Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Microbial respiration and fermentation

The microbes use two general strategies to synthesize ATP respiration and fermentation. A respiring microbe captures the energy released when electrons are transferred from a reduced species in the environment to an oxidized species (Fig. 18.1). The reduced species, the electron donor, sorbs to a complex of redox enzymes, or a series of such complexes, located in the cell membrane. The complex strips from the donor one or more electrons, which cascade through a series of enzymes and coenzymes that make up the electron transport chain to a terminal enzyme complex, also within the cell membrane. [Pg.258]

This process of creating ATP, known as electron transport phosphorylation, then, involves two half-cell reactions, one at the electron donation site and the other where the electrons are accepted from the transport chain. Taking aerobic sulfide oxidation as an example, the donating species H2S(aq) gives up electrons, two at a time, to a series of redox complexes. With the loss of each pair of electrons, the sulfide oxidizes first to S°, then thiosulfate, sulfite, and finally sulfate. [Pg.259]

The electron donation half-reaction, the sum of the four donation steps, is [Pg.259]

The electrons, having passed through the transport chain to the terminal enzyme, are taken up by the reduction of dioxygen, [Pg.259]

In environments lacking a suitable external electron acceptor - such as dioxygen, sulfate, or ferric iron - respiration is not possible. Here, many organic compounds may be metabolized by fermenting microorganisms. Microbes of this class may create ATP by a direct coupling mechanism, using a process known as substrate level phosphorylation, SLP with an ion translocation mechanism like that employed by respirers, as already described or by a combination of SLP and ion translocation.1 [Pg.259]


In a series of papers, Jin and Bethke (2002 2003 2005 2007) and Jin (2007) derived a generalized rate expression describing microbial respiration and fermentation. They account in their rate model for an electron-donating half-cell reaction,... [Pg.263]


See other pages where Microbial respiration and fermentation is mentioned: [Pg.257]    [Pg.259]   


SEARCH



Fermentation and respiration

Microbial fermentation

Respiration, microbial

Respirators and

© 2024 chempedia.info