Here's a tree showing the relationship between GFAJ-1 and its closest known relatives (source).
And here's a link to a paper describing VERY THOROUGH phenotypic characterization of all the formally described species of Halomonas: Mata et al., 2002. A detailed phenotypic characterization of the type strains of Halomonas species. System. Appl. Microbiol. 25:360-375. I was initially assuming that GFAJ-1 would be quite picky about growth conditions, but if it's a typical Halomonas species it's probably quite robust, as they all tolerate wide ranges of salt concentration, pH and temperature.
Regarding that figure, I am one of the wikipedia editors for the English version of GFAJ-1 and I though it may be of interest to mention that the other editors and I had a behind the scene discussion on what to state on the page due to the "information [being] incorrect by omission". Doing some background research it was clear that
ReplyDelete— GFAJ-1 is definitely a Halomonas sp.
— the 16S sequence is over 99% similar to stain GTW (paper)
— the fact this group of strain does not have an official standing is because nobody has cared to officially describe them, not because they are distant/ancient Halomonaceae (as the paper hints)