assimilatory sulfate reduction

(noun)

The reduction of 3'-Phosphoadenosine-5'-phosphosulfate, a more elaborated sulfateester, leads also to hydrogen sulfide, the product used in biosynthesis (e.g., for the production of cysteine because the sulfate sulfur is assimilated).

Related Terms

Examples of assimilatory sulfate reduction in the following topics:

  • The Sulfur Cycle

    • Plants and microbes assimilate sulfate and convert it into organic forms.
    • Lots of bacteria reduce small amounts of sulfates to synthesize sulfur-containing cell components; this is known as assimilatory sulfate reduction.
    • By contrast, the sulfate-reducing bacteria considered here reduce sulfate in large amounts to obtain energy and expel the resulting sulfide as waste.
    • This process is known as dissimilatory sulfate reduction.
    • In a sense, they breathe sulfate.

  • Sulfate and Sulfur Reduction

    • Sulfate reduction is a type of anaerobic respiration that utilizes sulfate as a terminal electron acceptor in the electron transport chain.
    • Sulfate reduction is a type of anaerobic respiration that utilizes sulfate as a terminal electron acceptor in the electron transport chain.
    • The hydrogen produced during fermentation is actually what drives respiration during sulfate reduction.
    • Many bacteria reduce small amounts of sulfates in order to synthesize sulfur-containing cell components; this is known as assimilatory sulfate reduction.
    • Outline the process of sulfate and sulfur reduction including its various purposes

  • Electron Donors and Acceptors in Anaerobic Respiration

    • Instead, molecules such as sulfate (SO42-), nitrate (NO3-), or sulfur (S) are used as electron acceptors.
    • Nitrate, like oxygen, has a high reduction potential.
    • Sulfate reduction uses sulfate (SO2−4) as the electron acceptor, producing hydrogen sulfide (H2S) as a metabolic end product.
    • Sulfate reduction is a relatively energetically poor process, and is used by many Gram negative bacteria found within the δ-Proteobacteria.
    • Sulfate reduction requires the use of electron donors, such as the carbon compounds lactate and pyruvate (organotrophic reducers), or hydrogen gas (lithotrophic reducers).

  • Balancing Redox Equations

    • An example is given below of the reaction of iron(III) sulfate with magnesium.
    • Notice that the sulfate ion (SO42-) is ignored.
    • Reduction: $6H^+ + BiO_3^- \rightarrow Bi^{3+} + 3H_2O$ (Bi goes from a +5 to a +3)
    • Reduction: 3 e− + 2 H2O + MnO4− → MnO2 + 4 OH−
    • An alternative method for balancing reduction/oxidation (redox) reactions.

  • Archaeoglobus

    • Archaeoglobus are sulfate-reducing archaea, coupling the reduction of sulfate to sulfide with the oxidation of many different organic carbon sources, including complex polymers.
    • Archaeoglobus are lithotrophs, and can be either autotrophic or heterotrophic.The archaeoglobus strain A. lithotrophicus are lithoautotrophs, and derive their energy from hydrogen, sulfate and carbon dioxide.

  • Predicting if a Metal Will Dissolve in Acid

    • If you immerse a piece of metallic zinc in a solution of copper sulfate, the surface of the zinc quickly becomes covered with a coating of finely divided copper.
    • The activity series has long been used to predict the direction of oxidation-reduction reactions.
    • These values can be determined using standard reduction potentials, which can often be looked up.
    • Set up the oxidation and reduction half-reactions with their cell potential:
    • Predict whether a metal will dissolve in acid, given its reduction potential

  • Predicting the Products of Electrolysis

    • Oxidation of ions or neutral molecules occurs at the anode, and reduction of ions or neutral molecules occurs at the cathode.
    • We take two copper electrodes and place them into a solution of blue copper sulfate (CuSO4) and then turn the current on.
    • Two copper electrodes are placed in a solution of blue copper sulfate and are connected to a source of electrical current.

  • Microbial Ore Leaching

    • In the process, free electrons are generated and used for the reduction of oxygen to water which produces energy in the bacterial cell.
    • The net products of the reaction are soluble ferrous sulfate and sulfuric acid.

  • Oxidation of Reduced Sulfur Compounds

    • Biochemically, reduced sulfur compounds are converted to sulfite (SO2−3) and, subsequently, sulfate (SO2−4) by the enzyme sulfite oxidase.
    • Some organisms, however, accomplish the same oxidation using a reversal of the APS reductase system used by sulfate-reducing bacteria (see above).
    • Marine autotrophic Beggiatoa species are able to oxidize intracellular sulfur to sulfate.
    • The reduction of elemental sulfur frequently occurs when oxygen is lacking.

  • Manganese

    • The most stable oxidation state (oxidation number) for manganese is 2+, which has a pale pink color, and many manganese(II) compounds are common, such as manganese(II) sulfate (MnSO4) and manganese(II) chloride (MnCl2).
    • The Mn-SOD enzyme is probably one of the most ancient, as nearly all organisms living in the presence of oxygen use it to deal with the toxic effects of superoxide formed from the 1-electron reduction of dioxygen.
    • Predict the oxidation or reduction propensity of a manganese species given its formula or oxidation state.