I

sosphaera pallida. Isosphaera pallida is a species within the phylum Planctomycetes. The Planctomycetes are unique in that while they don't have a true nucleus, typically their DNA is enclosed within a double membrane (though this feature seems to be absent in Isosphaera. I. pallida is phototactic*, reproduces by budding, and displays gliding motility. Unlike most eubacteria, I. pallida (and other Planctomycetes) lack muramic acid -- a key component of peptidoglycan -- in their cell wall. It is therefore believed that these organisms went on their merry evolutionary way before peptidoglycan was ever heard of.

*I. pallida moves towards light sources.