Reduction of oxidized state of elements. May serve as electron acceptor in anaerobic environments but this is not required for reduction to occur. Raises the pH. 5. Complexation of metals with microbially-produced organic ligands , e.g. chelates to increase solubility of mineral. Changing total quantity of element in soil a. fixation of volatile to cellular material b. causing volatilization by converting molecule to gaseous forms.
Eukaryotes have their electron transport system internally, in mitochondria.
This limits the kinds of substances they can use as donors and acceptors. However, physical contact with the substrate is required. We will briefly go through each major category of microbial reaction and give examples. In the release of C and N from organic matter, there will obviously be release of other elements present at much lower concentrations in the organic matter. Members of Pedomicrobium , Metallogenium , and Seliberia attack iron-organic compounds of humus and metabolism results in deposition of ferric hydroxide that coats bacteria.