The present study and that of Fröls and coworkers [38]
demonstrate a propensity of haloarchaeal species to
form biofilms and indicate this may be a predominant
natural mode of growth for this group of organisms.
While haloarchaea are considered extremophiles, the
ability of any microbial group to form biofilms is consistent
with the emerging view that biofilm formation is
an adaptation common to most if not all species [16–19].
In this particular case, the benefits associated with a community
lifestyle match the environmental conditions thatchallenge microbial life in hypersaline environments. For
example, encapsulation within a hydrated nutrient-dense
ECM and a biofilm structure with areas that surround
developed microcolonies (Figure 1E-H), which likely
act as channels to facilitate waste and nutrient exchange,
may help explain the persistence of haloarchaeal
populations through prolonged periods of
starvation [73]. Overall, the delicate and motile nature
of multicellular structures imaged in static liquid
(Figure 1C-I and Figure 4) may reflect low levels of
natural circulation and water activity within hypersaline
environments and a selective advantage associated with
movement towards favorable conditions.