Development of an Escherichia coli biofilm platform for use in biocatalysis

Leech, James Thomas (2018). Development of an Escherichia coli biofilm platform for use in biocatalysis. University of Birmingham. Ph.D.

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Abstract

Biocatalysis processes use biologically-derived enzymes to perform fine-chemical synthesis. Whole-cell biocatalysis, using live microorganisms, offers protection against buffer conditions and denaturation, and allows turnover of effective enzymes. However, cells may still be damaged by reaction conditions. In nature, cell populations protect themselves by attaching to surfaces and producing a multi-component protective extracellular matrix. This multicellular mode of growth is termed a biofilm. Biofilms offer many advantages over individual free-floating cells which may be beneficial in whole-cell biocatalysis.
The primary aim of this work was to develop a biofilm platform using non-pathogenic Escherichia coli strains as a generic host for various biocatalysis enzymes. To this end, a simple, inexpensive and reliable biofilm generation method was developed and optimised using quantitative assays and confocal laser scanning microscopy. Reporter gene technology was used to provide insight into the expression of the matrix component curli. Flow cytometry was employed to reveal curli expression heterogeneity in biofilm-forming populations. Biofilm-modulating plasmids were used to determine whether improvements could be made to the biofilm-forming strains and their relevant effects were observed. Lastly, three biocatalysis processes were tested in the biofilm biocatalyst with observation of effects on biofilm formation, curli expression and biocatalytic potential.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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