B. Iron 1. Iron, a minor nutrient for plants, is often unavailable for uptake and deficiencies are common. Microbial role is very important. Under alkaline to neutral conditions, ferrous iron is unstable in presence of oxygen and is oxidized abiotically. Microorganisms can't compete.
Oxidation occurs as a result of different types of microbial activities.
Shows characteristics of growth. Organism often becomes coated with ferric hydroxide generated abiotically during process. Energy yield is small so large amount of material is transformed. In the process, copper, arsenic, nickel, cobalt and other minerals may also be oxidized. These were mined and smelted in early industrial age.