As seawater freezes into sea ice, all of the dissolved constituents of the water become concentrated within the solid ice matrix that forms. Because it is more dense than seawater due to the high salt content, a lot of this ‘brine’ will drain from the ice by gravity. However, some brine remains in the ice [...]

One way to assess the microbial community structure in an environment is to use a ‘fingerprinting’ technique, like T-RFLP or ARISA, to interrogate the ’species’ living there as determined from their 16S rRNA genes or some functional gene like amoA. Here’s an example of a T-RFLP electropherogram from sea ice:

You can see that most of [...]

We use optical density (OD) at a wavelength of 600nm as a quick approximation of cell abundance in liquid bacterial culture in lieu of counting the cells on a microscope. Different bacterial strains can have different relationships between OD and cell abundance depending on the amounts of polysaccharides or other secondary metabolites they might [...]