• Journal of Life Science
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• v.20 no.11
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• pp.1625-1633
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• 2010

This study was carried out to investigate the physicochemical compositions and antioxidative effects of Eriobotrya japonoca Lindl (Loquat). The proximate compositions of the loquat leaf on a dry matter basis were 8.78% moisture content, 6.74% crude protein, 7.87% crude fat, 6.99% crude ash, 43.61% dietary fiber and 26.01% carbohydrate. In analysis of free amino acids, 16 kinds total amino acid components, 17 kinds of components were isolated from loquat. The essential amino acids contained in loquat leaf accounted for 50.15% of total amino acids, while the non-essential amino acids accounted for 49.85%. In analysis of total fatty acids, only 5 kinds of acid were detected: lauric acid, myristic acid, pentadecanoic acid, stearic acid and oleic acid. The contents of vitamin A, vitamin E and vitamin C were 0.039 mg%, 0.096 mg% and 0.575 mg%, respectively. The mineral contents of loquat leaf were greater in order of Zn

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.573-577
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• 2013

To extend the shelf-life of the domestic peach, a low dose UV-C irradiation (0~3.0 $kJ/m^2$) was treated and the changes of the major chemical components were investigated. The contents of polyphenols in UV-treated peaches were higher than that of control with the highest at 0.25 $kJ/m^2$ UV treatment. The contents of polyphenols of control and UV treatments were slightly reduced by storage period. The contents of flavonoid were not significantly different among the control and UV treatments. Detected free sugars of the control and UV treatments were fructose, glucose, maltose and sucrose. Sucrose content was higher than that of other free sugars and free sugar content increased during storage. And free sugar content was not significantly different between the control and UV treatments. The free amino acid content of the control and UV treatments were 115.38 mg% and 95.92~120.94 mg% respectively, but there was no significant difference between the control and UV treatments.

• Food Science and Preservation
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• v.9 no.1
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• pp.61-66
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• 2002

Chemical composition of fresh and dried leaves and stems and fresh and cured tubers of bacon (Polymnia sonchifolia) was investigated. The moisture content of fresh leaves, stems, and tubers was 83.38, 92.30 and 89.52%, and there of dried leaves and stems were 18.08 and 27.97% and that of cured tubers was 27.97%. The content of lipid, protein, soluble solid, ascorbic acids chlorophyll and tannin was higher in leaves of yacon than in stems of that. In fresh and cured yacon, the content of protein were 0.04% both of them, of lipid was 0.31 and 0.54%; of ash, 0.40 and 0.42%; of ascorbic acids 2.77 and 2.87 mg/100 g. The major minerals of leaves, stem, and tubers of bacon were P, K, and Mg. The major free sugars of leaves, stems and tubers of bacon were glucose and fructose and after curing all free sugars of tubers of bacon were increased. The most abundant free amino acid was isoleucine in the leaves, stem, and tubers of bacon. The content of beta-carotene was 9.01 $\mu\textrm{g}$/100g in fresh leaves and 107.87 $\mu\textrm{g}$/100 g in dried leaves, and 0.40 $\mu\textrm{g}$/100 g in fresh tubers of bacon and 055 $\mu\textrm{g}$/100 g in cured tubers.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.869-875
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• 1997

The chemical components of Korean pollens and pollen extracts were analysed to provide fundamental data for pollen processing and products development. The contents of crude protein, crude lipid, crude ash, crude fiber and carbohydrate of pollens were $14.0{\sim}22.3%,\;3.0{\sim}8.8%,\;2.2{\sim}3.3%,\;0{\sim}37.5%,\;and\;31.9{\sim}64.4%$ respectively, showing the specially high crude fiber content (37.5%) in Pine pollen. Almost all the carbohydrate, lipid, protein and ash components except fiber were extracted by water and n-hexane. Free sugars identified in water extracts $(10\;^{\circ}Bx)$ of pollens were fructose and glucose as major component and maltose as minor component. The proportions of three free sugars to total soluble solid content of Mixed, Acorn, and Pine water extracts were 73.6%, 85.4% and 47.7% respectively. Potassium and phosphorus content in pollens and pollen water extracts were high, but Ca, Na, Mg, Fe and Zn were not major mineral components. The essential amino acids such as leucine, phenylalanine, methionine, lysine, valine, isoleucine and threonine were contained richly in pollens and those were almost completely extracted by water. Vitamin $B_1$ and C were not detected, but only small amount of vitamin $B_2$ was detected in the pollens and pollen extracts tested. The essential fatty acids such as linoleic acid and linolenic acid were contained richly in pollens. The proportion of unsaturated fatty acids to total fatty acid content in Mixed, Acorn and Darae pollen except Pine was higher than 50%.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.431-434
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• 1995

Chemical composition of barley leaves of four varieties (Olbori, Suwon 298, Suwon 311 and Milyang 60) grown under the same environmental conditions at the same location was investigated. Barley leaf samples were collected on two weeks before heading period. The barley leaves contained $25{\sim}29%$ crude protein, $9.3{\sim}9.9%$ crude lipid, $9.3{\sim}11.2%$ ash, $1.3{\sim}1.8%$ ${\beta}$-glucan on dry matter basis. Chlorophyll contents of Olbori, Suwon 298, Suwon 311 and Milyang 60 were 951 mg%, 885 mg%, 866 mg%, 826 mg%, respectively. Mineral contents of barley leaves were not significantly different each other and potassium content was found to be the highest among all the minerals observed. Vitamin C contents of Olbori, Suwon 298, Suwon 311 and Milyang 60 were 328 mg%, 266 mg%, 278 mg% and 269 mg%, respectively. Free sugar contents of barley leaves were somewhat different and the glucose content was the highest among the free sugars, ranging from 5.70% to 8.35%. Besides glucose, fructose, sucrose and raffinose contents were also relatively higher than the other free sugars. In other oligosaccharides, 1-kestose($GF_2$) content was between 0.26% and 0.39% and a slight amount of 1-nystose($GF_3$) was also detected. Although aspartic acid, glutamic acid and serine were relatively higher content than the other free amino acids, the values were not consistent in different varieties.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.349-361
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• 2010

In this review, the current knowledge of the carbon metabolism and global carbon regulation in Corynebacterium glutamicum are summarized. C. gluamicum has phosphotransferase system (PTS) for the utilization of sucrose, glucose, and fructose. C. glutamicum does not show any preference for glucose when various sugars or organic acids are present with glucose, and thus cometabolizes glucose with other sugars or organic acids. The molecular mechanism of global carbon regulation such as carbon catabolite repression (CCR) in C. glutamicum is quite different to that in Gram-negative or low-GC Gram-positive bacteria. GlxR (glyoxylate bypass regulator) in C. glutamicum is the cyclic AMP receptor protein (CRP) homologue of E. coli. GlxR has been reported to regulate genes involved in not only glyoxylate bypass, but also central carbon metabolism and CCR including glycolysis, gluconeogenesis, and tricarboxylic acid (TCA) cycle. Therefore, GlxR has been suggested as a global transcriptional regulator for the regulation of diverse physiological processes as well as carbon metabolism. Adenylate cyclase of C. glutamicum is a membrane protein belonging to class III adenylate cyclases, thus it could possibly be a sensor for some external signal, thereby modulating cAMP level in response to environmental stimuli. In addition to GlxR, three additional transcriptional regulators like RamB, RamA, and SugR are also involved in regulating the expression of many genes of carbon metabolism. Finally, recent approaches for constructing new pathways for the utilization of new carbon sources, and strategies for enhancing amino acid production through genetic modification of carbon metabolism or regulatory network are described.

• Journal of Microbiology
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• v.42 no.4
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• pp.319-327
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• 2004

An additional amylase, besides the typical $\alpha-amylase,$ was detected for the first time in the cytoplasm of B. subtilis SUH4-2, an isolate from Korean soil. The corresponding gene (bbmA) encoded a malto­genic amylase (MAase) and its sequence was almost identical to the yvdF gene of B. subtilis 168, whose function was unknown. Southern blot analysis using bbmA as the probe indicated that this gene was ubiquitous among various B. subtilis strains. In an effort to understand the physiological function of the bbmA gene in B. subtilis, the expression pattern of the gene was monitored by measuring the $\beta-galactosidase$ activity produced from the bbmA promoter fused to the amino terminus of the lacZ struc­tural gene, which was then integrated into the amyE locus on the B. subtilis 168 chromosome. The pro­moter was induced during the mid-log phase and fully expressed at the early stationary phase in defined media containing $\beta--cyclodextrin\;(\beta-CD),$ maltose, or starch. On the other hand, it was kept repressed in the presence of glucose, fructose, sucrose, or glycerol, suggesting that catabolite repression might be involved in the expression of the gene. Production of the $\beta-CD$ hydrolyzing activity was impaired by the spo0A mutation in B. subtilis 168, indicating the involvement of an additional regu­latory system exerting control on the promoter. Inactivation of yvdF resulted in a significant decrease of the $\beta-CD$ hydrolyzing activity, if not all. This result implied the presence of an additional enzyme(s) that is capable of hydrolyzing $\beta-CD$ in B. subtilis 168. Based on the results, MAase encoded by bbmA is likely to be involved in maltose and $\beta-CD$ utilization when other sugars, which are readily usable as an energy source, are not available during the stationary phase.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2165-2172
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• 2017

Lignocellulose is now a promising raw material for biofuel production. However, the lignin complex and crystalline cellulose require pretreatment steps for breakdown of the crystalline structure of cellulose for the generation of fermentable sugars. Moreover, several fermentation inhibitors are generated with sugar compounds, majorly furfural. The mitigation of these inhibitors is required for the further fermentation steps to proceed. Amino acids were investigated on furfural-induced growth inhibition in E. coli producing isobutanol. Glycine and serine were the most effective compounds against furfural. In minimal media, glycine conferred tolerance against furfural. From the $IC_{50}$ value for inhibitors in the production media, only glycine could alleviate growth arrest for furfural, where 6 mM glycine addition led to a slight increase in growth rate and isobutanol production from 2.6 to 2.8 g/l under furfural stress. Overexpression of glycine pathway genes did not lead to alleviation. However, addition of glycine to engineered strains blocked the growth arrest and increased the isobutanol production about 2.3-fold.

• Food Science and Preservation
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• v.6 no.2
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• pp.233-238
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• 1999

This study was determined changes of components of sweet and astringent persimmon vinegars by two stages fermentation. Free sugars of persimmon juices before alcohol fermentation were mainly composed of glucose, fructose and sucrose. The content of glucose, fructose and sucrose of sweet persimmon juice was 6.60, 6.12 and 1.74%, respectively, and those of astringent persimmon was 5.63, 5.21, 0.62%, respectively. The contents of free sugar decreased continuously during fermentation. Major organic acids of persimmon juices were acetic, galacturonic, malic, citric and ascorbic acid. Alcohols of persimmon juices was detected methanol, ethanol, iso-propylalcohol, n-propylalcohol and iso-butylalcohol at the initial fermentation. The contents of alcohols increased continuously up to 4days of fermentation but their contents except ethanol decreased slightly at 5th day of fermentation. Contents of free amino acid were higher in sweet persimmon than those in astringent persimmon. Volatile components increased during acetic acid fermentation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.344-350
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• 2006

Thermoplasma acidophilum is a thermoacidophilic archaeon that grows optimally at $59^{\circ}C$ and pH 2. Along with another thermoacidophilic archaeon, Sulfolobus solfataricus, it is known to metabolize glucose by the non-phosphorylated Entner-Doudoroff (nED) pathway. In the course of these studies, the specific activities of glyceraldehyde dehydrogenase and glycerate kinase, two enzymes that are involved in the downstream part of the nED pathway, were found to be much higher in T. acidophilum than in S. solfataricus. To characterize glycerate kinase, the enzyme was purified to homogeneity from T. acidophilum cell extracts. The N-terminal sequence of the purified enzyme was in exact agreement with that of Ta0453m in the genome database, with the removal of the initiator methionine. Furthermore, the enzyme was a monomer with a molecular weight of 49kDa and followed Michaelis-Menten kinetics with $K_m$ values of 0.56 and 0.32mM for DL-glycerate and ATP, respectively. The enzyme also exhibited excellent thermal stability at $70^{\circ}C$. Of the seven sugars and four phosphate donors tested, only DL-glycerate and ATP were utilized by glycerate kinase as substrates. In addition, a coupled enzyme assay indicated that 2-phosphoglycerate was produced as a product. When divalent metal ions, such as $Mn^{2+},\;CO^{2+},\;Ni^{2+},\;Zn^{2+},\;Ca^{2+},\;and\;Sr^{2+}$, were substituted for $Mg^{2+}$ the enzyme activities were less than 10% of that obtained in the presence of $Mg^{2+}$. The amino acid sequence of T. acidophilum glycerate kinase showed no similarity with E. coli glycerate kinases, which belong to the first glycerate kinase family. This is the first report on the biochemical characterization of an enzyme which belongs to a member of the second glycerate kinase family.