Harvard Medical School now recognized as players in widely used mechanisms Boston, Massachusetts 02115 for sensing cell numbers among gram-negative bacteria, the role of acylated HSLs as signal molecules was first discovered in the studies of the high cell density induc-Microbial Differentiation in Response tion of bioluminescence in the marine bacterium Vibrio to Starvation fischeri. The machi...

Bacteria communicate via small diffusible molecules to mediate group-coordinated behavior, a process designated as quorum sensing. The basic molecular quorum sensing system of Gram-negative bacteria consists of a LuxI-type autoinducer synthase producing acyl-homoserine lactones (AHLs) as signaling molecules, and a LuxR-type receptor detecting the AHLs to control expression of specific genes. Ho...

Figure 1: E. coli cells engineered with the luxI/luxR system and the microfluidic device setup in our experiments [4]. C6-HSL is a specific type of AHL. Quorum sensing is an essential communication mechanism in bacteria. By transmitting small molecules to each other, bacteria can sense their own population and respond accordingly. Coupling such mechanisms with synthetic biology can lead to a wi...

Abstract Background Intestinal dysbiosis is a key feature in the pathogenesis of inflammatory bowel diseases (IBD). Bacterial quorum sensing mediated by acyl-homoserine lactones (AHL) might play role dialogue between gut microbiota and host. The main objective our study was to investigate presence expression AHL synthase receptor genes human ecosystem during IBD. Methods To confirm gut, mass sp...

Numerous gram-negative bacterial pathogens regulate virulence factor expression by using a cell density mechanism termed quorum sensing (QS). An in silico analysis of the Burkholderia mallei ATCC 23344 genome revealed that it encodes at least two luxI and four luxR homologues. Using mass spectrometry, we showed that wild-type B. mallei produces the signaling molecules N-octanoyl-homoserine lact...

Bacterial pheromone signaling is often governed both by environmentally responsive regulators and by positive feedback. This regulatory combination has the potential to coordinate a group response among distinct subpopulations that perceive key environmental stimuli differently. We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedba...

BACKGROUND Quorum sensing (QS) networks are more commonly known as acyl homoserine lactone (HSL) networks. Recently, p-coumaroyl-HSL has been found in a photosynthetic bacterium. p-coumaroyl-HSL is derived from a lignin monomer, p-coumaric acid, rather than a fatty acyl group. The p-coumaroyl-HSL may serve an ecological role in diverse QS pathways between p-coumaroyl-HSL producing bacteria and ...

The luminescence (lux) operon (luxICDABEG) of the symbiotic bacterium Vibrio fischeri is regulated by the transcriptional activator LuxR and two acyl-homoserine lactone (acyl-HSL) autoinducers (the luxI-dependent 3-oxo-hexanoyl-HSL [3-oxo-C6-HSL] and the ainS-dependent octanoyl-HSL [C8-HSL]) in a population density-responsive manner called quorum sensing. To identify quorum-sensing-regulated (Q...