It's a question we ask about many recently discovered bacteria: What, exactly, do the Verrucomicrobial do in the environment? Since their discovery, representatives of the phylum Verrucomicrobia have been detected in soil and aquatic environments around the world, but we have very few existing isolates to study in the lab. A study in mBio this week features a shotgun metagenomics approach to characterizing "Spartobacteria baltica", an abundant - but fluctuating - resident of the Baltic Sea. Clues in the reconstructed genome indicate the bacterium uses a set of pathways typical of many aerobic heterotrophic organisms, but there are also hints that it shares a close association with phytoplankton.
Samples from the Baltic Sea show that a single 16S phylotype of Spartobacteria (which, my research tells me, was not named for my alma mater's mascot http://goo.gl/vMKtl) is one of the dominating bacteria during the summer months. Using samples rich in this particular type, the team employed 454 pyrosequencing and assembled the ≥2kb contigs into a full genome of what they're calling "Spartobacteria baltica".
In addition to the usual metabolic suspects involved in heterptrophic metabolism, "Spartobacteria baltica" possesses 23 genes encoding glycoside hydrolases, enzymes that degrade polysaccharides. The genes represent 13 different glycoside hydrolase families, a hint that they can tackle a range of different substrates, including cellulose, mannan, xylan, chitin, and starch.
And where can an aquatic bacterium get a good supply of polysaccharides? From phytoplankton.
Click on the source link to read more on mBiosphere...