title: Investigation of extracellular polymeric substances (EPS) properties of P. aeruginosa and B. subtilis and their role in bacterial adhesion.
abstract: Extracellular polymeric substances (EPS) matrix in biofilm poses important functions such as a diffusion barrier to antimicrobial agents so that biofilm cells are more difficult to completely eliminate. Therefore, biofilm cells exhibit enhanced resilience unlike planktonic cells, and are more difficult to completely eliminate. In order to obtain a comprehensive understanding of bacterial adhesion to surfaces, knowledge of the composition and conformational properties of EPS produced during growth and biofilm formation is required, since their adhesive and conformational properties remain poorly understood at molecular level. Present study has provided further insights into identifying compositional and conformational properties of EPS produced by planktonic and biofilm cells of B. subtilis and P. aeruginosa. Various spectroscopy analyses showed that EPS produced by the two different species were chemically dissimilar. More proteinaceous compounds were present in EPS from B. subtilis, while EPS from P. aeruginosa were characterized by greater carbohydrate components. However, relative proportions of polysaccharides and/or proteins constituents varied with the growth mode of the bacteria. AFM was then used to probe the adhesive nature of EPS produced by the bacteria by using Single Molecule Force Spectroscopy (SMFS). Comparison of the two bacterial species indicated that the presence of polysaccharides promoted the adhesion strength of the EPS while proteins had lesser adherence effects. Comparison of the two growth modes for the same bacterial strain also indicated that greater EPS production and enhanced cellular adhesion are associated with biofilm growth.
authors.affiliation: Department of Chemical Engineering, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung, 40132, Indonesia. Electronic address: ardiyan@che.itb.ac.id.
authors.forename: Ardiyan
authors.initials: A
authors.lastname: Harimawan
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117576, Singapore.
authors.forename: Yen-Peng
authors.initials: YP
authors.lastname: Ting
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects*; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D005109:Extracellular Matrix / Q000737:chemistry* / Q000378:metabolism; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects*
chemical_list: D011108:Polymers; D011135:Polysaccharides, Bacterial
keywords: Adhesion force; B. subtilis; Biofilm; Extracellular polymeric substances; P. aeruginosa