The Effect of Incremental Acidification on the Solubility of Phosphorus in Alkaline Vertisols

Karl Andersson,Matt Tighe,Chris Guppy,Paul Milham,Tim Mclaren 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

The Effect of Light on Champagne Yeast Cell Growth and Ethanol Production Under Variable pH Conditions

Paul C. Collins,Karl B. Schnelle,Jr. George W. Malaney,Robert D. Tanner 한국생물공학회 1991 KSBB Journal Vol.6 No.2

The Effect of Light on Champagne Yeast Cell Growth and Ethanol Production Under Variable pH Conditions

Collins, Paul C.,Schnelle, Karl B.,Malaney, Jr.George W.,Tanner, Robert D. The Korean Society for Biotechnology and Bioengine 1991 KSBB Journal Vol.6 No.2

The effect of wtlitc light on unaeraten growth of Baker's yeast and the accompanying ethanol production has been studied in a batch process at 27$^{\circ}C$. Over the 80-hour period of the Champagne yeast process without pH control, the cull growth was inhibited by the fluorescent light. Another observed difference between the runs is that the drop and subsequent rise in redox potential occurred much sooner in the fermentation with light than in the fermentation without light. This preliminary study indicated that ethanol production could be enhanced by light as the cell concentration is repressed. The possible pathway, shift of the sugar substrate toward ethanol and away from cells was manifested by another difference as well. As observed under the microscope, many of the yeast cells grown under light budded without dividing by the normal fission process as they did in the dark. Furthermore, the undivided and branched (light grown) cell did not agglutinate at the end of the fermentation process as did the distinct spherical (dark grown) cells.

Change in the Site of Electron-Transfer Reduction of a Zinc–Quinoxalinoporphyrin/Gold–Quinoxalinoporphyrin Dyad by Binding of Scandium Ions and the Resulting Remarkable Elongation of the Charge-Shifted-State Lifetime

Ohkubo, Kei,Garcia, Rachel,Sintic, Paul J.,Khoury, Tony,Crossley, Maxwell J.,Kadish, Karl M.,Fukuzumi, Shunichi WILEY-VCH Verlag 2009 Chemistry Vol.15 No.40

<P>The site of electron-transfer reduction of AuPQ<SUP>+</SUP> (PQ=5,10,15,20-tetrakis(3,5-di-tert-butylphenyl)quino-xalino[2, 3−b′]porphyrin) and AuQPQ<SUP>+</SUP> (QPQ=5,10,15,20-tetrakis(3,5-di-tert-butylphenyl)bisquinoxalino[2,3-b′:12,13-b′′]porphyrin) is changed from the Au<SUP>III</SUP> center to the quinoxaline part of the PQ macrocycle in the presence of Sc<SUP>3+</SUP> in benzonitrile because of strong binding of Sc<SUP>3+</SUP> to the two nitrogen atoms of the quinoxaline moiety. Strong binding of Sc<SUP>3+</SUP> to the corresponding nitrogen atoms on the quinoxaline unit of ZnPQ also occurs for the neutral form. The effects of Sc<SUP>3+</SUP> on the photodynamics of an electron donor–acceptor compound containing a linked Zn<SUP>II</SUP> and Au<SUP>III</SUP> porphyrin ([ZnPQ–AuPQ]PF<SUB>6</SUB>) have been examined by femto- and nanosecond laser flash photolysis measurements. The observed transient absorption bands at 630 and 670 nm after laser pulse irradiation in the absence of Sc<SUP>3+</SUP> in benzonitrile are assigned to the charge-shifted (CS) state (ZnPQ<SUP>.</SUP><SUP>+</SUP>–AuPQ). The CS state decays through back electron transfer (BET) to the ground state rather than to the triplet excited state. The BET rate was determined from the disappearance of the absorption band due to the CS state. The decay of the CS state obeys first-order kinetics. The CS lifetime was determined to be 250 ps in benzonitrile. Addition of Sc<SUP>3+</SUP> to a solution of ZnPQ–AuPQ<SUP>+</SUP> in benzonitrile caused a drastic lengthening of the CS lifetime that was determined to be 430 ns, a value 1700 times longer than the 250 ps lifetime measured in the absence of Sc<SUP>3+</SUP>. Such remarkable prolongation of the CS lifetime in the presence of Sc<SUP>3+</SUP> results from a change in the site of electron transfer from the Au<SUP>III</SUP> center to the quinoxaline part of the PQ macrocycle when Sc<SUP>3+</SUP> binds to the quinoxaline moiety, which decelerate BET due to a large reorganization energy of electron transfer. The change in the site of electron transfer was confirmed by ESR measurements, redox potentials, and UV/Vis spectra of the singly reduced products.</P> <B>Graphic Abstract</B> <P>Long lifetime! A dramatic effect of Sc<SUP>3+</SUP> was observed on the electron-transfer reduction of gold(III) quinoxalino- and bisquinoxalinoporphyrins (AuPQ<SUP>+</SUP> and AuQPQ<SUP>+</SUP>) (see figure), which not only changes the site of electron transfer from the Au<SUP>III</SUP> metal to the fused quinoxaline part of the PQ macrocycle, but also leads to a remarkable elongation of the lifetime of the charge-shifted state of a ZnPQ–AuPQ dyad in benzonitrile. This is due to the strong binding of Sc<SUP>3+</SUP> to the ZnPQ and AuPQ<SUP>+</SUP> moieties. <img src='wiley_img/09476539-2009-15-40-CHEM200901105-content.gif' alt='wiley_img/09476539-2009-15-40-CHEM200901105-content'> </P>

Comparative analysis of ammonia monooxygenase (amoA) genes in the water column and sediment–water interface of two lakes and the Baltic Sea : amoA in lakes and the Baltic Sea

Kim, Ok-Sun,Junier, Pilar,Imhoff, Johannes F.,Witzel, Karl-Paul Oxford University Press 2008 FEMS microbiology ecology Vol.66 No.2

FOLLOW-UP OBSERVATIONS TOWARD PLANCK COLD CLUMPS WITH GROUND-BASED RADIO TELESCOPES

LIU, TIE,WU, YUEFANG,MARDONES, DIEGO,KIM, KEE-TAE,MENTEN, KARL M.,TATEMATSU, KEN,CUNNINGHAM, MARIA,JUVELA, MIKA,ZHANG, QIZHOU,GOLDSMITH, PAUL F,LIU, SHENG-YUAN,ZHANG, HUA-WEI,MENG, FANYI,LI, DI,LO, NA The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature (< 14 K) of Planck cold clumps makes them promising candidates for prestellar objects or for sources at the very initial stages of protostellar collapse. We have been conducting a series of observations toward Planck cold clumps (PCCs) with ground-based radio telescopes. In general, when compared with other star forming samples (e.g. infrared dark clouds), PCCs are more quiescent, suggesting that most of them may be in the earliest phase of star formation. However, some PCCs are associated with protostars and molecular outflows, indicating that not all PCCs are in a prestellar phase. We have identified hundreds of starless dense clumps from a mapping survey with the Purple Mountain Observatory (PMO) 13.7-m telescope. Follow-up observations suggest that these dense clumps are ideal targets to search for prestellar objects.

한국 시화호와 중국 Aha호 저질토에 분포하는 이화성 아황산염 환원효소 유전자의 비교 분석

김인선,김옥선,전선옥,안태석,Kim, In-Seon,Kim, Ok-Sun,Jeon, Sun-Ok,Witzel, Karl-Paul,Ahn, Tae-Seok 한국미생물학회 2008 미생물학회지 Vol.44 No.2

한국의 시화호와 중국의 Aha호 저질토에서 서식하는 황산염 환원세균(sulfate reducing bacteria, SRB)의 깊이에 따른 군집구조를 비교하기 위하여, 이화성 아황산염 환원효소(EC 1.8.99.1; dissimilatory sulfite reductase, dsr) 유전자를 대상으로, polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE) 및 클론 라이브러리를 이용하여 미생물의 군집구조를 분석하였다. DGGE band 양상을 분석한 결과, Aha호 보다는 시화호에서 더 맡은 밴드를 보여 다양성이 높았고, 깊이별 차이는 나타나지 않았다. 두 서식지에서 얻은총68개 클론의 염기서열을 가지고 계통학적 분석을 한 결과 시화호에서는 Deltaproteobacteria 그룹, Firmicutes 그룹에 속해있는 Desulfotomaculum 종과 archaeal thermophilic SRB 그룹에 속해있는 Archaeoglobus 종이, Aha호에서는 Desulfotomaculum 그룹과 유사성이 높았다. 분리된 대부분의 클론들(59%)은 배양된 황산염 환원세균과는 매우 낮은 유사도를 보였고, 환경에서 분리된 클론들과도90% 이하의 유사도를 나타냈다. 총 클론을 88% 유사도를 기준으로 9그룹으로 나뉘었을 때 시하호와 Aha호의 각 클론은 서로 다른 그룹으로 존재하였다. 이러한 결과는 두 서식지의 이화성 아황산염 환원효소를 가지고 있는 미생물의 군집구조는 확연히 다르고 각 서식지에 특이적인 황산염 환원 미생물이 존재함을 시사한다. The diversity of sulfate reducing bacteria was investigated in different depths of sediments in Lake Sihwa, Korea and Lake Aha, China by PCR amplification, denaturing gradient gel electrophoresis (DGGE) and clone libraries targeting dissimilatory sulfite redectase (dsr) gene. In the analysis of DGGE band patterns, the community compositions of dsr gene in the sediments of both lakes were significantly different whereas bands in all depths of each environment revealed similar patterns. Bands from Lake Sihwa were produced much more than those from Lake Aha, demonstrating a higher diversity of dsr gene in Lake Sihwa. Total 68 clones containing dsr gene were obtained to analyze their sequences. Sequences from the sediment of Lake Sihwa were affiliated to Deltaproteobacteria, the Gram-positive thermophilic sulfate reducers belonging to the genus Desulforomaculum and archaeal thermophilic SRB belonging to the genus Archaeoglobus, whereas sequences from the sediments of Lake Aha were related to genus Desulfotomaculum. Clones retrieved from sediment of Lake Sihwa revealed a higher numbers than those of Lake Aha, demonstrating a higher diversity of dsr gene in Lake Sihwa. Most of clones (59%) were distantly related to the known cultivated SRB with $60\sim65%$ of similarity, which were clustered only the sequences from the environments showed less than 90% similarity. These habitat specific sequences suggested that the clustered dsr sequences represent species or groups of species that were indigenous to these environments. This study showed that these lakes have a specific bacterial communities having dsr gene distinct from those in other environments such as soil and marine ecosystems around the world.

Community analysis of betaproteobacterial ammonia-oxidizing bacteria using the <i>amoCAB</i> operon

Junier, Pilar,Kim, Ok-Sun,Junier, Thomas,Ahn, Tae-Seok,Imhoff, Johannes F.,Witzel, Karl-Paul Springer-Verlag 2009 Applied microbiology and biotechnology Vol.83 No.1

<P>The genes and intergenic regions of the <I>amoCAB</I> operon were analyzed to establish their potential as molecular markers for analyzing ammonia-oxidizing betaproteobacterial (beta-AOB) communities. Initially, sequence similarity for related taxa, evolutionary rates from linear regressions, and the presence of conserved and variable regions were analyzed for all available sequences of the complete <I>amoCAB</I> operon. The gene <I>amoB</I> showed the highest sequence variability of the three <I>amo</I> genes, suggesting that it might be a better molecular marker than the most frequently used <I>amoA</I> to resolve closely related AOB species. To test the suitability of using the <I>amoCAB</I> genes for community studies, a strategy involving nested PCR was employed. Primers to amplify the whole <I>amoCAB</I> operon and each individual gene were tested. The specificity of the products generated was analyzed by denaturing gradient gel electrophoresis, cloning, and sequencing. The fragments obtained showed different grades of sequence identity to <I>amoCAB</I> sequences in the GenBank database. The nested PCR approach provides a possibility to increase the sensitivity of detection of <I>amo</I> genes in samples with low abundance of AOB. It also allows the amplification of the almost complete <I>amoA</I> gene, with about 300 bp more sequence information than the previous approaches. The coupled study of all three <I>amo</I> genes and the intergenic spacer regions that are under different selection pressure might allow a more detailed analysis of the evolutionary processes, which are responsible for the differentiation of AOB communities in different habitats.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s00253-009-1923-x) contains supplementary material, which is available to authorized users.</P>