• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.45-49
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• 1998

Two kinds of Mutants of Corynebacterium glutamicum, which were resistant to branched chain amino acid analogues, were obtained for L-leucine production; C. glutamicum LT26 resistant to 4-azaleucine and $\alpha$-amino-$eta$-hydroxyvaleric acid, and from which C. glutamicum LT3811-70 resistant to DL-4-thiaisoleucine were derived. Accumulation of L-leucine in the culture broths of these mutant strains, C. glutamicum LT26 and LT3811-70, were much higher than those of their parent strains even though they were non-auxotrophic mutants. Enzymatic analyses were performed to measure the activities of $\alpha$-acetohydroxy acid synthase (AHAS) and $\alpha$-isopropylmalate synthase (IPMS), which were the key enzymes for the L-isoleucine, L-valine and L-leucine biosynthetic pathways branching from a common precursor. In C. glutamicum LT26 and LT3811-70, AHAS and IPMS were found to be derepressed and desensitized to L-leucine. In addition, in C. glutamicum LT3811-70, IPMS was further more derepressed by L-leucine and AHAS was more desensitized by L-isoleucine and L-valine compared to its parent strain, C. gIEitamicum LT26.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.200-205
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• 2001

The effects of dietary supplementation with the sodium salt of isobutyric acid in a low protein (10% CP) wheat straw based diet on nutrient utilization, blood metabolites and growth performance were studied with male crossbred calves. The calves were divided into two equal groups of 6 each. The animals of the control group were fed a basal diet consisting of wheat straw, concentrate mixture and green oat fodder in 40:40:20 proportion whereas BCFA supplemented group received the basal diet+isobutyric acid at 0.75 percent of basal diet. The duration of study was 120 days. The feed intake between experimental groups did not differ significantly and the average total DMI (% BW) was 1.99 and $1.95kg\;day^{-1}$ in control and BCFA supplemented diets. The dietary supplementation of BCFA improved (p<0.01) the DM, OM, CP (p<0.05), NDF and cellulose digestibilities by 8.50, 9.01, 5.39, 17.78 and 18.44 per cent over those fed control diet. The total N retention on BCFA supplementation was improved (p<0.01) due to the decreased (p<0.05) faecal N excretion. The BCFA supplementation did not alter the blood circulatory levels of glucose, total protein, albumin, urea N and amino acids. However after 120 days of experimental feeding a significant (p<0.05) increase in the concentrations of non-esterified fatty acid was observed in control group. The DCP intake and the DCP content of experimental diets was similar in both groups. However, the TDN content of BCFA supplemented diet was significantly (p<0.01) higher (64.35%) than that of control (59.60%). The total live weight gain in BCFA supplemented diet increased by 15.94% over control. The average daily gain and efficiency of feed conversion were also improved in BCFA fed calves by 13.38 and 26.71% respectively, compared to control. It is concluded that dietary supplementation with isobutyric acid improved the digestibility of nutrients and growth performance of calves.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.2
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• pp.43-49
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• 2018

Maple syrup urine disease (MSUD, OMIM#248600) is a rare and autosomal recessively-inherited metabolic disorder that is caused by mutations in the branched-chain ${\alpha}$-ketoacid dehydrogenase (BCKDH) genes. It prevents the normal breakdown of branched-chain amino acids (BCAAs), such as leucine, isoleucine, and valine, and leads to poor feeding, lethargy, abnormal movements, seizure, and death if untreated. Here, we report the case of a Korean newborn of biochemically- and genetically-confirmed MSUD manifesting lethargy and central apnea, the acute state of which was successfully treated. The molecular genetic investigation revealed two novel heterozygous mutations (p.Ala32Phefs*48 and p.Val 130Phe) in BCKDHB, and both parents were confirmed as carriers. We emphasize the importance of early diagnosis and prompt introduction of specific treatment for MSUD in life saving and prognosis.

• Animal Bioscience
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• v.35 no.7
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• pp.1030-1038
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• 2022

Objective: Two experiments were conducted to evaluate the effect of enzyme complex (EC) on the standardized ileal digestibility (SID) of amino acids (AA) in corn gluten meal (60%) (CGM), soy protein concentrate (SPC), dried bovine plasma (DBP), and poultry offal meal (POM). Experiments I and II were conducted with broilers in the pre-starter (1 to 7 days of age) and starter (1 to 21 days of age) phases, respectively. Methods: The treatments consisted of a protein-free diet (PFD) containing feedstuffs either supplemented with EC (xylanase, amylase, and protease) or not. In Experiment I, a total of 360 one-day-old male Cobb-500 broiler chicks were randomly housed in 45 pens, resulting in five replicates with eight birds each, totalizing eight treatments and one PFD group. In Experiment II a total of 270 one-day-old male Cobb-500 broiler chicks were randomly housed in 45 pens, resulting in five replicates with six birds each, totalizing eight treatments and one PFD group. The PFD groups were used to assess the endogenous AA losses. The birds were slaughtered to collect the ileal content. Results: In the pre-starter phase, the SID of arginine, branched chain-aminoacids, glycine, serine, aspartate, and glutamic acid increased with EC addition. The EC improved the SID of arginine and glutamic acid of CGM; the SID of valine and cystine of SPC; the SID of leucine, glycine, and aspartate of POM and the SID of isoleucine of DBP. In the starter phase, the SID of isoleucine, phenylalanine and glycine increased in EC-supplemented diets. The EC improved the SID of isoleucine of DBP; the SID of phenylalanine of CGM and POM. The SID of AA of SPC was not influenced by the EC. Conclusion: The addition of an EC to broiler pre-starter and starter diets is efficient in increasing the SID of AA on SPC, POM, and DBP.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1916-1927
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• 2018

Corynebacterium glutamicum is an excellent platform for the production of amino acids, and is widely used in the fermentation industry. Most industrial strains are traditionally obtained by repeated processes of random mutation and selection, but the genotype of these strains is often unclear owing to the absence of genomic information. As such, it is difficult to improve the growth and amino acid production of these strains via metabolic engineering. In this study, we generated a complete genome map of an industrial L-valine-producing strain, C. glutamicum XV. In order to establish the relationship between genotypes and physiological characteristics, a comparative genomic analysis was performed to explore the core genome, structural variations, and gene mutations referring to an industrial L-leucine-producing strain, C. glutamicum CP, and the widely used C. glutamicum ATCC 13032. The results indicate that a 36,349 bp repeat sequence in the CP genome contained an additional copy each of lrp and brnFE genes, which benefited the export of L-leucine. However, in XV, the kgd and panB genes were disrupted by nucleotide insertion, which increase the availability of precursors to synthesize L-valine. Moreover, the specific amino acid substitutions in key enzymes increased their activities. Additionally, a novel strategy is proposed to remodel central carbon metabolism and reduce pyruvate consumption without having a negative impact on cell growth by introducing the CP-derived mutant $H^+$/citrate symporter. These results further our understanding regarding the metabolic networks in these strains and help to elucidate the influence of different genotypes on these processes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.91-101
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• 2022

In this study, we analyzed the compositional characteristics of Melosira nummuloides mass-cultured using Jeju lava seawater. M. nummuloides showed the highest growth rate when cultured for 14 days at 17-20℃ and 15,000 lx. Proximate composition of raw-material (RM) and freeze-dried M. nummuloides (FM) showed high ash content (65-72%), while ethanol-extracted M. nummuloides (EM) had low ash and high lipid contents. The predominantly occurring mineral, Si, was 334 g/kg in RM and 269 g/kg in FM, but EM contained only 1.97 g/kg. The ratio of essential amino acids was similar in RM (38.93%) and FM (36.89%) lower in EM (17.83%), but branched chain amino acids required for muscle metabolism was high (63.40%). The polyunsaturated fatty acids of EM (34.74%) was 11% more than that in RM (23.81%), and the ratio of omega-6 to omega-3 fatty acids was 1:3.6. Furthermore, the concentration of total chlorophyll was higher by 5.15 times (62.32 mg/g) and that of fucoxanthin by 7.06 times (11.02 mg/g) in EM than in RM (12.11, 1.56 mg/g, respectively). The mass cultivation and filtration of M. nummuloides using lava seawater has high prospects of commercialization as a competitive bio silica, cosmetic and healthy functional food material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1075-1082
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• 2000

본 논문에서는 게껍질분말 급여에 의한 천연 타우린 강화우유의 생산 가능성을 평가하고자 25두의 젖소를 5군으로 나누고, 각기 대조사료, 1%(1%CS), 3%(3%CS) 및 5% 게껍질분말사료(5%CS), 그리고 formaldehyde로 처리되 3% 게껍질분말사료 (3%FCS)를 30일간 급여하였다. 게껍질분말 단백질의 아미노산조성은 phenylalanine이 가장 높았고, glutamate, aspartate, glycine, serine histidine, arginine의 순으로 나타났으며, 다른 동물조직의 단백질과는 달리 branched-chain 아미노산의 함량이 비교적 낮았다. 게껍질에 함유된 유리아미노산 중 타우린은 가장 고농도로 존재하였으며, 특히 집게다리껍질에 509$\mu$mol/100 g이 함유되어 등뚜껑(319$\mu$mol/100g) 및 게껍질분말(296 $\mu$mol/100 g)에 비해 월등히 그 함량이 높았다. 게껍질분말의 급여가 우유의 타우린농도에 미치는 영향을 평가한 결과 p<0.01 수준에서 유의성이 관찰되었다. 1%CS군의 원유에는 5.84$\pm$0.73 $\mu$mole/100mL의 타우린이 함유되어 대조구 (4.84$\pm$0.29 $\mu$mol/100mL)에 비해 20%정도 더 높았으며, 3%CS군의 원유에는 7.21$\pm$0.77$\mu$mole/100 mL의 타우린이 함유되어 대조구에 비해 49%정도 유의적으로 증가하였다.(p<0.01). 한편, 3%FCS군의 경우 원유의 타우린농도가 3%CS군에 비해 유？거으로 감소하였고, 따라서 게껍질의 formaldehyde 처리는 반추위내에서 타우린을 보호하는데 효과적이지 못한 것으로 나타났다. 본 논문은 게껍질 급여에 의해 우유의 타우린농도가 증가하였음을 밝히는 최초의 보고이며, 본 연구의 결과는 앞으로 기타 축산제품의 타우린함량을 증가시키는데 폭넓게 응용되어질 수 있을 것이다.

• Genes and Genomics
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• v.40 no.11
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• pp.1157-1167
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• 2018

Sulfolobus species can grow on a variety of organic compounds as carbon and energy sources. These species degrade glucose to pyruvate by the modified branched Entner-Doudoroff pathway. We attempted to determine the differentially expressed genes (DEGs) under sugar-limited and sugar-rich conditions. RNA sequencing (RNA-seq) was used to quantify the expression of the genes and identify those DEGs between the S. acidocaldarius cells grown under sugar-rich (YT with glucose) and sugar-limited (YT only) conditions. The functions and pathways of the DEGs were examined using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Quantitative real-time PCR (qRT-PCR) was performed to validate the DEGs. Transcriptome analysis of the DSM 639 strain grown on sugar-limited and sugar-rich media revealed that 853 genes were differentially expressed, among which 481 were upregulated and 372 were downregulated under the glucose-supplemented condition. In particular, 70 genes showed significant changes in expression levels of ${\geq}$ twofold. GO and KEGG enrichment analyses revealed that the genes encoding components of central carbon metabolism, the respiratory chain, and protein and amino acid biosynthetic machinery were upregulated under the glucose condition. RNA-seq and qRT-PCR analyses indicated that the sulfur assimilation genes (Saci_2197-2204) including phosphoadenosine phosphosulfate reductase and sulfite reductase were significantly upregulated in the presence of glucose. The present study revealed metabolic networks in S. acidocaldarius that are induced in a glucose-dependent manner, improving our understanding of biomass production under sugar-rich conditions.

• Biomolecules & Therapeutics
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• v.29 no.4
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• pp.419-426
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• 2021

In this study, we aimed to investigate the effects of 8 weeks of treatment with a combination of evogliptin and leucine, a branched-chain amino acid, in mice with high-fat diet (HFD)-induced diabetes. Treatment with evogliptin alone or in combination with leucine reduced the body weight of the mice, compared to the case for those from the HFD control group. Long-term treatment with evogliptin alone or in combination with leucine resulted in a significant reduction in glucose intolerance; however, leucine alone did not affect postprandial glucose control, compared to the case for the mice from the HFD control group. Furthermore, the combination of evogliptin and leucine prevented HFD-induced insulin resistance, which was associated with improved homeostasis model assessment for insulin resistance, accompanied by markedly reduced liver fat deposition, hepatic triglyceride content, and plasma alanine aminotransferase levels. The combination of evogliptin and leucine increased the gene expression levels of hepatic peroxisome proliferator-activated receptor alpha, whereas those of the sterol regulatory element-binding protein 1 and stearoyl-CoA desaturase 1 were not altered, compared to the case in the HFD-fed mice (p<0.05). Thus, our results suggest that the combination of evogliptin and leucine may be beneficial for treating patients with type 2 diabetes and hepatic steatosis; however, further studies are needed to delineate the molecular mechanisms underlying the action of this combination.