New bacteria phylum discovered in hospital sink


Normally, you think of new kinds of life being found in remote corners of the rainforest or some other exotic location, not right under our noses. Researchers have recently announced the discovery of a new, genetically weird, phylum of bacteria (Kingdom > Phylum > Class > Order > Family > Genus > Species, if its been a while since you’re last bio class), though, found living in the drain of hospital sink.

Now some researchers have managed to generate a genome sequence from a single bacterium, and they have used this technique to scan for new species in a biofilm [a group of microorganisms where cells stick to each other on a surface] isolated from a hospital sink. The results include the genome of a previously unrecognized phylum of bacteria, called TM6, that appears to be an obligate symbiote, perhaps living inside another cell found in the biofilm.

... This week, the group released a paper on a genome from a group of species called TM6. The name comes from “Torf, Mittlere Schicht,” which is “peat, middle layer” in German. That's the first case instance where the ribosomal RNA for this group of species had appeared but since then it's been found in a host of environmental samples: domestic water sources, acidic cave biofilms, acid mine drainage biofilms, wastewater biofilms, soil, contaminated groundwater and subsurface sites, aquatic moss, hypersaline mats, peat bogs, and peat swamps. The ribosomal RNA had suggested it was distantly related to all the bacterial groupings we knew about, and now the genome confirms it.

Perhaps the most striking thing about it is the fact that fully 43 percent of the genes appear to encode proteins that we've never seen before. Typically, due to a combination of common descent and gene transfer, many of the genes in new species are familiar. This one is so far out, most of them don't look like anything we know about. Which, of course, makes it hard to predict what they might do. [Ars Technica]

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