Applications of biosurfactants and iron chelating agents to inhibit bacterial adhesion on dental materials

• Grant number: 12/14326-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2012
• Effective date (End): December 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Augusto Etchegaray Júnior
• Grantee: Cristina Silva da Silva
• Host Institution: Faculdade de Química. Pontifícia Universidade Católica de Campinas (PUC-CAMP). Campinas , SP, Brazil

Abstract

In the oral environment, the formation of microbial biofilm and the frequent ingestion of sucrose are two factors that can contribute to establishment of dental caries, since they promote the development of pathogenic species such as Streptococcus mutans. Biofilm can be removed by mechanical methods, thus tooth brushing and flossing. However, in some cases it is necessary to use chemical agents with low antimicrobial activity but the ability to remove dental plaque and/or prevent its development. Among these agents we can cite surfactants that could inhibit bacterial adhesion to enamel. Following this rational, biosurfactants can be produced by growing the producing microbes such as Bacillus subtilis, which produces a number of non-ribosomal peptides, including the surfactin, iturin and fengycin families. Among these, the surfactin family has more appropriate properties, high surfactant activity and moderate antimicrobial activity, important characteristics for the oral environment considering the need to keep the non pathogenic microbial population. Considering that bacterial fixation on enamel surface is one of the initial processes for biofilm formation and knowing that for biofilm maturation it is important the synthesis of extracellular polymeric substances (EPS), an enzymatic process that can be induced by iron, it is possible that the use of iron chelating agents will also disturb the biofilm by inhibiting its maturation. Therefore, the aim of this project is to explore two avenues to inhibit or disturb biofilm assembly: (i) inhibit bacterial adhesion on hard surfaces such as polystyrene microtiter plates and/or dental material; (ii) evaluate the potentialities for the use of siderophores to inhibit EPS synthesis. Considering the similarities between biofilms and biofouling, it is expected that the results may also contribute for the development of methods to prevent biofouling in pipes, constructing material and/or filtration membranes used in water treatment. (AU)