Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Polymer and Fiber Science


Ellison, Michael S


Advancements in the field of biomaterials are being made to produce an artificial silk fiber. A gene was constructed which utilized components from both the dragline silk of Nephila clavipes and nematode collagen. For this engineered protein, the yeast strain Pichia pastoris was chosen to be the host organism. Previous research has shown P. pastoris to have comparatively low amounts of specific protein productivity. Therefore, this problem must be compensated for by obtaining extremely high cell densities. The main focus of this study was to optimize the fermentation parameters of transgenic yeast cultures within a bioreactor in order to increase the yield of the recombinant protein. Through media improvement and feed pump control, cell densities of 350 optical density (OD) were obtained. Concentration and purification methods revealed insight into this material's potential for future processing. Additionally, comparative studies with natural spider silk revealed temperature fluctuations within the spinneret region.