Meh.
They're talking about introns an exons, the regions of DNA that are presumed to be "spacers" or "junk" and the parts that actually code for proteins the cell uses to build it's structures and carry out functions.
The general rule of thumb, the more complex and higher the organism on the "tree of life" etc. the more introns it'll have spacing out the exons that actually "do something". This is believed to be because the further the organism has mutated, evolved, and specialized away from basic single celled life, the more leftover or cast-off genes wind up as spacers/fillers or introns.
But as noted, it's just a rule of thumb. There's mounting evidence that introns do 'do stuff' to control or organize certian biological functions, they might code for other things, or even the length or spacing of introns might be a secondary meta-code in DNA. It's highly unlikely you'd get a viable organism if you took say a mouse genome, or a human's and edited away all the introns, leaving just the exons.
For such a simple bacterium to have a large portion of it's DNA/genome full of introns is really unusual, but it's obviously what's "normal" for this particular ocean bacterium. And bacteria have the ability to swap or steal genes from each other, (Horizontal gene transfer) even across species lines, something higher multi-cellular organisms generally can't do, or at least do much much less often.
So it's possible this particular bacterium got it's DNA all goobered up in some bad trades, and it didn't kill it, it survived, filled an ecological niche fixing nitrogen in seawater. The excess (over what's expected) of introns may have nothing to do with the bacteria's success as one of the most prolific ocean organisms.
Honestly, if we set up some sort of huge automated laboratory ship that did nothing but filter seawater at different depths for all the single-cell organisms it could find, and sequence the DNA of all of them, we'd find all sorts of crazy stuff that breaks all of "the rules" and made science re-work major chunks of it's biological theories every few days, maybe every few hours. But at the same time, it's not surprising, because the single-celled life and the oceans, it's like a massive random blind supercomputer churning out every possible combination through mutation, HGT (
http://en.wikipedia.org/wiki/Horizontal_gene_transfer ) and natural selection.
