Does the Tree of Life need to be redrawn? New groups of 'weird' bacteria are unlike anything discovered before The tree of life on Earth may need to be redrawn after scientists discovered new groups of bacteria totally unlike anything discovered before.Researchers have identified 35 new phyla of bacteria they believe sit on a branch of the evolutionary tree that is completely separate from other types of bacteria.Some of the new bacteria are the smallest life forms yet to be discovered on Earth “ just 400 nanometres across, about 250 times smaller than the width of a human hair.Professor Jill Banfield, an environmental scientist at the University of California in Berkeley who led the work, said: 'This is a new view of the tree of life.'These new major features on the tree of life mean that it probably won't be the simple three-domain view we have now.'Currently the taxonomic system used by scientists to classify living organisms divides into three main domains “ bacteria, Archaea “ primitive bacteria-like microbes “ and eurkaryotes, which are all multicellular organisms including plants, animals and fungi.While the eukaryotic domain is fairly well classified into 35 separate phyla, those of bacteria and Archaea are far less well understood.Phyla is the taxonomic classification that sits just below the domains. So within the eukaryotes, the phylum Chordata includes humans and all other vertebrates.Many microbes that grow in the natural world, however, cannot be grown in the laboratory, meaning scientists have struggled to study them in detail.Now in a paper published in the journal Nature, Professor Banfield and her colleagues sequenced the genomes of organisms found in ground water at a site beside the Colorado river in Rifle Colorado.Using filters to catch the bacteria they then used shotgun-sequencing on the DNA of the microbes they found and then analysed them with a technique known as metagenomics.They then assembled the millions of DNA pieces into eight complete bacterial genomes from four new and one previously studied phyla.They also produced draft genomes “ more than 90 per cent complete “ for a further 789 other bacteria.In total they discovered bacteria from 35 new phyla that appeared very unlike any previously studied bacteria.Professor Banfield and her colleagues found the new bacteria they discovered appear to use a simple process of fermentation to make the energy they need.They also have unusual ribosomes, the protein-based machinery that translate genetic information into proteins.They have placed them into an entirely new branch of the tree of life they have called the 'candidate phyla radiation' due to their similarities to each other.They estimate there could be more than 250 phyla in this radiation and the new groups make up more than 15 percent of all known groups or phyla of bacteria.The work highlights the sheer diversity of life that is still to be discovered by scientists.These new phyla were found from just one site using samples of groundwater in Colorado but many more could exist in soils, rivers, oceans and even deep underground around the world.It comes after the same group of scientists identified nine new groups of Archaea, which they say could also form a new branch of the tree of life.Christopher Brown, a microbiologist who was part of the team who took part in the study at the University of California Berkeley, said: 'We were really surprised to find how diverse these groups are within the bacterial domain, and just how consistently different the organisms within this radiation are from the rest of bacteria.'No one had been able to put all the pieces together before.'The differences between the newly discovered bacteria and other known bacteria may be part of the reason why they are so hard to grow in the laboratory.They have extremely small genomes and appear to be 'stripped down' forms of life with just enough genes needed to survive.There are an estimated 100 bacterial phyla, but just 29 have species that will grow in laboratory cultures.The team has now named 20 the new phyla they identified after award-winning microbiologists and one was called Berkelbacteria - after University of California Berkeley.Mr Brown added: 'I think what this is telling us is that a large part of bacteria and bacterial lifestyles are very different from what we thought before.'There is a lot of biology that we haven't been able to understand from our current methods.'