Role of polyamines in biofilm - based water decontamination

Abstract

Over the years, there has been a steady increase of biofilm based applications but still the proper understanding of biofilms remain relatively poor. Despite knowing the components and structures in biofilms, proper understanding of the interaction between components are still largely unknown. This study sought to ascertain the impact of polyamines on biofilms by contacting S. oneidensis MR-1 WT and its deletion mutants speA, speD and speAD with putrescine and spermidine. Recent studies have reported that the presence of putrescine and spermidine inhibit the growth of biofilms while another study suggested that spermidine in concentrations not more than 200 μM promoted biofilm formation. In our study, the results obtained confirmed that the presence of putrescine and spermidine did indeed inhibit biofilm formation. However, this finding was only valid in mutants that were able to produce their own putrescine and spermidine. The mutants which had a putrescine or spermidine biosynthesis pathway disrupted were found to have formed more robust biofilms instead with the addition of putrescine and spermidine. It is also hypothesized from the results that the gene speA is a major pathway in polyamine synthesis, without which the entire biofilm formation would be significantly affected. It can be concluded that putrescine and spermidine in adequate concentrations is essential for robust biofilm formation should thus be further studied upon for future technological advances.