http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Song, Yoseb,Lee, Jin Soo,Shin, Jongoh,Lee, Gyu Min,Jin, Sangrak,Kang, Seulgi,Lee, Jung-Kul,Kim, Dong Rip,Lee, Eun Yeol,Kim, Sun Chang,Cho, Suhyung,Kim, Donghyuk,Cho, Byung-Kwan National Academy of Sciences 2020 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.117 No.13
<P><B>Significance</B></P><P>Despite sharing the first four reactions, coutilization of the Wood–Ljungdahl pathway (WLP) with the glycine synthase-reductase pathway (GSRP) and reductive glycine pathway (RGP) to fix C1 compounds has remained unknown. In this study, using <I>Clostridium drakei</I>, we elucidated the role of the GSRP and RGP in the presence of the WLP, via a genome-scale metabolic model, RNA-seq, <SUP>13</SUP>C isotope-based metabolite-tracing experiments, biochemical assays, and heterologous expression. Overall, the data suggested the pathways are functional under autotrophic conditions. Along with the WLP, GSRP and RGP convert CO<SUB>2</SUB> to glycine and then to acetyl-phosphate and serine, which then obtain ATP by producing acetate and operate with limited reducing power. This is a unique coutilization of the pathways under autotrophic conditions in acetogens.</P><P>Among CO<SUB>2</SUB>-fixing metabolic pathways in nature, the linear Wood–Ljungdahl pathway (WLP) in phylogenetically diverse acetate-forming acetogens comprises the most energetically efficient pathway, requires the least number of reactions, and converts CO<SUB>2</SUB> to formate and then into acetyl-CoA. Despite two genes encoding glycine synthase being well-conserved in WLP gene clusters, the functional role of glycine synthase under autotrophic growth conditions has remained uncertain. Here, using the reconstructed genome-scale metabolic model <I>i</I>SL771 based on the completed genome sequence, transcriptomics, <SUP>13</SUP>C isotope-based metabolite-tracing experiments, biochemical assays, and heterologous expression of the pathway in another acetogen, we discovered that the WLP and the glycine synthase pathway are functionally interconnected to fix CO<SUB>2</SUB>, subsequently converting CO<SUB>2</SUB> into acetyl-CoA, acetyl-phosphate, and serine. Moreover, the functional cooperation of the pathways enhances CO<SUB>2</SUB> consumption and cellular growth rates via bypassing reducing power required reactions for cellular metabolism during autotrophic growth of acetogens.</P>
Determination of single nucleotide variants in Escherichia coli DH5α by using short-read sequencing
Song, Yoseb,Lee, Bo-Rahm,Cho, Suhyung,Cho, Yoo-Bok,Kim, Seon-Won,Kang, Taek Jin,Kim, Sun Chang,Cho, Byung-Kwan Published by Elsevier/North Holland on behalf of t 2015 FEMS microbiology letters Vol.362 No.11
Fabrication and characterization of thermochemical hydrogen sensor with laminated structure
Kim, Seil,Song, Yoseb,Lim, Hyo-Ryoung,Kwon, Young-Tae,Hwang, Tae-Yeon,Song, Eunpil,Lee, Songjun,Lee, Young-In,Cho, Hong-Baek,Choa, Yong-Ho Elsevier 2017 International journal of hydrogen energy Vol.42 No.1
<P><B>Abstract</B></P> <P>In this study, we reported the simple and cost-effective fabrication of thermochemical hydrogen (TCH) sensors composed of chalcogenide thin films and Pt/Al<SUB>2</SUB>O<SUB>3</SUB> powders. Chalcogenide thin films of two types, composed of Bi<SUB>2</SUB>Te<SUB>3</SUB> (monomorphic-type) and Bi<SUB>2</SUB>Te<SUB>3</SUB> Sb<SUB>2</SUB>Te<SUB>3</SUB> (four-leg PN junction-type), were prepared by electrochemical deposition. The Pt/Al<SUB>2</SUB>O<SUB>3</SUB> powder, which acts as a heating catalyst, was synthesized by impregnation of an Al<SUB>2</SUB>O<SUB>3</SUB> powder with an aqueous solution of platinum (IV) chloride pentahydrate. Its heating process was optimized via a hydrogen-sensing evaluation to control the size of the Pt particles. The monomorphic-type TCH sensor showed an output signal of 14.2 μV in response to 10 vol% hydrogen gas, whereas an output signal of 39.6 μV was obtained from a four-leg PN junction–type TCH sensor. Even though the n–p junction-type had the same deposition area as that of the monomorphic-type, the output signal of the n–p junction TCH sensor was greater by a factor of 2.8. In addition, the monomorphic-type TCH sensor had an inferior response time (T<SUB>90</SUB>) of 31 s and a longer recovery time (D<SUB>10</SUB>) of 38 s; the four-leg PN junction-type TCH sensor had a lowest response time of 27 s and a fastest recovery time of 9 s (in 3% H<SUB>2</SUB>/air at room temperature).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Thermochemical hydrogen sensor composed of chalcogenide thin film and Pt/Al<SUB>2</SUB>O<SUB>3</SUB> catalyst was fabricated. </LI> <LI> Voltage signal of the n–p junction type sensor was higher than monomorphic type sensor. </LI> <LI> Heat dissipation of n–p junction type sensor was superior to that of monomorphic type one. </LI> <LI> Response and recovery time of n–p junction type sensor were 27.4 and 9.6 s in 3% H<SUB>2</SUB>/air. </LI> </UL> </P>
Jiyun BAE,Yoseb SONG,Byung-Kwan CHO 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10
Eubacterium limosum is one of important acetogenic bacteria for utilizing C1 feedstocks, such as CO₂, CO, and methanol. Despite previous molecular level studies, systematic understanding of its metabolism has been limited. To unravel a complex metabolic network, a genome-scale metabolic model of E. limosum was reconstructed. Using its genetic information and BiGG, KEGG, and Metacyc databases, the model resulted in having 652 genes, 937 reactions, and 855 metabolites. To improve the accuracy of the model, yeast extract supplementation required to grow E. limosum had to be avoided for accurate representation of chemical compositions of the growth media. Adaptive laboratory evolution of E. limosum was implemented under H₂-CO₂ condition in defined media without yeast extract. After updating the model and recalculating objective functions from the evolved strain, growth rate and production rate were accurately predicted and in accord with experimental data. The model and in silico simulation analysis will allow systematic understanding of acetogenic metabolisms and a rational approach to engineer strains that efficiently convert C1 substrates into multi-carbon products.
Kim, Seil,Song, Yoseb,Ryu, Seung Han,Hwang, Tae-Yeon,Lee, Youngsuk,Lim, Jae-Hong,Lee, Joo-Yul,Lee, Kyu-Hwan,Choa, Yong-Ho Elsevier Sequoia 2019 Synthetic metals Vol.254 No.-
<P><B>Abstract</B></P> <P>A three-dimensional thermoelectric (TE) nanocomposite based on functionalized single-walled carbon nanotubes (f-SWCNTs), tellurium nanowires (Te NWs), and polymethyl methacrylate (PMMA) microbeads was fabricated by a hot compaction via solvent casting. We chose a minimum content of f-SWCNTs of 1 wt% for fabricating the nanocomposite based on percolation threshold. The nanocomposite containing 2 wt% f-SWCNTs and 48 wt% Te NWs exhibited an electrical conductivity of 0.93 S/cm, a Seebeck coefficient of 303 μV/K, a thermal conductivity of 0.23 W/mK and a figure-of-merit (<I>ZT</I>) of 0.01 at RT. The electrical conductivity of the nanocomposite were higher than that of the Te NW/PMMA nanocomposite. In contrast, the thermal conductivity value showed a trend opposite to that of the electrical conductivity. This is because the f-SWCNTs formed bridges between the Te NWs into the nanocomposite, resulting in heterostructured interfaces. We believe that this-type nanocomposite can be widely used for thermoelectric generators at low temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A hybrid TE nanocomposite was fabricated by hot compaction via solvent casting. </LI> <LI> Functionalized-SWCNTs formed bridges between the Te NWs in the TE nanocomposite. </LI> <LI> The thermal conductivity is insensitive to f-SWCNT density due to poor thermal transfer between Te NW and f-SWCNTs. </LI> <LI> The hybrid nanocomposite exhibited a figure-of-merit (<I>ZT</I>) of 0.01 at room temperature. </LI> </UL> </P>