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Yeo, In-Seok,Shim, Woo-Yong,Kim, Jung Hoe Elsevier 2018 Journal of biotechnology Vol.274 No.-
<P>For the biological production of L-ribulose, conversion by enzymes or resting cells has been investigated. However, expensive or concentrated substrates, an additional purification step to remove borate and the requirement for cell cultivation and harvest steps before utilization of resting cells make the production process complex and unfavorable. Microbial fermentation may help overcome these limitations. In this study, we constructed a genetically engineered Candida tropicalis strain to produce L-ribulose by fermentation with a glucose/L-arabinose mixture. For the uptake of L-arabinose as a substrate and conversion of L-arabinose to L-ribulose, two heterologous genes coding for L-arabinose transporter and L-arabinose isomerase, were constitutively expressed in C. tropicalis under the GAPDH promoter. The Arabidopsis thaliana-originated L-arabinose transporter gene (STP2)-expressing strain exhibited a high L-arabinose uptake rate of 0.103 g/g cell/h and the expression of L-arabinose isomerase from Lactobacillus sakei 23 K showed 30% of conversion (9 g/L) from 30 g/L of L-arabinose. This genetically engineered strain can be used for L-ribulose production by fermentation using mixed sugars of glucose and L-arabinose.</P>
( Yeong Bok Song ),( Boh Kyung Kim ),( Mi Jin Choi ),( Yeong Ok Song ),( Eun Ju Cho ) 부산대학교 김치연구소 2012 김치의 과학과 기술 Vol.15 No.-
The protective effects of L-arabinose and sugar beet (SBP) on high glucose-induced oxidative stress were investigated using LLC-PK cells. Under the high glucose-induced cellular oxdative model, the treatment of 45 mM of glucose led to the decrease in cell viability and increase in lipod peroxidation_However. L-arabinose and SBP significantly inhibited the high glucose-induced cytotoxicity and lipid per-oxidation. In addition, the formation of nitric oxide(NO) was increased by the treatment of 45mM glu-cose. while the treatment of L-arabinose or SBP inhibited signigicantly the NO formation compared with high glucose-treated control. The superoxide anion production of groups treated whth L-arabinose or SBP was significantly lower than that of the control treated with high glucose. Futhermore. L-arabinose and SBP elevated the glucose uptake. resulting in lower glucose concentration compared with non-treated control. High glucose levels induced the overexpressions of bax. inducible NO synthase and cyclooxygen-ase-2. but L-arabinose or SBP treatrnent down-regulated the expressions of these genes. Arabinose and SBP also inhibited the expression of nuclear factor-kappa B induced by 45mM glucose in LLC-PK cells. In particular, arabinose exhibited stronger inhibitory activities on high glucose-induced oxdative stress than SBP did. These findings indicate that L-arabinose and SBP are promising antioxidative agents with protective activities against hyperglycemia.
Angelo BAnARES,Grace NISOLA,Won-Keun LEE,Wook-Jin CHUNG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10
Existing engineered GA-producing strains have limited substrate consumption capacity as carbon catabolite repression (CCR) hinders the co-utilization of different sugars. Hence, in this study, Escherichia coli was engineered to co-utilize D-xylose and L-arabinose for GA production through the synergy of metabolic pathways responsible for the assimilation D-xylose and L-arabinose towards GA formation. Different L-arabinose metabolic pathways namely glycoptimus pathway and L-xylulose-1-phosphate pathway for GA production were assessed. The most efficient L-arabinose metabolic pathway to GA was subsequently synergize with Dahms pathway to produce GA from D-xylose and L-arabinose. Overall, this study was the first to screen for appropriate L-arabinose pathway as well as the synergy of the L-arabinose pathway and Dahms pathway for GA production.
Synergistic Action Modes of Arabinan Degradation by Exo- and Endo- Arabinosyl Hydrolases
( Jung Mi Park ),( Myoung Uoon Jang ),( Gyo Won Oh ),( Eun Hee Lee ),( Jung Hyun Kang ),( Yeong-bok Song ),( Nam Soo Han ),( Tae Jip Kim ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.2
Two recombinant arabinosyl hydrolases, α-L-arabinofuranosidase from Geobacillus sp. KCTC 3012 (GAFase) and endo-(1,5)-α-L-arabinanase from Bacillus licheniformis DSM13 (BlABNase), were overexpressed in Escherichia coli, and their synergistic modes of action against sugar beet (branched) arabinan were investigated. Whereas GAFase hydrolyzed 35.9% of L-arabinose residues from sugar beet (branched) arabinan, endo-action of BlABNase released only 0.5% of L-arabinose owing to its extremely low accessibility towards branched arabinan. Interestingly, the simultaneous treatment of GAFase and BlABNase could liberate approximately 91.2% of L-arabinose from arabinan, which was significantly higher than any single exo-enzyme treatment (35.9%) or even stepwise exo- after endo-enzyme treatment (75.5%). Based on their unique modes of action, both exo- and endo-arabinosyl hydrolases can work in concert to catalyze the hydrolysis of arabinan to L-arabinose. At the early stage in arabinan degradation, exo-acting GAFase could remove the terminal arabinose branches to generate debranched arabinan, which could be successively hydrolyzed into arabinooligosaccharides via the endoaction of BlABNase. At the final stage, the simultaneous actions of exo- and endo-hydrolases could synergistically accelerate the L-arabinose production with high conversion yield.
전영주 ( Young Ju Jeon ),송성문 ( Sung Moon Song ),이창수 ( Chang Soo Lee ),김인호 ( In Ho Kim ) 한국화학공학회 2011 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.49 No.5
L-ribose has recently attracted interest as a starting material for antiviral drug. It could be obtained from L-arabinose by epimerization reaction. Epimerization reaction was carried out with molybdenium oxide or molybdic acid catalyst and methanol/water solution. Reaction temperature, methanol percentage, and catalyst kind were selected to find an optimum reaction condition. Ion exhange chromatography was used for separating epimerization reaction mixture, and then HPLC chromatogram of L-ribose fraction obtained to calculate the yield of the reaction. Shodex ion exchange HPLC column(Model SCl011) and Phenomenex Luna NH2 HPLC column were compared to employ a convenient HPLC analysis. It was found that the usage of 20% methanol, 60 ˚C, and 40 g/L molybdic acid gives the best reaction condition with a yield of 21%.
Metabolic Engineering for Improved Fermentation of L-Arabinose
( Suji Ye ),( Jeong-won Kim ),( Soo Rin Kim ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.3
L-Arabinose, a five carbon sugar, has not been considered as an important bioresource because most studies have focused on D-xylose, another type of five-carbon sugar that is prevalent as a monomeric structure of hemicellulose. In fact, L-arabinose is also an important monomer of hemicellulose, but its content is much more significant in pectin (3-22%, g/g pectin), which is considered an alternative biomass due to its low lignin content and mass production as juiceprocessing waste. This review presents native and engineered microorganisms that can ferment L-arabinose. Saccharomyces cerevisiae is highlighted as the most preferred engineering host for expressing a heterologous arabinose pathway for producing ethanol. Because metabolic engineering efforts have been limited so far, with this review as momentum, more attention to research is needed on the fermentation of L-arabinose as well as the utilization of pectin-rich biomass.
Min Li,Minhui Huang,Zhiguo Zhang,Qiwei Yang,Yiwen Yang,Zongbi Bao,Qilong Ren 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.10
L-arabinose and D-galactose could be released during the hydrolysis process of Arabic gum. The development of a crystallization process of L-arabinose is highly dependent on the knowledge of the solubility of both saccharides. In this work, the solubility of L-arabinose and D-galactose in binary mixtures of methanol-water or ethanolwater (mole fraction of water 0.5816) was determined at temperatures between 278.15 and 333.15K by a static equilibrium method. The experimental data correlated well with the modified Apelblat equation, the simplified polynomial empirical equation, NRTL model and UNIQUAC model. Additionally, the thermodynamic properties including the dissolution enthalpy and entropy were obtained from the experimental data. Within the studied temperature range, the dissolution is endothermic and the dissolution process is non-spontaneous.