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Title: Photosystem II Water Oxidation: Mechanism, Efficiency and Flux in Diverse Oxygenic Phototrophs

Abstract

In one year, we pursued four aims: 1) extend the VZAD model to allow analysis of PSII chlorophyll fluorescence emission as modulated by interaction with the WOC (partial success); 2) compare the solar energy conversion efficiencies of PSII-WOCs from intact cells, isolated thylakoid membranes and PSII core complexes and crystals from cyanobacterium Thermosynechococcus elongatus (collaboration with Lawrence Berkeley National Laboratory; some success after changing collaborator); 3) determine whether PSIIs can store light energy by pumping protons across the thylakoid membrane (PSII-cyclic electron flow) and how it is regulated within the green alga Chlorella ohadii (collaboration with the Hebrew University of Jerusalem; some success); and 4) genetically replace the native PSII-D1 protein subunit from a higher plant with two cyanobacterial D1 isoforms to test whether their functional advantages in growth and photoprotection can be transferred (collaboration with Rutgers University; success).

Authors:
 [1];  [1];  [1]
  1. Rutgers Univ., Piscataway, NJ (United States)
Publication Date:
Research Org.:
G. Charles Dismukes (Rutgers University)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
OSTI Identifier:
1418262
Report Number(s):
DOE-RUTGERS-05354
DOE Contract Number:
SC0005354
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 14 SOLAR ENERGY; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Photosystem II; bicarbonate; cyclic electron flow; water oxidation; carbon sequestration

Citation Formats

Dismukes, Gerard Charles, Ananyev, Gennady, and Gates, Colin. Photosystem II Water Oxidation: Mechanism, Efficiency and Flux in Diverse Oxygenic Phototrophs. United States: N. p., 2018. Web. doi:10.2172/1418262.
Dismukes, Gerard Charles, Ananyev, Gennady, & Gates, Colin. Photosystem II Water Oxidation: Mechanism, Efficiency and Flux in Diverse Oxygenic Phototrophs. United States. doi:10.2172/1418262.
Dismukes, Gerard Charles, Ananyev, Gennady, and Gates, Colin. 2018. "Photosystem II Water Oxidation: Mechanism, Efficiency and Flux in Diverse Oxygenic Phototrophs". United States. doi:10.2172/1418262. https://www.osti.gov/servlets/purl/1418262.
@article{osti_1418262,
title = {Photosystem II Water Oxidation: Mechanism, Efficiency and Flux in Diverse Oxygenic Phototrophs},
author = {Dismukes, Gerard Charles and Ananyev, Gennady and Gates, Colin},
abstractNote = {In one year, we pursued four aims: 1) extend the VZAD model to allow analysis of PSII chlorophyll fluorescence emission as modulated by interaction with the WOC (partial success); 2) compare the solar energy conversion efficiencies of PSII-WOCs from intact cells, isolated thylakoid membranes and PSII core complexes and crystals from cyanobacterium Thermosynechococcus elongatus (collaboration with Lawrence Berkeley National Laboratory; some success after changing collaborator); 3) determine whether PSIIs can store light energy by pumping protons across the thylakoid membrane (PSII-cyclic electron flow) and how it is regulated within the green alga Chlorella ohadii (collaboration with the Hebrew University of Jerusalem; some success); and 4) genetically replace the native PSII-D1 protein subunit from a higher plant with two cyanobacterial D1 isoforms to test whether their functional advantages in growth and photoprotection can be transferred (collaboration with Rutgers University; success).},
doi = {10.2172/1418262},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2018,
month = 1
}

Technical Report:

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  • Analyses were made of TMPD oxidation kinetics following a short actinic flash by PS 2 membranes depleted of one or more extrinsic proteins. A high correlation between O/sub 2/ evolution capacity and a slow (approx.60 ms) and fast (approx.600 ..mu..s) component was observed with native preparations having a PS 2 unit of 200 to 230 Chls and approx.4 Mn/200 Chl. Depletion of the 17,23,33 kDa proteins by CaCl/sub 2/ caused no less of Mn, less than or equal to 80% decoupling of the PS 2 trap/S-States, high reactivity of the Mn-complex with TMPD, and possibly a slowing of the 600more » ..mu..s component. Depletion of the 17,23 kDa proteins by NaCl caused approx.25% decoupling which was reversed by reconstitution without proportionate increase in S/sub 2/ abundance - a consequence of (minimally) two different charge loss reactions. Chloride depletion of 17,23 kDa depleted membranes resulted in additional decoupling, a reactivity of the Mn-complex with TMPD and significant inactivation of one charge loss reaction. Component 'C', perhaps identifiable with Cyt b/sub 559/, was implicated to participate in one of the charge loss reactions. 49 refs., 8 figs., 2 tabs.« less
  • The oxidation of Cr-Fe alloys (Cr content of 5, 10, 15, 20, and 25 wt.%) in a water vapor-argon atmosphere was studied at 700, 900, and llOO/sup o/C. A mechanism for the oxidation process is suggested in the form of wustite decomposition at the outer-inner scale layer boundary, giving rise to Fe/sup 2+/ diffusion to the outer layer and O/sup 2/diffusion to the alloy-oxide interface. (C.J.G.)
  • Ignition delay times for the hydrogen/oxygen/carbon dioxide/argon system were obtained behind reflected shock waves. A detailed kinetic mechanism modeled the experimental hydrogen/oxygen data, Skinner and Ringrose's high-pressure data, and Slack and Grillo's hydrogen/air data. A carbon dioxide chaperon efficiency of 7.0 +/- 0.2 was determined. The reaction pathway H/sub 2/O yields H/sub 2/O/sub 2/ yields OH yields H was required to model the high-pressure data. It is suggested that some of the lowest temperature data points (1.0 and 0.5 atm) for Slack and Grillo's hydrogen/air experiments are in error. It was found that the technique of simplifying a detailed kineticmore » mechanism for a limited range of experimental data may render the model useless for other test conditions.« less
  • The ''Griess Correlation,'' in which the thickness of the corrosion product on aluminum alloy surfaces is expressed as a function of time and temperature for high-flux-reactor conditions, was rewritten in the form of a simple, general rate equation. Based on this equation, a computer program that calculates oxide-layer thickness for any given time-temperature transient was written. 4 refs.
  • This report discusses the replacement of water by carbon dioxide in both the quench stream and the supercritical water oxidation (SCWO) reactor feed in order to reduce the energy utilization in the process. FLUENT was used to generate the input requirements and ASPEN PLUS was used to model the SCWO process. Simulations were made for normal MODAR operating conditions (baseline case) and two other cases replacing water by carbon dioxide. The basis for and assumptions used in the simulation are given. Economic evaluations were made and costs were compared with the baseline case and a case with 60% replacement ofmore » water by carbon dioxide. The equipment cost is almost the same. However, the case with replacement of water by carbon dioxide reduces the energy requirement in the end process by a factor of three, which is a significant energy savings in the operation. Also, the injection of carbon dioxide into the SCWO reactor feed is expected to reduce corrosion and makes salt particles non-sticky. However, these advantages need to be confirmed by experiment.« less