State the important role of microorganisms

The important role of microorganisms was recognised as early as 1838, when J.B. Boussingeutt a French agricultural chemist observed that legumes could utilise the atmospheric nitrogen for their nutrition. It was further confirmed when, M.W. Beigerinch, a Dutch scientist, isolated bacteria from root nodules of legumes. Investigations have shown that soil is not an inert body but a medium pulsating with a large number of microbes that are always viable and active and thus full of life.  These organisms transform soil structure as part of their normal activities and add fertilizers and organic matter to the soil.