Oxygen-dependent enhancement of hydrogen production by engineering bacterial hemoglobin in Escherichia coli

Jo, B.H.,Kim, J.Y.H.,Seo, J.H.,Cha, H.J. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.20

H<SUB>2</SUB> production under aerobic conditions has been proposed as an alternative method to overcome the fundamentally low yield of H<SUB>2</SUB> production by fermentative bacteria by maximizing the number of electrons that are available for H<SUB>2</SUB>. Here, we engineered Vitreoscilla hemoglobin (VHb) in Escherichia coli to study the effects of this versatile oxygen (O<SUB>2</SUB>)-binding protein on oxic H<SUB>2</SUB> production in a closed batch system that was supplemented with glucose. The H<SUB>2</SUB> yields that were obtained with the VHb-expressing E. coli were greatly enhanced in comparison to the negative control cells in culture that started with high O<SUB>2</SUB> tensions. The formate hydrogen lyase (FHL) activity of oxically cultured, VHb-expressing cells was also much higher than that of the negative control cells. Through inhibitor studies and time-course experiments, VHb was shown to contribute to the improved H<SUB>2</SUB> yield primarily by increasing the efficiency of cellular metabolism during the aerobic phase before the onset of H<SUB>2</SUB> production and not by working as an O<SUB>2</SUB>-scavenger during H<SUB>2</SUB> production. This new approach allowed more substrate to remain to be further utilized for the production of more H<SUB>2</SUB> from limited resources. We expect that VHb can be successfully engineered in potential aerobic H<SUB>2</SUB>-producing microbial systems to enhance the overall H<SUB>2</SUB> production yield. In addition, the remarkably high FHL activity of oxically grown, VHb-expressing cells may make this engineered strain an attractive whole-cell biocatalyst for converting formate to H<SUB>2</SUB>.

돼지 H-FABP 유전자의 다형성 및 경제 형질과의 연관성 구명

최봉환,김태헌,이지웅,조용민,이혜영,조병욱,정일정 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.5

The purpose of this study was to detect association between genetic variation and economic trait in the porcine heart type fatty acid-binding protein gene as a candidate gene for the traits related with growth and meat quality in pigs. The H-FABP is a 15-kDa protein expressed in several tissues with high demand for fat metabolism such as cardiac and skeletal muscle and lactating mammary gland. H-FABP is small intracellular protein involved in fatty acid transport from the plasma membrane to the site of β-oxidation and/or triacylglycerol or phospholipid synthesis. In this study, H-FABP PCR-RFLP was performed in F_(2) population composed of 214 individuals form an intercross between Korean Native Boars and Landrace sows. PCR products form tow primer sets within H-FABP gene were amplified in 850bp and 700bp. Digestion of PCR products with the restriction digestion enzymes HaeⅢ and Hinf Ⅰ, revealed fragment length polymorphisms(RFL. Ps). The genotype frequencies from H-FABP/HaeⅢ was .29 for genotype DD, .53 for genotype Dd, and .15 for genotype dd, respectively. The genotype frequencies of HH, Hh, and hh from H-FABP(hinf Ⅰ was .38, .41, and .20, respectively, in the population.Relationships between their genotypes and economic traits were estimated. In H-FABP/HaeⅢ locus, there were specific genotypes(Dd and dd) associated with economic traits such as body weight. In H-FABP/Hinf Ⅰ Iocus, Genotypes of HH and Hh associated with growth traits such as body weights at 5, 12, and 30 week of age (p<.05 or p<.001) and back fat thickness, body fat including abdominal and trimmed fat (p<.001) and intramuscular fat(p<.05). The 'H'allele was positivecly associated with gaining of body weight and fatness deposition. In conclusion, a significant association of the H-FABP gene from its genetic variation was found on body weight, intramuscular fat and backfat thickness.

On the zeolitic imidazolate framework-8 (ZIF-8) membrane for hydrogen separation from simulated biomass-derived syngas

Yin, H.,Lee, T.,Choi, J.,Yip, A.C.K. Elsevier 2016 Microporous and mesoporous materials Vol.233 No.-

<P>Hydrogen separation from biomass-derived syngas is a critical step in the utilization of gasification technology. Compared with the traditional methods, membrane technology provides an effective and low-cost solution for adjusting the gas composition and collecting H-2 in syngas environments. In this study, a zeolitic imidazolate framework-8 (ZIF-8)-based membrane, which is a potential candidate for H-2 separation from biomass-derived syngas, was successfully fabricated through the seeded (secondary) growth method and the subsequent post-treatments. The prepared ZIF-8 membrane exhibited a modest H-2 separation performance for H-2/CO2 and H-2/CO, with separation factors of 4.95 and 6.08, respectively, and a H-2 permeance of 7.81 x 10(-8) mol m(-2) s(-1) Pa-1 at 200 degrees C in the simulated biomass-derived syngas environments (H-2/CO2/CO) with the presence of steam. In particular, the H-2/CO2 and H-2/CO separation factors were increased by 36% and 97%, respectively, with respect to those obtained through bare supports. Despite the promising H2 perm-selectivity, the H-2/CO2 and H-2/CO separation factors of ZIF-8 membranes at 200 degrees C under water-containing syngas environments were maintained up to 10 h but the longer exposure led to the gradual degradation and eventual reduction toward those of bare supports after 15 h seemingly due to the water-involved membrane degradation. This study provides the availability and limitation of ZIF-8 membranes for H-2 separations in stimulated biomass-derived syngas environments. (C) 2015 Elsevier Inc. All rights reserved.</P>

A multi-virus detectable microfluidic electrochemical immunosensor for simultaneous detection of H1N1, H5N1, and H7N9 virus using ZnO nanorods for sensitivity enhancement

Han, J.H.,Lee, D.,Chew, C.H.C.,Kim, T.,Pak, J.J. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.228 No.-

This paper describes a multi-detectable and nano-flow immunosensor based on ZnO nanorods (NRs) grown on the inner surface of PDMS sensor region for sensing H1N1, H5N1, and H7N9 influenza viruses simultaneously using electrochemical method. Nanostructured ZnO NRs with a high isoelectric point (IEP ~9.5) tend to interact electrostatically with proteins with lower IEP such as H1N1, H5N1, and H7N9 antibodies. ZnO NRs were hydrothermally grown on the upper inner surface of the nano-flow PDMS sensor region. The forementioned three influenza viruses were successfully detected from three separate sensing regions by measuring the oxidation current of 3,3',5,5'-tetramethylbenzidine (TMB) by horseradish peroxidase (HRP) conjugated on capture antibody of those influenza viruses when proper potential was applied. The proposed immunosensors were evaluated using 1pg/ml, 10pg/ml, 100pg/ml, 1ng/ml, and 10ng/ml of H1N1, H5N1, and H7N9 antigens by amperometry. These immunosensors showed high selectivity toward H1N1, H5N1, and H7N9, which was successfully confirmed by distinguishing the target virus individually from a mixture of three virus antigens. A low limit of detection was demonstrated by detecting as low as 1pg/ml of each virus and it is believed that this was possible by enhancing the sensitivity with the ZnO NRs grown on the PDMS surface in the sensing region. The steady-state oxidation current output linearly increased with respect to the logarithm of the H1N1, H5N1, and H7N9 virus concentrations in the range of 1-10ng/ml.

Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos)

H.C. Liu,J.F. Huang,S.R. Lee,H.L. Liu,C.H. Hsieh,C.W. Huang,M.C. Huang,C. Tai,J.P. Poivey,R. Rouvier,Y.S. Cheng 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie (h2 = 0.07±0.03) and M (h2 = 0.07±0.01), moderately low for Dm (h2 = 0.13±0.02), of medium values for H (h2 = 0.20±0.03) and F (h2 = 0.23±0.03). High and favourable genetic correlations existed between F and Dm (rg = 0.93), between F and H (rg = 0.97) and between Dm and H (rg = 0.90). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings’ feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

Advanced H2O2 oxidation for diethyl phthalate degradation in treated effluents: effect of nitrate on oxidation and a pilot-scale AOP operation

Ko, K. B.,Park, C. G.,Moon, T. H.,Ahn, Y. H.,Lee, J. K.,Ahn, K. H.,Park, J. H.,Yeom, I. T. IWA Publishing 2008 Water Science & Technology Vol.58 No.5

<P>One of the objectives of this study was to delineate the effect of nitrate on diethyl phthalate (DEP) oxidation by conducting a bench-scale ultraviolet (UV)/H2O2 and O3/H2O2 operations as suggested in a previous study. We also aim to investigate DEP oxidation at various UV doses and H2O2 concentrations by performing a pilot-scale advanced oxidation processes (AOP) system, into which a portion of the effluent from a pilot-scale membrane bioreactor (MBR) plant was pumped. In the bench-scale AOP operation, the O3 oxidation alone as well as the UV irradiation without H2O2 addition could be among the desirable alternatives for the efficient removal of DEP dissolved in aqueous solutions at a low DEP concentration range of 85±15 μg/L. The adverse effect in the UV/H2O2 process was significantly greater than that in the UV oxidation alone, and its oxidation was almost halved by the nitrate. However, the nitrate clearly enhanced the DEP oxidation in the O3 oxidation and O3/H2O2 process. Especially, the addition of nitrate almost doubled the DEP oxidation efficiency in the O3/H2O2 process. The series of pilot-scale AOP operations confirmed that about 30-50% of DEP dissolved in the treated MBR effluent streams was, at least, oxidized by the O3 oxidation alone as well as the UV irradiation without H2O2 addition. The UV photolysis of H2O2 was most effective for DEP degradation with an H2O2 concentration of 40 mg/L at a UV dose of 500 mJ/cm2.</P>

Synthesis, crystal structures, and deprotonation of cis- and trans-octahedral nickel(II) complexes with a 14-membered tetraaza macrocycle bearing two N-phenacyl pendant arms

Kim, H.,Kang, S.G.,Kwak, C.H. Elsevier Sequoia [etc.] 2012 Inorganica chimica acta Vol.387 No.-

The di-N-functionalized macrocycle 2,13-bis(2-phenacyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.<SUP>1.18</SUP>0<SUP>7.12</SUP>]docosane (H<SUB>2</SUB>L<SUP>2</SUP>) bearing two N-CH<SUB>2</SUB>COC<SUB>6</SUB>H<SUB>5</SUB> groups has been prepared by the reaction of 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.0<SUP>7.12</SUP>]docosane (L<SUP>1</SUP>) with phenacyl bromide. Interestingly, H<SUB>2</SUB>L<SUP>2</SUP> reacts with Ni<SUP>2+</SUP> ion to form two geometric isomers, trans-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)]<SUP>2+</SUP> and cis-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)]<SUP>2+</SUP>. The axial Ni-O (N-CH<SUB>2</SUB>COC<SUB>6</SUB>H<SUB>5</SUB> group) bond distance (2.080(2)A) of trans-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)](ClO<SUB>4</SUB>)<SUB>2</SUB>.2DMSO is shorter than the in-plane Ni-N distances (2.096(2) and 2.100(2)A). However, the Ni-O distances (2.105(2) and 2.124(2)A) of cis-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)](ClO<SUB>4</SUB>)<SUB>2</SUB>.H<SUB>2</SUB>O are considerably longer than the Ni-N distances (2.053(2)-2.086(2)A). Each N-CH<SUB>2</SUB>COC<SUB>6</SUB>H<SUB>5</SUB> group of trans-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)]<SUP>2+</SUP> and cis-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)]<SUP>2+</SUP> exists as its keto form in the solid state and in various solvents. Two N-CH<SUB>2</SUB>COC<SUB>6</SUB>H<SUB>5</SUB> groups of trans-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)]<SUP>2+</SUP> are readily deprotonated in basic aqueous solutions, producing the enolate form trans-[Ni(L<SUP>2</SUP>)]. On the other hand, cis-[Ni(H<SUB>2</SUB>L<SUP>2</SUP>)]<SUP>2+</SUP> undergoes deprotonation to yield cis-[Ni(HL<SUP>2</SUP>)]<SUP>+</SUP>, in which one N-CH<SUB>2</SUB>COC<SUB>6</SUB>H<SUB>5</SUB> group is not deprotonated, under similar conditions.

The H <small>i</small> environment of counter‐rotating gas hosts: gas accretion from cold gas blobs

Chung, Aeree,Bureau, Martin,van Gorkom, J. H.,Koribalski, Bä,rbel Blackwell Publishing Ltd 2012 Monthly notices of the Royal Astronomical Society Vol.422 No.2

<P><B>ABSTRACT</B></P><P>We probe the H <SMALL>i</SMALL> properties and the gas environments of three early‐type barred galaxies harbouring counter‐rotating ionized gas: NGC 128, NGC 3203 and NGC 7332. Each system has one or more optically identified galaxy at a similar or as yet unknown redshift within a 50‐kpc projected radius. Using H <SMALL>i</SMALL> synthesis imaging data, we investigate the hypothesis that the counter‐rotating gas in these galaxies has been accreted from their neighbours. In NGC 128 and NGC 3203, we find 9.6 × 10<SUP>7</SUP> and 2.3 × 10<SUP>8</SUP> M<SUB>⊙</SUB> of H <SMALL>i</SMALL>, respectively, covering almost the entire stellar bodies of dwarf companions that appear physically connected. Both the H <SMALL>i</SMALL> morphology and kinematics are suggestive of tidal interactions. In NGC 7332, we do not find any directly associated H <SMALL>i</SMALL>. Instead, NGC 7339, a neighbour of a comparable size at about 10 kpc, is found with 8.9 × 10<SUP>8</SUP> M<SUB>⊙</SUB> of H <SMALL>i</SMALL> gas. More recently in a single dish observation, however, another group discovered a large H <SMALL>i</SMALL> structure which seems to be an extension of NGC 7339’s H <SMALL>i</SMALL> disc and also covers NGC 7332. All these observations thus suggest that H <SMALL>i</SMALL> gas is being accreted in these three galaxies from their companions, which is likely responsible for the kinematically decoupled gas component present in their central region. In particular, the dynamical friction time‐scales of the nearest neighbours with H <SMALL>i</SMALL> gas of NGC 128 and NGC 3203 are comparable to their orbital time‐scales around the counter‐rotators, several ∼10<SUP>8</SUP> yr, implying that those neighbours will likely soon merge with the primary galaxies, fuelling them with gas. NGC 7332 also appears to be in the merging process with its neighbour through the common H <SMALL>i</SMALL> envelope. Besides, we find some other potential gas donors around NGC 128 and NGC 7332: two H <SMALL>i</SMALL>‐rich galaxies with <IMG src='/wiley-blackwell_img/equation/MNR_20679_mu1.gif' alt ='inline image'/> and 2.5 × 10<SUP>9</SUP> M<SUB>⊙</SUB> at a distance of ≈67 kpc from NGC 128 and two dwarf systems with <I>M</I><SUB>HI</SUB>= 3.9 × 10<SUP>7</SUP> and 7.4 × 10<SUP>7</SUP> M<SUB>⊙</SUB> at ≲100 kpc from NGC 7332. Among the seven H <SMALL>i</SMALL> features identified in this study, three of them are associated with dwarf galaxies, two of which have only been recently identified in a blind survey, while the third one is still not catalogued at optical wavelengths. Considering the incompleteness of existing studies of the faint dwarf galaxy population both in the optical and in H <SMALL>i</SMALL>, accretion from cold gas blobs, presumably gas‐rich dwarfs, is expected to occur even more frequently than what is inferred from such cases that have been observed to date.</P>

Enhanced H₂ fermentation of organic waste by CO₂ sparging

Kim, D.H.,Shin, H.S.,Kim, S.H. Pergamon Press ; Elsevier Science Ltd 2012 International journal of hydrogen energy Vol.37 No.20

This study aimed to improve the productivity of dark fermentative hydrogen production from organic waste. An anaerobic sequencing batch reactor was used for hydrogen fermentation and it was fed with food waste (VS 4.4 +/- 0.2% containing 27 g carbohydrate-COD/L) at various CO<SUB>2</SUB> sparging rates (40-120 L/L/d), hydraulic retention times (HRTs; 18-42 h), and solid retention times (SRTs; 18-160 h). CO<SUB>2</SUB> sparging increased the H<SUB>2</SUB> productivity by 5-36% at all the examined conditions, confirming the benefit of the replacement of headspace gas by CO<SUB>2</SUB>. The maximum H<SUB>2</SUB> production was obtained by CO<SUB>2</SUB> sparging at 80 L/L/d, resulting in the H<SUB>2</SUB> productivity of 3.18 L H<SUB>2</SUB>/L/d and the H<SUB>2</SUB> yield of 97.3 mL H<SUB>2</SUB>/g VS<SUB>added</SUB>. Increase of n-butyrate and isopropanol yields were concurrent with the enhanced H<SUB>2</SUB> yield by CO<SUB>2</SUB> sparging. Acidogenic efficiency, the sum of H<SUB>2</SUB>, organic acid, and alcohol, in the CO<SUB>2</SUB>-sparged reactor ranged from 47.9 to 56.0%, which was comparable to conventional acidogenesis. Thermodynamic analysis confirmed that both CO<SUB>2</SUB> sparging and CO<SUB>2</SUB> removal were beneficial for H<SUB>2</SUB>-producing reactions, but CO<SUB>2</SUB> sparing has more profound effect than CO<SUB>2</SUB> removal on inhibiting H<SUB>2</SUB>-consuming reactions.

Accelerated cosmological expansion without tension in the Hubble parameter : Fast evolution of the Hubble parameter <i>H(z)</i>

van Putten, Maurice H.P.M.,Gwak, B.,Kang, G.,Kim, C.,Kim, H.-C.,Lee, C.-H.,Lee, J.,Lee, S.,Lee, W. EDP Sciences 2018 The European Physical Journal Conferences Vol.168 No.-

<P>The <I>H</I>0-tension problem poses a confrontation of dark energy driving latetime cosmological expansion measured by the Hubble parameter<I> H</I>(<I>z</I>) over an extended range of redshifts <I>z</I>. Distinct values <I>H</I>0 ≃ 73 km s<SUP>-1</SUP> Mpcs<SUP>-1</SUP> and <I>H</I>0 ≃ 68 km s<SUP>-1</SUP> Mpcs<SUP>-1</SUP> obtain from surveys of the Local Universe and, respectively, ΛCBM analysis of the CMB. These are representative of accelerated expansion with <I>H</I>′(0) ≃ 0 by [see formula in PDF] and, respectively, <I>H</I>′(0) > 0 in ΛCDM, where [see formula in PDF] is a fundamental frequency of the cosmological horizon in a Friedmann-Robertson-Walker universe with deceleration parameter <I>q</I>(<I>z</I>) = -1 + (1+z)<I>H</I><SUP>-1</SUP><I>H</I>′(z). Explicit solution <I>H</I>(z) = <I>H</I>0 [see formula in PDF] and, respectively, <I>H</I>(z) = <I>H</I>0[see formula in PDF] are here compared with recent data on <I>H</I>(<I>z</I>) over 0 ≲ z ≲ 2.The first is found to be free of tension with H0 from local surveys, while the latter is disfavored at 2:7σ A further confrontation obtains in galaxy dynamics by a finite sensitivity of inertia to background cosmology in weak gravity, putting an upper bound of <I>m</I> ≲ 10<SUP>-30</SUP> eV on the mass of dark matter. A <I>C</I><SUP>0</SUP> onset to weak gravity at the de Sitter scale of acceleration <I>adS</I> = <I>cH</I>(<I>z</I>), where <I>c</I> denotes the velocity of light, can be seen in galaxy rotation curves covering 0 ≲ <I>z</I> ≲ 2 Weak gravity in galaxy dynamics hereby provides a proxy for cosmological evolution.</P>