Related Experiment Video

Updated: May 15, 2026

Microtiter Dish Biofilm Formation Assay
03:57

Microtiter Dish Biofilm Formation Assay

Published on: January 30, 2011

Tryptophan inhibits biofilm formation by Pseudomonas aeruginosa

Kenneth S Brandenburg1, Karien J Rodriguez, Jonathan F McAnulty

  • 1Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.

Antimicrobial Agents and Chemotherapy
|January 16, 2013
PubMed

Insights

Tryptophan, particularly a mix of its d and l forms, effectively inhibits Pseudomonas aeruginosa biofilm formation. This amino acid also disrupts existing biofilms and enhances bacterial motility, offering potential therapeutic strategies for chronic wounds.

Area of Science:

  • Microbiology
  • Biochemistry
  • Wound Healing Research

Background:

  • Pseudomonas aeruginosa biofilms are a significant factor in chronic wound infections.
  • Understanding mechanisms to control biofilm formation is crucial for effective wound treatment.

Purpose of the Study:

  • To investigate the effect of d- and l-tryptophan isoforms on Pseudomonas aeruginosa biofilm formation.
  • To determine if tryptophan can disrupt pre-existing biofilms and influence bacterial motility.

Main Methods:

  • Utilized tissue culture plates to assess biofilm inhibition by tryptophan.
  • Examined the impact of d-/l-tryptophan on established biofilms.
  • Measured changes in Pseudomonas aeruginosa swimming motility in the presence of tryptophan.

Main Results:

  • Both d- and l-tryptophan isoforms inhibited Pseudomonas aeruginosa biofilm formation.
  • An equimolar ratio of d-/l-tryptophan demonstrated the most significant inhibition.
  • Tryptophan addition led to partial disassembly of existing biofilms and increased bacterial swimming motility.

Conclusions:

  • Tryptophan isoforms, especially in combination, are potent inhibitors of Pseudomonas aeruginosa biofilm development.
  • Tryptophan's ability to disrupt biofilms and enhance motility suggests therapeutic potential for chronic wound management.

More Related Videos

Visualizing the Effects of Sputum on Biofilm Development Using a Chambered Coverglass Model05:03

Visualizing the Effects of Sputum on Biofilm Development Using a Chambered Coverglass Model

Published on: December 14, 2016

Quantifying the Effects of Antimicrobials on In vitro Biofilm Architecture using COMSTAT Software06:18

Quantifying the Effects of Antimicrobials on In vitro Biofilm Architecture using COMSTAT Software

Published on: December 14, 2020

Related Concept Videos

Biofilms01:29

Biofilms

Biofilms are complex communities of microorganisms encased in a self-produced extracellular polysaccharide matrix attached to surfaces. These microbial consortia can include single or multiple species, providing enhanced survival benefits by forming organized, multilayered structures.The formation of biofilms occurs through four key stages: attachment, colonization, development, and dispersal.During attachment, free-swimming planktonic cells adhere to a surface, often facilitated by...
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Transcription Attenuation in Prokaryotes02:42

Transcription Attenuation in Prokaryotes

Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure.  Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
Repressible Operon: trp Operon01:21

Repressible Operon: trp Operon

The trp operon in Escherichia coli exemplifies a repressible operon. It regulates the synthesis of tryptophan through repressor-mediated transcriptional control and attenuation. This dual regulatory mechanism ensures tryptophan biosynthesis occurs only when needed, conserving cellular resources.Structure of the trp OperonThe trp operon consists of five structural genes (trpE, trpD, trpC, trpB, and trpA) that encode enzymes for tryptophan biosynthesis. These genes are transcribed as a single...
Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
Inhibitors of Bacterial DNA Synthesis01:28

Inhibitors of Bacterial DNA Synthesis

Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...