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.