ROGER PRINCE - Academia.edu (original) (raw)

Papers by ROGER PRINCE

Plant Physiology, Mar 1, 2003

In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in i... more In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower, and selenate predominates. Seleno-Cys methyltransferase is the enzyme responsible for the biosynthesis of Se-methylseleno-Cys from seleno-Cys and S-methyl-methionine. Seleno-Cys methyltransferase is found to be expressed in A. bisulcatus leaves of all ages, and thus the biosynthesis of Se-methylseleno-Cys in older leaves is limited earlier in the metabolic pathway, probably by an inability to chemically reduce selenate. A comparative study of sulfur (S) and Se in A. bisulcatus using x-ray absorption spectroscopy indicates similar trends for oxidized and reduced Se and S species, but also indicates that the proportions of these differ significantly. These results also indicate that sulfate and selenate reduction are developmentally correlated, and they suggest important differences between S and Se biochemistries.

Frontiers in Marine Science, Jan 28, 2021

Environmental Science and Pollution Research, Aug 13, 2013

Inorganic Chemistry, Feb 14, 2008

Applied and Environmental Microbiology, Nov 1, 2000

Cultures of a purple nonsulfur bacterium, Rhodobacter sphaeroides, amended with ϳ1 or ϳ100 ppm se... more Cultures of a purple nonsulfur bacterium, Rhodobacter sphaeroides, amended with ϳ1 or ϳ100 ppm selenate or selenite, were grown phototrophically to stationary phase. Analyses of culture headspace, separated cells, and filtered culture supernatant were carried out using gas chromatography, X-ray absorption spectroscopy, and inductively coupled plasma spectroscopy-mass spectrometry, respectively. While selenium-amended cultures showed much higher amounts of SeO 3 2؊ bioconversion than did analogous selenate experiments (94% uptake for SeO 3 2؊ as compared to 9.6% for SeO 4 2؊ -amended cultures from 100-ppm solutions), the chemical forms of selenium in the microbial cells were not very different except at exposure to high concentrations of selenite. Volatilization accounted for only a very small portion of the accumulated selenium; most was present in organic forms and the red elemental form.

Biochemical Journal, Apr 15, 1989

Hydrogenase II from Clostridium pasteurianum contains three different iron-sulphur clusters. Two ... more Hydrogenase II from Clostridium pasteurianum contains three different iron-sulphur clusters. Two are [4Fe-4S]12`1 +) clusters, whereas the other, which is thought to be the site of interaction with H2 and is known as the 'H cluster', is of unknown structure and possesses unusual spectroscopic properties. Analysis of the iron e.x.a.f.s. spectra shows that the H cluster contains iron co-ordinated mostly to sulphur and possesses 2.8 A (1 A = 0.1 nm) Fe--Fe separations when oxidized and 3.3 A Fe--Fe separations when reduced with H2' The data suggest that the reduced H cluster represents

Journal of the American Chemical Society, Jul 4, 2007

Biochemical Journal, Nov 15, 1988

Applied and Environmental Microbiology, 1999

Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343°C middle-... more Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343°C middle-distillate (diesel range) fraction of Oregon basin (OB) crude oil. OB oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. Gas chromatography (GC), flame ionization detection, and GC sulfur chemiluminesce detection analysis were used to qualitatively evaluate the effect of Rhodococcus sp. strain ECRD-1 treatment on the hydrocarbon and sulfur content of the oil, respectively. Total sulfur was determined by combustion of samples and measurement of released sulfur dioxide by infrared absorption. Up to 30% of the total sulfur in the middle distillate cut was removed, and compounds across the entire boiling range of the oil were affected. Sulfur K-edge X-ray absorption-edge spectroscopy was used to examine the chemical state of the sulfur remaining in the treated OB oil. Approximately equal amounts of thiophenic and sulfidic sulfur compounds were removed by ECRD-1 treatment, and over 50% of the sulfur remaining after treatment was in an oxidized form. The presence of partially oxidized sulfur compounds indicates that these compounds were en route to desulfurization. Overall, more than two-thirds of the sulfur had been removed or oxidized by the microbial treatment.

Photosynthetica, Sep 1, 2015

We present here a Memoir of Colin Allen Wraight (19452014), a central figure in photosynthetic e... more We present here a Memoir of Colin Allen Wraight (19452014), a central figure in photosynthetic electron transfer research, particularly in photosynthetic bacteria, who died of leukemia, in Urbana, Illinois, on July 10, 2014. Born in London, England, on November 27, 1945, he had only recently retired from his position as a Professor in Biochemistry, Biophysics & Quantitative Biology, and Plant Biology at the University of Illinois at Urbana-Champaign (UIUC). Wraight was known especially for his pioneering studies on electron and proton transfer in the photochemical reaction center, and for his careful quantitation of the remarkable quantum efficiency of this device in photosynthetic bacteria. A detailed Tribute is being published simultaneously in Photosynthesis Research, another Springer journal (Govindjee et al. 2015); this Memoir is based on the first part of that Tribute. Colin Wraight completed both his undergraduate and graduate degrees at the University of Bristol (19641971), the latter in the laboratory of Antony (Tony) R. Crofts. He was the first (along with J. Baz Jackson) of Tony's graduate students. Those were heady days, at the height of the great Chemiosmotic Wars, and the Crofts lab was on the frontlines. Colin did some beautiful work including determining the dependence of (chlorophyll) fluorescence quenching (Wraight and Crofts 1970) on the chloroplast ΔpH, and building an intimidating phosphoroscope with which he established the dependence of delayed light emission (DLE) from chlorophyll (Wraight and Crofts 1971) on both components of the proton motive force (pH and ). These results emphasized the vectorial nature of the initial photochemical reactions as Peter Mitchell had proposed. (We all know that Mitchell, in 1978, received the Nobel Prize in Chemistry for his hypothesis of chemiosmosis.) Bristol was not far from Glynn House in Bodmin, and interactions with Peter Mitchell were a regular occurrence. Colin's PhD examiner was Robert (Robin) Hill, and the 'examination' included Robin's demonstration of a "glow of light" from a chlorophyll solution in a darkened fume hood. Colin spent a postdoctoral year in Louis (Lou) N. M. Duysen's laboratory at the State University in Leiden (19711972), following up his work on DLE . He then moved to Roderick (Rod) K. Clayton's lab at Cornell University, in Ithaca, NY, for another stint as a postdoc (19721974). In Rod's lab he forswore chloroplasts to concentrate on photosynthetic bacteria, a decision he rarely revisited. In Ithaca he made one especially important (and well-cited) measurement : that the absolute quantum efficiency of the photochemical reaction center of what is now known as Rhodobacter sphaeroides was 1.02 ± 0.04. And what a number that is: it is as close to a perfect as Nature could ever have. [See an outstanding Tribute by Wraight (2014), on the life of Rod Clayton.] Colin had a brief sojourn on the faculty at the University of California (UC), Santa Barbara, and in 1975 he moved to the University of Illinois at Urbana-Champaign (UIUC), IL. He joined the faculty as an Assistant Professor in the Departments of Plant Biology, and of Physiology and Biophysics. In 1999 he moved to the Department of Biochemistry, which was his permanent home until the end. Perhaps not serendipitously, Tony Crofts had moved to the UIUC in 1978,

Photosynthesis Research, Jul 23, 2015

Colin Allen Wraight, a central figure in photosynthetic electron transfer research since the 1970... more Colin Allen Wraight, a central figure in photosynthetic electron transfer research since the 1970s, died in Urbana, Illinois, on July 10, 2014. Born in London, England, on November 27, 1945, he had only recently retired from his position as a Professor in Biochemistry, Biophysics & Quantitative Biology, and Plant Biology at the University of Illinois at Urbana-Champaign. Wraight was known especially for his pioneering studies on electron and proton transfer in the photochemical reaction center, and for his careful quantitation of the remarkable quantum efficiency of this device.

Environmental Science & Technology, May 17, 2022

Springer eBooks, 2018

Hydrocarbons have been part of the biosphere for millions of years, and a diverse group of prokar... more Hydrocarbons have been part of the biosphere for millions of years, and a diverse group of prokaryotes has evolved to use them as a source of carbon and energy. To date, the vast majority of formally defined genera are eubacterial, in 7 of the 24 major phyla currently formally recognized by taxonomists (Tree of Life, http://tolweb.org/Eubacteria. Accessed 1 Sept 2017, 2017); principally in the Actinobacteria, the Bacteroidetes, the Firmicutes, and the Proteobacteria. Some Cyanobacteria have been shown to degrade hydrocarbons on a limited scale, but whether this is of any ecological significance remains to be seen – it is likely that all aerobic organisms show some basal metabolism of hydrocarbons by nonspecific oxygenases, and similar “universal” metabolism may occur in anaerobes. This chapter focuses on the now quite large number of named microbial genera where there is reasonably convincing evidence for hydrocarbon metabolism. We have found more than 320 genera of Eubacteria, and 12 genera of Archaea. Molecular methods are revealing a vastly greater diversity of currently uncultured organisms – Hug et al. (Nat Microbiol 1:16048, 2016) claim 92 named bacterial phyla, many with almost totally unknown physiology – and it seems reasonable to believe that the catalog of genera reported here will be substantially expanded in the future.

169, 247- 250 5 Tien, M and Karl T K (1984) Proc Natl Acad Set USA 81. 2280-2284 6 Gold. M H. Kuw... more 169, 247- 250 5 Tien, M and Karl T K (1984) Proc Natl Acad Set USA 81. 2280-2284 6 Gold. M H. Kuwahara, M, Cluu, A A and Glenn, J K (1984)Arch Bmchem Btophys 234,353-362 7 Renganathan, V and Gold, M H (1986) Btochenustry 25, 1626--1631 8 Dunford.H B (1982)Adv Innrg Chem. 4,4-- 68 9 Schoemaker. H E, Harvey, P J, Bowen, R M and Palmer, J M (1985) FEBS Lett 183, 7-12 10 Hammel, K E, Kalyanaraman, B and Kdrk,

Trends in Biochemical Sciences, May 1, 1988

Proceedings, Mar 1, 2011

ABSTRACT Many light-to-medium crude and fuel oils will spread rapidly on open water to an average... more ABSTRACT Many light-to-medium crude and fuel oils will spread rapidly on open water to an average thickness < 1 mm and perhaps < 0.1 mm. Effective application of dispersants results in the rapid transport of oil as small droplets into the water column. Simple calculations predict that the turbulence of 1 m waves will rapidly entrain dispersed oil into the top 1 m of the water column, diluting a 1 mm thick slick to a concentration of 1,000 ppm and a 0.1 mm slick to 100 ppm. Within a short period of time (likely less than 1 day), a dispersed oil plume in the open sea will mix into the top 10 m (or more) of the water column to give average oil concentrations of 100 ppm for the 1 mm thick slick and 10 ppm for the 0.1 mm thick slick, and dilution will continue as time proceeds. Measurements conducted during actual spill events support these calculations. Average concentrations measured in dispersed oil plumes 1 m below the surface are in the range of 100 ppm oil or less. Dilution to concentrations below 5 ppm was observed 500 m downstream when dispersants were injected at the point of release (1500 m depth) during the recent Deepwater Horizon Spill in the Gulf of Mexico. Each dispersed oil droplet is a concentrated food source that is rapidly colonized and degraded by marine bacteria. For ecological relevance, lab-based biodegradation studies of dispersed oil must account for the rates of dilution observed in the open sea. Biologically available nitrogen is often relatively low in marine environments, and hydrocarbon loadings of >10 ppm in a closed system will likely result in low rates and extent of biodegradation if natural seawater is the test solution. This might be overcome by the judicious addition of nutrients, but such additions may well change the composition of the indigenous microbial flora, and should be done with caution. If the goal is to simulate actual marine biodegradation, dispersed oil biodegradation studies should be conducted at very low hydrocarbon loadings to provide C/N/P ratios typically observed during actual response operations.