Abstract
Although biofilms are recognised as important in microbial colonisation, solutions to their inhibition are predominantly based on planktonic assays. These solutions have limited efficacy against biofilms. Here, a series of biofilm-orientated tests were used to identify anti-biofilm compounds from marine micro-flora. This led to the isolation of a complex of anti-biofilm compounds from an extract of Paenibacillus polymyxa (PPE). A combination of rpHPLC and mass spectrometry identified the principle components of PPE as fusaricidin B (LI-FO4b) and polymyxin D1, with minor contributions from surfactins. This complex (PPE) reduced the biofilm biomass of Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus bovis. In contrast, ampicillin was only effective against S. aureus. PPE also inhibited a self-assembling marine biofilm (SAMB) in co-incubation assays by 99.3% ± 1.9 and disrupted established SAMB by 72.4% ± 4.4, while ampicillin showed no significant reduction. The effectiveness of this complex of lipopeptides against single and multispecies biofilms suggests a future role in biofilm prevention strategies.
Acknowledgements
These studies were supported the by Higher Education Authority (Ireland) Technological Sector Research Programme Strand III: Core Research Strengths Enhancement, National Development Plan 2007-2013 (Grant No AI060753). The authors would like to express sincere thanks to James Dooley, S. Pereira, E.O Kane, E. McCauley, G. McKerr, A. M. Webba Da Silva and A.I. Karsisiotis for their technical assistance. The authors are also grateful to R. Heymans, G. Murthukrishnan and W. Brück for helpful discussions.