  Chemical surfactants are omnipresent in consumers' products but they suffer
from environmental concerns. For this reason, complete replacement of
petrochemical surfactants by biosurfactants constitute a holy grail but this is
far from occurring any soon. If the "biosurfactants revolution" has not
occurred, yet, mainly due to the higher cost and lower availability of
biosurfactants, another reason explains this fact: the poor knowledge of their
properties in solution. This tutorial review aims at reviewing the
self-assembly properties and phase behavior, experimental (sections 2.3 and
2.4) and from molecular modelling (section 5), in water of the most important
microbial biosurfactants (sophorolipids, rhamnolipids, surfacting,
cellobioselipids, glucolipids) as well as their major derivatives. A critical
discussion of such properties in light of the well-known packing parameter of
surfactants is also provided (section 2.5). The relationship between the
nanoscale self-assembly and macroscopic materials properties, including
hydrogelling, solid foaming, templating or encapsulation is specifically
discussed (section 2.7). We also present their self-assembly and adsorption at
flat and complex air/liquid (e.g., foams), air/solid (adhesion), liquid/solid
(nanoparticles) and liquid/liquid (e.g., emulsions) interfaces (section 3). A
critical discussion on the use of biosurfactants as capping agents for the
development of stable nanoparticles is specifically provided (section 3.2.4).
Finally, we discuss the major findings involving biosurfactants and
macromolecules, including proteins, enzymes, polymers and polyelectrolytes.
