Introducing Porosity in Colloidal Biocoatings to Increase Bacterial Viability.

Introducing Porosity in Colloidal Biocoatings to Increase Bacterial Viability. Biomacromolecules. 2020 Jun 25;: Authors: Chen Y, Krings S, Booth JR, Bon SAF, Hingley-Wilson S, Keddie JL Abstract A biocoating confines non-growing, metabolically-active bacteria within a synthetic colloidal polymer (i.e. latex) film. Bacteria encapsulated inside biocoatings can perform useful functions, such as a biocatalyst in wastewater treatment. A biocoating needs to have high a permeability to allow a high rate of mass transfer for rehydration and the transport of both nutrients and metabolic products. It therefore requires an interconnected porous structure. Tuning the porosity architecture is a challenge. Here, we exploited rigid tubular nanoclays (halloysite) and non-toxic latex particles (with a relatively high glass transition temperature) as the colloidal "building blocks" to tailor the porosity inside biocoatings containing Escherichia coli bacteria as a model organism. Electron microscope images revealed inefficient packing of the rigid nanotubes and proved the existence of nanovoids along the halloysite/polymer interfaces. Single-cell observations using confocal laser scanning microscopy provided evidence for metabolic activity of the E. coli within the biocoatings through the expression of yellow fluorescent protein. A custom-built apparatus was used to measure the permeability of a fluorescein sodium salt in the biocoatings. Whereas ther...
Source: Biomacromolecules - Category: Biochemistry Authors: Tags: Biomacromolecules Source Type: research