Quorum Sensing Biosensors
Quorum sensing is a cell density-dependent phenomenon, which at high cell density induces expression of target genes in a bacterial population. In bacteria, quorum sensing is facilitated by cell-to-cell signaling molecules referred as autoinducers (AIs). Among Gram-negative bacteria, quorum sensing is mediated primarily by two classes of AIs: AI-1 and AI-2. Further, AI-1 has tens of subtypes and each bacterium responds to a very limited subtypes of AI-1. These signaling molecules, at high cell density, regulate several physiological processes among bacteria, including bioluminescence, biofilm, and virulence.
Numbers of bacteria harboring quorum-sensing system are increasing tremendously. During the last decade, several biosensors have been developed for the detection of AIs. Quorum-sensing biosensors have been proven fast and reliable first-line tools for the screening of bacterial species producing AIs. Some biosensors detect very specific type of AI, and some detect a range of AIs. Biosensors are used for both qualitative and quantitative detection of AIs. In this chapter, we describe different classes of biosensors available for the detection of AI-1 and AI-2. Different qualitative and quantitative methods for the detection of AIs and sensitivity and limitations of biosensors have also been discussed.
KeywordsQuorum Sense Quorum Sense System Acyl Homoserine Lactone Acyl Side Chain Quorum Sense Molecule
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