what is the role of micro organisms in decomposition?

Answer 1

Micro-organisms (most frequently bacteria) are often integrally involved in the chemical alteration of minerals. Minerals, or intermediate products of their decomposition, may be directly or indirectly necessary to their metabolism. The dissolution of sulphide minerals under acidic conditions (ARD), the precipitation of minerals under anaerobic conditions, the adsorption of metals by bacteria or algae, and the formation and destruction of organometallic complexes are all examples of indirect micro-organism participation. Where minerals are available as soluble trace elements, serve as specific oxidizing substrates, or are electron donors/acceptors in oxidation-reduction reactions, they may be directly involved in cell metabolic activity.

There are three categories of oxidation-reduction reactions for minerals with micro-organisms:

Oxidation by autotrophic (cell carbon from carbon dioxide) or mixotrophic (cell carbon from carbon dioxide or organic matter) organisms. Energy derived from the oxidation reaction is utilized in cell synthesis.

Electron acceptance by minerals (reduction) for heterotrophic (cell carbon from organic matter) and mixotrophic bacteria. Chemical energy is used to create new cell material from an organic substrate.

Electron donation by minerals (oxidation) for bacterial or algal photosynthesis (reaction is fuelled by photon energy).

Answer 2

Microorganisms - especially bacteria and fungi, are responsible for decomposition and you should be happy about this. If organic matter never decomposed there would not be cycling of nutrients needed by primary producers, and the planet's food-webs would have vanished long ago because of lack of food. In fact regarding these food webs the production of these decomposer organisms feeds many other small organisms that live in soils and sediments.

Answer 3

Microorganisms secrete enzymes that break down organic molecules. Then the microorganisms absorb the digested material.