Extracellular DNA in Single- and Multiple-Species Unsaturated Biofilms

Abstract

Microb. Ecol. 43:416-423, 2002).Here, we investigated the compositional similarity of eDNA to cellular DNA, the relative quantity of eDNA, and the terminal restriction fragment length polymorphism (TRFLP) community profile of eDNA in multiplespecies biofilms. By randomly amplified polymorphic DNA analysis, cellular DNA and eDNA appear identical for P. aeruginosa biofilms. Significantly more eDNA was produced in P. aeruginosa and Pseudomonas putida biofilms than in Rhodococcus erythropolis or Variovorax paradoxus biofilms. While the amount of eDNA in dual-species biofilms was of the same order of magnitude as that of of single-species biofilms, the amounts were not predictable from single-strain measurements. By the Shannon diversity index and principle components analysis of TRFLP profiles generated from 16S rRNA genes, eDNA of four-species biofilms differed significantly from either cellular or total DNA of the same biofilm. However, total DNA-and cellular DNA-based TRFLP analyses of this biofilm community yielded identical results. We conclude that extracellular DNA production in unsaturated biofilms is species dependent and that the phylogenetic information contained in this DNA pool is quantifiable and distinct from either total or cellular DNA.

The cidA murein hydrolase regulator contributes to DNA release and biofilm development in Staphylococcus aureus

“…44). Several studies have shown that eDNA is an abundant component of the extracellular matrix of P. aeruginosa biofilm (34,35,45). DNase treatment has been shown to disrupt P. aeruginosa biofilm grown in vitro (35,46) and is used in combination with antibiotics to treat P. aeruginosa infections of cystic fibrosis patients (47).…”

Phage-induced lysis enhances biofilm formation in Shewanella oneidensis MR-1

“…In contrast, the significance of eDNA for cellular attachment and structural integrity has more recently been recognized for an increasing number of Gram-negative and Grampositive species (Whitchurch et al, 2002;Steinberger and Holden, 2005;Allesen-Holm et al, 2006;Moscoso et al, 2006;Jurcisek and Bakaletz, 2007;Qin et al, 2007;Izano et al, 2008;Thomas et al, 2008;Heijstra et al, 2009;Vilain et al, 2009;Harmsen et al, 2010;Lappann et al, 2010). Release of DNA in bacterial biofilms has mainly been attributed to the lysis of a cellular subpopulation, mediated by the activity of autolysis systems (Allesen-Holm et al, 2006;Rice et al, 2007;Thomas et al, 2008Thomas et al, , 2009Mann et al, 2009).…”

Sticky Situations: Key Components That Control Bacterial Surface Attachment

“…Whitchurch et al (166) first demonstrated that P. aeruginosa PAO1 biofilm formation was significantly reduced under flowing conditions in the presence of DNase. eDNA has been subsequently shown to contribute to biofilm formation by clinical P. aeruginosa isolates as well as by a variety of bacterial species, including Staphylococcus epidermidis, through analyses of biofilm formation by lysis-defective mutants and of DNA removal from the biofilm matrix (67,117,133,146,150). The contribution of eDNA to attachment and biofilm formation, however, appears to be temporal: experiments utilizing DNase I have suggested that cells in young PAO1 biofilms are held together by eDNA, whereas the cells in more-mature PAO1 biofilms are held together primarily by components other than eDNA (98,166).…”