their actions. For example, while glutamate release can effectively transmit information between synapses in milliseconds, peptide release is potentially slower [See the excellent review by Van Den Pol on the time scales and mechanisms of release (van den Pol, 2012)] and it can only tune the existing signals via modulation. And while there have been some studies exploring mechanisms of release, it is still not as clearly known what is required for efficient peptide release. Furthermore, this analysis could be complicated by the fact that there are multiple peptides released, some of which may act in contrast. Despite these limitations, there are a number of groups making progress in this area. The goal of this review is to explore the role of peptide signaling in one specific structure, the bed nucleus of the stria terminalis, that has proven to be a fertile ground for peptide action.

• 한국식품위생안전성학회지
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• 제37권1호
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• pp.21-28
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• 2022

본 연구에서는 국내산 돌미나리에서 GABA생성능이 있는 신규 유산균을 분리, 동정한 결과, Enteroccoccus casseliflavus로 확인되었다. 최근까지 Lactobacillus속과 같은 GABA 생성 유산균에 대한 보고는 많이 되고 있고, 일부 Enterococcs속 유산균도 보고되고 있으나 E. casseliflavus종에 대한 보고는 없었다. 따라서 본 연구에서는 E. casseliflavus PL05 균주에 대한 GABA 생성 최적 조건을 찾기 위하여 배지의 유형, 생육 온도, 초기 pH 조건, 배양 시간, MGS 농도 및 탄소원을 포함한 다양한 조건을 테스트하였다. PL05 균주는 MRS 혹은 TSB 배지보다 BHI 배지에서 생육이 잘 되었으며, 배지의 초기 pH는 7-9 조건에서 가장 생육이 왕성하였고, GABA 생성 조건 역시 유사한 결과로 확인되었다. GABA의 기질에 해당하는 MSG의 농도별 GABA 생성량을 조사한 결과, 7%에서 가장 높은 생성량을 나타내었으나 5%에서도 유사한 수준으로 확인되어 효율적인 측면에서 5%가 적합할 것으로 판단된다. 탄소원에 따른 생육 및 GABA 생성량은 말토오스를 사용하였을 때 가장 높은 것으로 확인되었고, 이러한 최적의 조건들로 최종 테스트를 진행한 결과, 24시간째 140.06±0.71 mM의 GABA가 생성되었고, 전환율은 78.95%로 확인되었다. 또한 반코마이신을 포함한 10개의 항생제에 대한 감수성을 조사한 결과 내성이 없는 것을 확인하였다.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.481-499
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• 2022

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/ F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose-galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.761-767
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• 2007

This study was conducted to determine the effects of exogenous zinc-metallothionein (Zn-MT) on anti-oxidative function and pork quality. After feeding a corn-soybean meal-based diet for two weeks, 48 pigs ($Duroc{\times}Landrace{\times}Chinese\;Black Pig$) were assigned randomly to four groups. Pigs in Group 1 were maintained under non-stress conditions, whereas pigs in Groups 2, 3 and 4 were aggressively handled for 25 min to produce stress. Pigs in Groups 1, 2, 3, and 4 received intramuscular administration of saline (control group; CON), 0 (negative control group; NCON), 0.8 (low dose group; LOW), and 1.6 (high dose group; HIGH) mg rabbit liver Zn-MT per kg body weight, respectively. Pigs were slaughtered at 3 and 6 h post-injection. Zn-MT treatment increased (p<0.05) the activities of superoxide dismutase (SOD) and glutathione-peroxidase (GSH-PX) while decreasing the concentration of malondialdehyde (MDA) in liver. These responses were greater (p<0.05) at 6 h than at 3 h post Zn-MT injection. Zn-MT treatment increased (p<0.05) hepatic SOD mRNA levels in a time and dose-dependent manner and decreased (p<0.05) serum glutamate-pyruvate transaminase and lactate dehydrogenase activities (indicators of tissue integrity). Zn-MT administration decreased (p<0.05) lactate concentration and increased (p<0.05) pH and water-holding capacity in the longissimus thorasis meat. Collectively, our results indicate that intramuscular administration of Zn-MT to pre-slaughter stressed pigs improved tissue anti-oxidative ability and meat quality.