High level biosynthesis of a silk-elastin-like protein in E. coli

Abstract

Silk-elastin-like proteins (SELPs) have enormous potential for use as customizable biomaterials in numerous biomedical and materials applications yet success in harnessing this potential has been limited by the lack of a commercially viable industrially relevant production process. We have developed a scalable fed-batch production approach which enables a SELP volumetric productivity of 4.3 g L-1 with E. coli BL21(DE3). This is the highest SELP productivity reported to date and is 50-fold higher than that reported by other groups. As compared to typical fed-batch processes, high pre-induction growth rates and low inducer and oxygen concentrations are allowed whereas reduced post-induction feeding rates are preferred. Limiting factors were identified and productivity was found to be strongly influenced by a trade-off between the rate of production and plasmid stability. The process developed is robust, reproducible and applicable to scale up to the industrial level and moves these biopolymers a step closer to the marketplace.