PolyBact · Identifying Chemical Cues in the Polymer-Mediated Engineering of Microorganisms

Identifying Chemical Cues in the Polymer-Mediated Engineering of Microorganisms

Understanding and controlling the interaction of polymers and microorganisms such as bacteria is of critical importance because the binding of microorganisms to polymers and surfaces has major consequences in healthcare, biotechnology and industry. On one hand, we need to understand how to inhibit adhesion and thus prevent unwanted fouling of surfaces, which results in infection, or in damage to industrial equipment. On the other hand, biofilms provide a unique platform for biocatalysis, where bacteria make chemicals for a variety of purposes. This way the toughness and resistance of biofilms to external damage is exploited to prepare high end value products. An underlying limitation that is compromising the development of polymers for these applications, is our lack of understanding of how these materials are affecting microbial physiology. Whilst we have a basic understanding of what chemistries need to be used for each application, for example to induce cell death, or inhibit the adhesion to host or surfaces, little is known about how bacteria respond and adapt to the presence of these polymers: we do not know how complex chemical and physical cues affect downstream cellular signalling following interaction with these materials, to affect phenotypical changes such as biofilm production or virulence factor expression. As a consequence, many candidate polymers are not translated to application because eventually they do not induce the expected effect. Therefore, the overall objectives of the project was to identify the roles of different types of polymer-bacteria interactions in bacterial behaviour. To this end, we synthesized a series of polymers bearing different functionalities and, using Vibrio cholerae as a model organism, explored the responses of bacteria to these nanomaterials. We discovered that cationic and hydrophobic functionalities were able to induce formation of cell clusters whereas polymers containing sugars demonstrated only short-lived interaction with cells and did not form stable clusters. Then we found that cationic polymers with high charge density and hydrophobic polymers induced biofilm formation, this effect was dependent on pH and polymer concentration. A decrease in biofilm production was observed only for polymers showing high cytotoxicity. At the same time, none of the tested polymers had significant effect on cholera toxin production.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз