title: Inhibition of biofilm formation by D-tyrosine: Effect of bacterial type and D-tyrosine concentration.
abstract: D-Tyrosine inhibits formation and triggers disassembly of bacterial biofilm and has been proposed for biofouling control applications. This study probes the impact of D-tyrosine in different biofilm formation stages in both G+ and G- bacteria, and reveals a non-monotonic correlation between D-tyrosine concentration and biofilm inhibition effect. In the attachment stage, cell adhesion was studied in a flow chamber, where D-tyrosine caused significant reduction in cell attachment. Biofilms formed by Pseudomonas aeruginosa and Bacillus subtilis were characterized by confocal laser scanning microscopy as well as quantitative analysis of cellular biomass and extracellular polymeric substances. D-Tyrosine exhibited strong inhibitive effects on both biofilms with an effective concentration as low as 5 nM; the biofilms responded to D-tyrosine concentration change in a non-monotonic, bi-modal pattern. In addition, D-tyrosine showed notable and different impact on EPS production by G+ and G- bacteria. Extracellular protein was decreased in P. aeruginosa biofilms, but increased in those of B. subtilis. Exopolysaccharides production by P. aeruginosa was increased at low concentrations and reduced at high concentrations while no impact was found in B. subtilis. These results suggest that distinct mechanisms are at play at different D-tyrosine concentrations and they may be species specific. Dosage of D-tyrosine must be carefully controlled for biofouling control applications.
authors: Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, United States.
authors: Cong
authors: C
authors: Yu
authors: Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, United States.
authors: Xuening
authors: X
authors: Li
authors: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors: Nan
authors: N
authors: Zhang
authors: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors: Donghui
authors: D
authors: Wen
authors: Scientific and Laboratory Services, Pall Corporation, 25 Harbor Park Dr., Port Washington, NY 11050, United States.
authors: Charles
authors: C
authors: Liu
authors: Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, United States; Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX 77005, United States; Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, United States; NSF Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment, Rice University, Houston, TX 77005, United States; The Smalley-Curl Institute, Rice University, Houston, TX 77005, United States. Electronic address: qilin.li@rice.edu.
authors: Qilin
authors: Q
authors: Li
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000032:analysis; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D018533:Biomass; D021621:Imaging, Three-Dimensional; D011135:Polysaccharides, Bacterial / Q000032:analysis; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D014443:Tyrosine / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial; D014443:Tyrosine
keywords: Biofilm; Biofouling; Extracellular polymeric substances; d-Amino acids; d-Tyrosine