• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.91-98
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• 2005

In order to investigate central metabolic changes in Beijerinckia indica, cells were grown on different carbon sources and intracellular flux distributions were studied under varying concentrations of nitrogen. Metabolic fluxes were estimated by combining material balances with extracellular substrate uptake rate, biomass formation rate, and exopolysaccharide (EPS) accumulation rate. Thirty-one metabolic reactions and 30 intracellular metabolites were considered for the flux analysis. The results revealed that most of the carbon source was directed into the Entner-Doudoroff pathway, followed by the recycling of triose-3-phosphate back to Hexose­6-phosphate. The pentose phosphate pathway was operated at a minimal level to supply the precursors for biomass formation. The different metabolic behaviors under varying nitrogen concentrations were observed with flux analysis.

• 원예과학기술지
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• 제34권6호
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• pp.898-911
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• 2016

Sugars play many important roles in plant metabolism and directly influence fruit quality. The effects of two edible coatings, 2% calcium chloride and 1% pullulan, on sugar metabolism in postharvest Huangguan pear fruit were investigated during cold storage. The respiration rate, sugar content and composition, sucrose metabolism enzyme activities [acid invertase (AIV), neutral invertase (NI), sucrose synthase (SS), and sucrose phosphate synthase (SPS)] and expression of the AIV gene were analyzed during storage at $0^{\circ}C$ for 210 days. Coating treatments slowed the decrease of sucrose and hexose, the respiration rate, and the activities of AIV, NI, SS and SPS, thus maintaining high total soluble solids (TSS) and titratable acid (TA) contents in the fruit. There were no significant differences in AIV expression or activity between the treated and control groups of fruits. Both of the coatings could inhibit the activities of sucrose-cleaving enzymes, thus slowing the decrease of sugar content and maintaining high fruit quality during cold storage.

• Applied Biological Chemistry
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• 제33권2호
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• pp.105-108
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• 1990

찹쌀현미의 호분층 수는 등부가 배부보다 많았고, 호분층 및 과피의 두께도 배부보다 등부 쪽이 두꺼웠으나 겨층구조는 품종마다 독특하였다. $60^{\circ}C$에서의 현미의 수분흡수속도는 다수계(한강찰벼와 백운찰벼)는 서로 비슷하였고 일반계(신선찰벼)보다 빨랐다. 고유점도는 한강찰벼가 1.92, 백운찰벼가 1.84, 신선찰벼가 1.73$dlg^{-1}$이었다. 시차주사열량기에 의한 전분의 호화온도는 백운찰벼가 가장 높았고, 한강찰벼가 가장 낮았다. 호화에 필요한 최소한의 수분함량은 한강찰벼가 38.0%, 백운찰벼가 36.3%, 신선찰벼가 37.8%이었다.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1711-1716
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• 2010

A gene encoding the ${\beta}$-xylosidase/${\alpha}$-arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium ${\beta}$-xylosidase/${\alpha}$-N-arabinosidase and Bacillus cellulosilyticus ${\alpha}$-arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a C-terminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on para-nitrophenyl-${\alpha}$-arabinofuranoside (pNPA) as well as para-nitrophenyl-${\beta}$-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

• 한국수소및신에너지학회논문집
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• 제25권1호
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• pp.11-18
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• 2014

This study was conducted to investigate the effect of thermal pre-treatment on bio-hydrogen from food waste. Two continuous reactors operated and VFAs(volatile fatty acids) production and microbial communities were analyzed. The average hydrogen yield was 0.50 and 0.33mol $H_2/mol$ $hexose_{added}$ in thermally treated food added reactor(R1) and control(R2), respectively. Butyrate concentration was similarly 7,500mg/L in both reactors, but two times higher lactate concentration was observed in R2(3,800mg/L). The results of FISH(fluorescence in situ hybridization) showed that the relative microorganism to hydrogen producing bacteria was 78 and 27% in R1 and R2, respectively.

• 약학회지
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• 제42권4호
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• pp.467-471
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• 1998

Numerous efforts have been made to isolate immunologically active component from Mori Cortex Radicis, since it has been used in the treatment of bronchial asthma, and immune dis order in human. Recently, we reported the purification of an anti-allergic component of the Mori Cortex Radicis. Among the fractions we prepared in the previous study, a fraction was active in the proliferation of murine lymphocytes. The active component (HHM 3-1) was elucidated as a polysaccharade with a small amount of lignin. When it was subjected to MALDI-MS by using 3-hydroxypicolinic acid as a matrix, the molecular weight of the component was estimated as 792688.2dalton. Total hexose and protein content of the component were estimated as 62.6% and 0.51%, respectively and it was composed mainly of glucose, galactose and mannose. The remaining part of the component was estimated as ligin because of the characteristic functional groups in IR and UV spectra. Concomitant treatment of HHM 3-1 with known mitogens synergistically increased the proliferation of B-cells and T-cells.

• 한국수소및신에너지학회논문집
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• 제26권5호
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• pp.409-415
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• 2015

This study was performed to optimize the integrated anaerobic digestion (AD) and microbial electrolysis cells (MECs) for the enhanced hydrogen production. The optimum operational conditions of integrated AD and MECs were obtained using response surface methodology. The optimum substrate concentration and operational pH were 10 g/L and 6.8, respectively. In the confirm test, 1.43 mol $H_2/mol$ hexose was achieved, which was 2.5 times higher than only AD. After 40 to 60 hour at seeding, the volatile fatty acids (VFAs) in reactor of AD were not changed. However the VFAs of reactor of AD-MECs were reduced by 61.3% (acetate: 76.4%, butyrate: 50.0%, lactate: 55.0%).

• 신재생에너지
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• 제18권2호
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• pp.9-17
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• 2022

In this study, we used the Flux Balance Analysis (FBA) program to examine the behavior of hydrogen and organic acids according to seasonal changes in food wastewater collected from D city. The results showed that average hydrogen conversion rates in spring, summer, autumn, and winter were 1.06, 0.71, 1.21, and 1.13 mol H₂/mol of hexose_added, respectively, indicating a significantly lower hydrogen conversion rate in summer than in other seasons. This phenomenon is believed to occur because the carbohydrate concentration of the incoming food wastewater is low. In addition, Lactobacillus, the lactic acid-producing bacterium, was 21.3% in spring, 27.2% in summer, 17.5% in autumn, and 22.6% in winter. The most distinctive feature of the microbial community in summer was that 15.3% of the Ilyobacter was analyzed. It was confirmed that Ilyobacter, which is involved in the production of acetic acid and propionic acid, is closely associated with the tendency of increasing acetic acid and propionic acid and thus contributes to organic acid change. Clostridium, a hydrogen-producing bacterium, was 76.2%, 50.8%, 78.3%, and 74%, in spring, summer, autumn, and winter, respectively. It was confirmed that Clostridium dominates the microbial community by approximately 70% or more in all seasons except summer.

• 동아시아식생활학회지
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• 제15권1호
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• pp.100-105
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• 2005

This study was conducted to investigate the extraction characteristics of the polysaccharide from Jeseng mushroom (Fomitopsis pinicola Jeseng). Yields of the polysaccharide extracted from powdered mushroom by autoclaving(120, 30 min) with water at different pH and salt concentration were 8.2～9.2% in pH 5～11, 4.7～5.5% in 1～5% salt solution, respectively. The yield by the 0.05～1.0 N KOH-extraction was ranged 3.45～13.20%, while that by HAS-extraction(homogenizing after KOH swelling) using 1～2.5 N KOH 73.6～78.4%. Content of carbohydrate, protein, lipid and ash of the crude polysaccharide extracted from fruits body and its cultured mycelium by method of water extraction, KOH extraction(0.005～1N) and HAS-extraction were ranged 86.5～92.6%, 2.3～13.1%, 0.1～4.2% and 0.1～1.7%, respectively. The polysaccharide were composed of 62.0～77.8 g/g of pentose, 138.0～187.8 g/g of hexose and 21.2～117.3 mg/g of protein. From these results, the polysaccharide extracted was supposed to be a protein-bound polysaccharide.

• KSBB Journal
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• 제25권4호
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• pp.351-356
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• 2010

리르노셀룰로오스로부터 생산된 글루코오스와 자일로 오스의 혼합당을 동시에 발효하여 에탄올 생산을 증가시키며, 또한 에탄올 생산에서의 세포고정화의 영향과 ICR (immobilized cell reactor)을 이용한 혼합당에서의 에탄올 연속생산을 수행하였다. 고정화 P. stipitis를 이용한 플라스크에서 에탄올을 생산에 대한 혼합당과 질소원의 영향으로부터 5% 혼합당 (글루코오스/자일로오스 = 3:1)과 1% 질소원이 최적으로 타나났으며, 이때 생산된 에탄올 농도는 약 19-20 g/L이었다. 고정화된 P. stipitis을 이용하여 반복적 유가식배양 (repeated fed-batch)으로 에탄올을 생산하였을 때는 모든 당 농도에서 글루코오스는 빠르게 소비되었지만, 혼합당의 농도가 높아질수록 자일로오스의 소비속도는 점차적으로 감소하였다. 즉 혼합당 농도가 증가하면서 더불어 당 소비속도는 감소하였다. 또한 ICR에서 1% 혼합당을 연속적으로 공급하면서 에탄올을 안정적으로 생산하여, 에탄올 농도는 5.6 g/L이었고 에탄올 생산 속도는 0.13 g/$L{\cdot}h$이었다.