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Title: Enzymes of respiratory iron oxidation. Progress report, March 1990--June 1992

Abstract

This report describes experimental progress in characterizing and identifying redox proteins in a number of iron-oxidizing bacteria. Sections of the paper are entitled (1) In Situ electrolysis was explored to achieve enhanced yields of iron-oxidizing bacteria, (2)Structure/function studies were performed on redox-active biomolecules from Thiobacillus ferrooxidans, (3) Novel redox-active biomolecules were demonstrated in other iron autotrophs, and (4) New probes of metalloprotein electron-transfer reactions were synthesized and characterized.

Authors:
Publication Date:
Research Org.:
Meharry Medical Coll., Nashville, TN (United States). Dept. of Biochemistry
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10149887
Report Number(s):
DOE/ER/13339-8
ON: DE93013862
DOE Contract Number:
FG05-85ER13339
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1992]
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 09 BIOMASS FUELS; THIOBACILLUS FERROXIDANS; REDOX REACTIONS; METALLOPROTEINS; FRACTIONATION; BIOCHEMICAL REACTION KINETICS; CYTOCHROMES; PROGRESS REPORT; BIOTECHNOLOGY; OXIDOREDUCTASES; ELECTROPHORESIS; 550200; 550500; 090900; BIOCHEMISTRY; METABOLISM; PROCESSING

Citation Formats

Blake, R. II. Enzymes of respiratory iron oxidation. Progress report, March 1990--June 1992. United States: N. p., 1992. Web. doi:10.2172/10149887.
Blake, R. II. Enzymes of respiratory iron oxidation. Progress report, March 1990--June 1992. United States. doi:10.2172/10149887.
Blake, R. II. Thu . "Enzymes of respiratory iron oxidation. Progress report, March 1990--June 1992". United States. doi:10.2172/10149887. https://www.osti.gov/servlets/purl/10149887.
@article{osti_10149887,
title = {Enzymes of respiratory iron oxidation. Progress report, March 1990--June 1992},
author = {Blake, R. II},
abstractNote = {This report describes experimental progress in characterizing and identifying redox proteins in a number of iron-oxidizing bacteria. Sections of the paper are entitled (1) In Situ electrolysis was explored to achieve enhanced yields of iron-oxidizing bacteria, (2)Structure/function studies were performed on redox-active biomolecules from Thiobacillus ferrooxidans, (3) Novel redox-active biomolecules were demonstrated in other iron autotrophs, and (4) New probes of metalloprotein electron-transfer reactions were synthesized and characterized.},
doi = {10.2172/10149887},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 31 00:00:00 EST 1992},
month = {Thu Dec 31 00:00:00 EST 1992}
}

Technical Report:

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  • This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies on whole cells using the oxygen electrode; and to identify, separate, purify, and characterize the individual cellular components.
  • Slagging combustors with injected lime or limestone are being considered as replacements for conventional coal burners. They have advantages in that they can be staged to reduce NO{sub x} and SO{sub x} emissions. Iron oxide, as an alternative to lime or limestone may be effective not only as a desulfurizing agent, but, under the right conditions of oxygen potential, it can act as a flux to produce a glassy slag. This glassy slag should be dense and environmentally inert. In this reporting period, the thermodynamic conditions are determined for the operation of the first stage of a combustor which wouldmore » have as its feed six types of coals. The calculations are made for the four phase equilibrium: FeO(wustite)/Fe/Liquid/Gas over the temperature range 950{degrees} to 1300{degrees}C. The minimum dosage of iron oxide required at equilibrium an the calculated maximum percent sulfur removal are reported. Also given are the expected pounds of S0{sub 2} per million Btu of heat evolution calculated for complete combustion. These preliminary results indicate in the Fe-O-S system that higher temperatures give better results approaching 96 percent sulfur removal from a coal containing (on a dry basis) 3.29% by weight sulfur. In the prior reporting period, a comparison is made between iron oxide and lime as a desulfurizing agent. With lime, the thermodynamic conditions were chosen: a set of conditions where the compound calcium sulfide is the product and a set of conditions where calcium sulfate is the product. The temperature limits of the sulfate forming and sulfide forming reactions were defined.« less
  • We have demonstrated in this work (1) that methane is readily activated at mild conditions (100{degree}C, 1 torr) over a relatively noble metal, Pd. This was observed using a stepped and kinked Pd(679) crystal (1), and other crystal faces are now being investigated to establish whether the cracking of the C-H bond of methane on Pd is structure sensitive or structure insensitive. Oxygen chemisorption is extremely structure sensitive: weakly bonded, highly reactive oxygen overlayers form on Pd(100) surface (2), while strongly bonded, moderately reactive oxygen overlayers form on Pd(111) and Pd(679). Reaction of the weakly bonded oxygen with surface carbidemore » gives rise to CO{sub 2} over clean Pd(100) but to CO over halogen-doped Pd(100) (3--5). The effect of halogens is primarily ensemble-controlling, or oxygen-supply restricting, but long range influence of surface Cl on the strength of the Pd-O bond has also been observed (3). Because the overall chemistry of methane activation with the subsequent oxidation gives rise to the very important oxidative reforming CH{sub 4} + 1/2 O{sub 2} {yields}{sub Pd/Cl} CO + 2 H{sub 2}, Pd/Cl we plan to continue our study of this reaction in detail over Pd(100) (completed), Pd(111) (initiated), Pd(311) (initiated), Pd(110) (to be initiated), and Pd(679) (completed), without and with the halogen modifiers.« less
  • This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies on whole cells using the oxygen electrode; and to identify, separate, purify, and characterize the individual cellular components.
  • This report describes experimental progress in characterizing and identifying redox proteins in a number of iron-oxidizing bacteria. Sections of the paper are entitled (1) In Situ electrolysis was explored to achieve enhanced yields of iron-oxidizing bacteria, (2)Structure/function studies were performed on redox-active biomolecules from Thiobacillus ferrooxidans, (3) Novel redox-active biomolecules were demonstrated in other iron autotrophs, and (4) New probes of metalloprotein electron-transfer reactions were synthesized and characterized.