Biofilms provide the physical organization and proximity
necessary to facilitate cooperative functions among species.
The formation and maintenance of biofilms is an area of
intense interest in fields of medicinal, agricultural, industrial
and environmental microbiology. Microbial communication
is believed to be a critical feature of biofilm function.
Kjelleberg and Molin (pp 254–258) offer a critical look at the
role of quorum sensing in the function of microbial biofilms,
but caution against concluding that quorum sensing is either
a central or unique means of communication in biofilms
because of the difficulties in isolating variables and seeing a
biofilm from the perspective of its members. Leveau and
Lindow (pp 259–265) address the problem of seeing the
world from the perspective of a microorganism. To meet this
challenge, they introduce the powerful technology of biosensors,
which are reporter gene systems that quantitatively
sense concentrations of metals, nutrients, or ions and degrees
of physical parameters as a bacterium senses them. A bioreporter
transduces the signal that the bacterium would
receive, making it perceptible to the human observer without
requiring the signal itself to be amplified and therefore
skewed from the signal perceived in the natural system. Few
tools of microbiology provide such precise snapshots of the
conditions in a community because few can take measurements
with as little disturbance of the community.