• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.300-306
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• 1993

Speries-related meat flavors were investigated for red meats (bovine, porcine, caprine, and ovine). Volatile branched-chain fatty acids (VBCFAs) including 2-methylbutanoic, 3-methylbutanoic, 4-methylpentanoic, 2-ethylhexanoic, 4-methylhexanoic, 4-methyloctanoic, 6-methyloctanoic, 4-ethyloctanoic, 4-methylnonanoic, and 2-ethyldecanoic acids were identified in the meats from cow (bovine), pig (porcine), goats (caprine ; American white goat and Korean black goat), and lamb (ovine). Beef flavor of bovine meat was characterized by the basic meaty flavor, lacking in goaty and muttony flavor impacts due to low or absent in 4-methyl.octanoic and 4-ethyloctanoic acids. Porcine meat contained the least number of VBCFAs among sample species tested, and 3-methylbutanoic acid contributed to the unclean sweaty odor of pork. Caprine meat from Korean black and American white goats lacked in short VBCFAs (C5, C6, and C7) and contained 4-methyloctanoic and 4-ethyloctanoic acids contributing to the characteristic goaty flavor of caprine meat. Caprine meat flavor was distinctively characterized by 4-ethyloctanoic acid, while 4-methyloctanoic acid provides sweaty-muttony flavor to ovine meat. Although kinds of VBCFAs are same in two different varieties of caprine meats, meat sample from Korean black goat had stronger goaty odor and contained higher concentration of 4-ethyloctanoic acid than the meat sample from American white goat did.

• Tribology and Lubricants
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• v.17 no.2
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• pp.109-115
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• 2001

The lubricating performance of 23 kinds of polyol ester base oils 〔POEs〕 having different branch shapes was investigated by using a four ball tribometer under boundary lubrication condition. All the polyol ester base oils used in this study were made up of polyhydric alcohols of two-four valence and normal or branched fatty acids of different carbon number. The wear characteristics of polyol ester base oils are different from those of mineral oil, strongly affected by the branch shapes of fatty acids in their molecles. In particular, the polyol ester base oils having normal fatty acids such as n-octanoic acid, n-nonanoic acid etc. show much better wear performance than POEs having branched fatty acids such as 2-ethylhexanoic acid, 3,5,5-trimethyl hexanoic acid, etc. As the carbon chain length of normal fatty acids, in case of POEs of normal fatty acids, is increased, their wear rate is decreased and, in case of POEs of branched fatty acids, as the degree of branch of branched fatty acids is decreased, their wear rate is decreased. All the wear results of polyol ester base oils could be reasonably explained by comparing cohesive ability among fatty acid molecules in adsorption film by fatty acids obtained as POEs were decomposed.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1590-1597
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• 2017

Objective: This study aims to identify the relationship between odd- and branched-chain fatty acids (OBCFAs) and microbial nucleic acid bases in the rumen, and to establish a model to accurately predict microbial protein flow by using OBCFA. Methods: To develop the regression equations, data on the rumen contents of individual cows were obtained from 2 feeding experiments. In the first experiment, 3 rumen-fistulated dry dairy cows arranged in a $3{\times}3$ Latin square were fed diets of differing forage to concentration ratios (F:C). The second experiment consisted of 9 lactating Holstein dairy cows of similar body weights at the same stage of pregnancy. For each lactation stage, 3 cows with similar milk production were selected. The rumen contents were sampled at 4 time points of every two hours after morning feeding 6 h, and then to analyse the concentrations of OBCFA and microbial nucleic acid bases in the rumen samples. Results: The ruminal bacteria nucleic acid bases were significantly influenced by feeding diets of differing forge to concentration ratios and lactation stages of dairy cows (p<0.05). The concentrations of OBCFAs, especially odd-chain fatty acids and C15:0 isomers, strongly correlated with the microbial nucleic acid bases in the rumen (p<0.05). The equations of ruminal microbial nucleic acid bases established by ruminal OBCFAs contents showed a good predictive capacity, as indicated by reasonably low standard errors and high R-squared values. Conclusion: This finding suggests that the rumen OBCFA composition could be used as an internal marker of rumen microbial matter.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.172-175
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• 1994

Xanthomonas campestris M12 carrying OCT plasmid which could dissimilate octane was able to utilize n-alkanes of eight to sixteen carbon atoms via the capacity of this plasmid. M12 strain could utilize terminal oxidation products of these primary, alkanes, alcohols, aldehydes and fatty acids but not hexanoic acid, adipic acid, pimelic acid and heptanal. This strain also biodegraded n-alkanes by monoterminal or diterminal oxdation of straight-chain fatty acids, and branched-chain alkane.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.9-17
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• 2018

To investigate the role of bkdR, sigL, yplP, and des genes which were known to be involved in fatty acid synthesis and sensitive at low temperature, deletion mutants of Bacillus subtilis CU1065 and JH642 were constructed. To determine the low temperature sensitivity of these genes, we compared the growth curves of cells at $37^{\circ}C$ and $15^{\circ}C$. At $37^{\circ}C$, wild type and deletion mutants showed almost similar growth but only bkdR deletion strain at $15^{\circ}C$ showed very slow growing compared with wild type. At $15^{\circ}C$ sigL and yplP deletions were somewhat slower or similar to those of wild type strain. Double and triple mutants for bkdR, sigL, yplP deletions were constructed and grown at $20^{\circ}C$ in LB agar to investigate cold sensitive growth. Double or triple deletions including bkdR deletion showed cold sensitive growing. In order to identify more clearly cold sensitive growth, the experiments were carried out under cold shock conditions in which the temperature was lowered from $37^{\circ}C$ to $15^{\circ}C$ at the point of 0.4 optical densities at 600 nm. In these cold shock experiments, only bkdR deletion showed significantly lower growing and additional des deletion increases cold sensitivity. The bkdR activates the bkd operon, which catabolized isoleucine, valine and leucine, amino acids and produce precursors for the synthesis of branched fatty acids. At cold shock growing of bkdR deletion strain, isoleucine recovered cold sensitivity of bkdR deletion but valine did not restore cold sensitivity. Isoleucine is used as a precursor for the synthesis of anteiso-branched fatty acids. On the other hand, valine is used as a precursor for the synthesis of iso-branched fatty acids. This indicates that anteiso-branched fatty acid plays an important role at the cold shock condition.

• Journal of Nutrition and Health
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• v.36 no.6
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• pp.577-588
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• 2003

Severe protein-calorie malnutrition, common in patients with advanced liver disease, can seriously undermine the capacity for regeneration and functional restoration of liver. Nutritional supplementation for these patients can improve biochemical and hormonal abnormalities. However, these effects were not identified in patient with nonalcoholic liver cirrhosis. To determine effects of nutritional supplementation in patients with nonalcoholic liver cirrhosis, 77 subjects aged 29 to 69 years participated in this study for 12 weeks and were subdivided into three groups; normal diet group (Control group, n ＝ 16), branched-chain amino acid supplementation group (BCAA group, n ＝ 31), nutritional supplementation group (NS group, n ＝ 30). Anthropometric parameters, hemoglobin, hematocrit, blood cell counts, serum levels of lipids, vitamins, minerals and fatty acid composition, and plasma amino acids were examined. The mean values of age and height, and the initial values of weight and body mass index (BMI) were not different among all groups. After 12 weeks, there were no significant changes in these values in Control group. Only NS group showed significant increases in weight, lean body mass, midarm circumference, triceps skinfold thickness. Serum transferrins were increased both in BCAA and NS groups. Plasma levels of branched-chain amino acids, urea amino acids and glutamic acid were also significantly increased in these groups, but plasma levels of ammonia, serum LDL cholesterol and atherogenic index were decreased. However, there were no significant changes in serum levels of vitamin and mineral and composition of fatty acids in phospholipids in these groups. These results showed that the nutritional supplementation for patients with nonalcoholic liver cirrhosis can more improve nutritional status in these people together with increases of weight, body fat and lean body mass, compared to only BCAA supplementation. To ascertain and investigate the appropriate nutritional supplementation for patients with nonalcoholic liver cirrhosis, further studies are necessary.

• Animal Bioscience
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• v.34 no.7
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• pp.1134-1145
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• 2021

Objective: This study aimed to investigate the effect of dietary supplementation with Allium mongolicum Regel extracts on the growth performance, carcass characteristics, fat color, and concentrations of three branched-chain fatty acids related to flavor in ram lambs. Methods: Sixty 3-month-old, male, small-tailed Han sheep were selected and randomly allocated into four groups in a randomized block design. Four feeding treatments were used: i) a basal diet without supplementation as the control group (CK); ii) the basal diet supplemented with 10 g/lamb/d Allium mongolicum Regel powder as the AMR group; iii) the basal diet supplemented with 3.4 g/lamb/d Allium mongolicum Regel water extract as the AWE group; and iv) the basal diet supplemented with 2.8 g/lamb/d Allium mongolicum Regel ethanol extract as the AFE group. Results: The results demonstrated that the dry matter intake was lower for the AFE group than that in other groups (p = 0.001). The feed conversion ratio was greater for the AFE than that in other groups (p = 0.039). Dietary supplementation with Allium mongolicum Regel powder and its extracts decreased the concentrations of 4-methyloctanoic acid (MOA) (p<0.001), 4-ethyloctanoic acid (EOA) (p<0.001), and 4-methylnonanoic acid (MNA) (p = 0.044) in perirenal adipose tissue compared to those observed in the CK lambs. Dietary supplementation with Allium mongolicum Regel powder and its extracts decreased the concentrations of MOA (p<0.001) and EOA (p<0.001) in dorsal subcutaneous adipose tissue compared to those in the CK lambs. The concentrations of MOA (p<0.001) and EOA (p = 0.002) in omental adipose tissue were significantly affected by treatment, although there was a tendency for lower MNA (p = 0.062) in AMR, AWE, and AFE lambs than that in CK lambs. Conclusion: This study demonstrated that Allium mongolicum Regel and its extracts could significantly promote feed efficiency, although dry matter intake decreased and could decrease the MOA and EOA concentrations related to characteristic flavor and odor of body fat in lambs, except for tail adipose tissue.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.261-266
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• 1993

A new methyltrophic bacterium which utilizes methanol as a sole source of carbon and energy was isolated from soil. It was Gram-negative, nonmotile, nonspore-forming rod, and strictly aerobic bacterium. Catalase and oxidase activities were present. Nitrate was reduced to nitrite. Vitamins and other growth factors were not required. Generation time was 1.6 hr under the optimal condition. The isolate assimilated methanol via the ribulose mono-phosphate pathway (Enter-Doudoroff varient) and did not have .alpha.-ketoglutarate dehydrogenase. It assimilated ammonia through glutamate dehydrogenase. The guanine plus cytosine content of the DNA was 61.0 mol%. The celular fatty acid composition was primarily straight-chain saturated $C^{16 : 0}$ acids (palmitic acids) and unsaturated $C_{16 :1}$ acid (palmitoleic acids), and the isolate also contained two unidentified $C_{17}$ branched fatty acids. The major ubiquinone was Q-8, and Q-6 and Q-7 were present as minor components. Phosphatidylethanolamine and phosphatidylglycerol were predominantly present, and diphosphatidyglycerol was also detected. Based on the physiological and biochemical properties, the isolate was assigned to a novel species of the genus Methylobacillus, Methylobacillus methanolovorus sp. nov.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.523-528
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• 2013

This study investigates the effects of three branched-chain amino acids (BCAA; valine, leucine, and isoleucine) on the in vitro ruminal fermentation of wheat straw using batch cultures of mixed ruminal microorganisms. BCAA were added to the buffered ruminal fluid at a concentration of 0, 2, 4, 7, or 10 mmol/L. After 72 h of anaerobic incubation, pH, volatile fatty acids (VFA), and ammonia nitrogen ($NH_3$-N) in the ruminal fluid were determined. Dry matter (DM) and neutral detergent fiber (NDF) degradability were calculated after determining the DM and NDF in the original material and in the residue after incubation. The addition of valine, leucine, or isoleucine increased the total VFA yields ($p{\leq}0.001$). However, the total VFA yields did not increase with the increase of BCAA supplement level. Total branched-chain VFA yields linearly increased as the supplemental amount of BCAA increased (p<0.001). The molar proportions of acetate and propionate decreased, whereas that of butyrate increased with the addition of valine and isoleucine (p<0.05). Moreover, the proportions of propionate and butyrate decreased (p<0.01) with the addition of leucine. Meanwhile, the molar proportions of isobutyrate were increased and linearly decreased (p<0.001) by valine and leucine, respectively. The addition of leucine or isoleucine resulted in a linear (p<0.001) increase in the molar proportions of isovalerate. The degradability of NDF achieved the maximum when valine or isoleucine was added at 2 mmol/L. The results suggest that low concentrations of BCAA (2 mmol/L) allow more efficient regulation of ruminal fermentation in vitro, as indicated by higher VFA yield and NDF degradability. Therefore, the optimum initial dose of BCAA for in vitro ruminal fermentation is 2 mmol/L.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.724-735
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• 2023

NdgR, a global regulator in soil-dwelling and antibiotic-producing Streptomyces, is known to regulate branched-chain amino acid metabolism by binding to the upstream region of synthetic genes. However, its numerous and complex roles are not yet fully understood. To more fully reveal the function of NdgR, phospholipid fatty acid (PLFA) analysis with gas chromatography-mass spectrometry (GC-MS) was used to assess the effects of an ndgR deletion mutant of Streptomyces coelicolor. The deletion of ndgR was found to decrease the levels of isoleucine- and leucine-related fatty acids but increase those of valine-related fatty acids. Furthermore, the defects in leucine and isoleucine metabolism caused by the deletion impaired the growth of Streptomyces at low temperatures. Supplementation of leucine and isoleucine, however, could complement this defect under cold shock condition. NdgR was thus shown to be involved in the control of branched-chain amino acids and consequently affected the membrane fatty acid composition in Streptomyces. While isoleucine and valine could be synthesized by the same enzymes (IlvB/N, IlvC, IlvD, and IlvE), ndgR deletion did not affect them in the same way. This suggests that NdgR is involved in the upper isoleucine and valine pathways, or that its control over them differs in some respect.