Optimizing Silk Protein Production Using an Engineering Approach

Abstract

The acquisition of spider silk is a complex and costly process that restricts its availability. Increasing applications stemming from the biomedical and pharmaceutical sectors is driving the demand higher, necessitating the need for efficient large-scale production. This thesis investigates 1) recombinant protein expression systems, 2) major ampullate gland cell culture techniques for natural silk production, and 3) process optimization of recombinant silk protein expression. Using a process engineering analysis, the current E.coli system expression system was found to be a cost-effective and efficient technique for silk production. While a Box-Behnken predictive model was developed to optimize expression conditions based on small-scale E.coli expression data, it failed to translate to a larger-scale. Alternatively, the protein secreting cells that line the major ampullate silk gland were isolated and grown in conditions mimicking the native microenvironment, demonstrating a clear impact on growth of the cells and a potential new source of silk.