Environmental Sensory Perception by Oral Streptococci
Justin Merritt and Jens Kreth
from: Oral Microbial Ecology: Current Research and New Perspectives (Edited by: Nicholas S. Jakubovics and Robert J. Palmer Jr.). Caister Academic Press, U.K. (2013)
Oral streptococci encounter an exceptionally wide range of environmental stresses and population densities. These stimuli are sensed by efficient detection systems that also coordinate the appropriate adaptive genetic responses. The majority of these detection systems utilize membrane bound sensory proteins that are directly or indirectly regulated by their sensed stimuli. Such systems play an intimate role in mitigating the potential damage caused by changes in redox potential, fluctuations in local pH, and toxicity from antimicrobial agents. In addition, the typical life cycle of oral streptococci includes a transition from growth in a relatively low cell density planktonic state to an extremely high cell density biofilm environment. Consequently, various sensory systems are dedicated to detecting this increase in population density and regulating the genetic pathways that are essential for persistence in a highly competitive multispecies biofilm environment. Recent studies have identified many of the targets of these sensory systems and have provided unprecedented insight into the intimate connection between the constantly changing oral environment and the genetic machinery of oral bacteria read more ...