Question

Leptothrix is an example of iron bacteria. Which of the following statements best fit the iron bacteria?
A. They oxidise ferrous compounds to ferric oxides.
B. They are responsible for the preservation of iron rich artefacts and archaeological materials.
C. They cause rusting of iron.
D. They cause iron to be deposited in the liver of animals.

Answer 1

The Leptothrix is an iron oxidising bacteria. They are chemotrophs which derive nutrition by oxidising iron (II). They require sufficient oxygen and are found to live and proliferate in water.

Complete answer:
The organisms which use the chemical source to produce their food are known as chemoautotrophs. For example, iron oxidising bacteria called the Leptothrix. They can grow and live-in water containing very less concentration of iron. They oxidise ferrous compounds to ferric compounds. They require a sufficient amount of oxygen to carry out oxidation.
These bacteria live in the zone the transition of deoxygenated to oxygenated water takes place. When the oxygenated conditions are absent, these bacteria reduce the ferric to ferrous ions.
The preservation of iron rich artefacts is done by reducing the acid rain and also by applying certain types of paints which prevent the oxidation of iron.
The rusting of iron takes place when the water and oxygen oxidises the iron to form ferric oxide hydrated. It is a chemical change and is irreversible in nature.
The accumulation of iron in the liver is majorly by the causes like congenital or certain iron loading conditions. It leads to liver damage and cirrhosis.

The correct answer is option A.

Note –
Iron oxidising bacteria are present in the iron-rich fresh water where the organic content is low. They are gram negative and strictly aerobic. They look like fine hairs as is evident from the name.