Without bacteria we wouldn’t have skyscrapers…

Periodic table Number :26   /    known as element  “Fe” (from latin Ferrum)

Iron is the most common element on earth by mass, it’s found in rocks and living things.  It’s in our blood which is why its red in colour due the reaction with oxygen when transferred from our lungs into the haemoglobin.  But how did it get there in the first place?  To understand this we need to take a big step back in time, 1.8 billion years ago, when atoms of iron were floating around in the oceans.  Bacteria capable of photosynthesis releasing oxygen into the sea enabled iron to be converted into hematite and magnetite minerals which sank to the sea floor.  This was fundamental to the geological process in forming iron deposits which were later covered by other minerals and compressed into rock over millions of years.

iron ore mine in Australia

Iron ore was first used in the near east and spread around the Mediterranean in all directions expanding populations as a result of more efficient tools and the ‘iron age’ began.   The end of the bronze age around 1200BC was heralded by the development of iron smelting (heating iron ore with coal) which in turn lead to the birth to the industrial revolution in Northern Europe changing societies rapidly with mass production methods.

ancient iron smelting technique in Rwanda

Skyscrapers rely on steel (99% iron 1% carbon) to give the structure enough strength to build as high as the Burj Khalifain Dubai at 828 meters, all thanks to bacteria

Today we can see chemotrophic bacteria which get their energy by oxidising molecules of iron and therefore thrive in areas rich in iron deposits so the bacterial cycle continues. .  When you see orange coloured stream beds you are seeing the specialised iron oxidising bacteria at work.

Humans need iron or we become anaemic (tired and lacking vitality) and we get this by eating food containing iron.  Humans are 10%  bacteria (by mass) and those bacteria too need iron and they have specialised ways of harvesting the iron they need from their human host. “Iron is the single most important micronutrient bacteria need to survive,” (Doyle, 2008) and without bacteria humans can’t survive.  This is one of the many symbiotic relationships animals and humans have with bacteria.

bacteria that feed on iron


Doyle, 2008: Journal of Bacteriology (volume 190, issue 16) published by the American Society for Microbiology. https://www.sciencedaily.com/releases/2008/07/080731140223.htm

Iron-Oxidizing Bacteria: https://www.researchgate.net/publication/44689809_Iron-Oxidizing_Bacteria_An_Environmental_and_Genomic_Perspective