Industrial Waste based Bio-manufacturing of Synthetic Tandem Repeat
Protein Fibers
Abstract
Protein-based fibers are lightweight, biodegradable, have excellent
moisture and temperature regulation, and exceptional mechanical
properties, but they are limited in production capacity. Biosynthetic
protein-based fibers have the potential to overcome these concerns, but
large-scale production with high yield (>1g/L) and purity
(>%80), as well as low cost (<$50/kg), must be
achieved. Here we developed an optimized expression and purification
method for biosynthetic tandem repeat proteins, that are inspired from
squid ring tooth (SRT) protein using three wet-waste feedstock, corn
steep liquor, molasses, and soybean extract. SRT is composed of a highly
stiff, naturally occurring bioplastic and these properties arise from
the molecular architecture of the constituant proteins, which are
segmented co-polymers with alternating semicrystalline and amorphous
domains similar to silk. We have developed protocols to use liquid
industrial and agricultural waste as feedstock for SRT production, which
has the potential to divert waste streams into useful products. We also
show that our biosynthetic protein powder, produced at 1 g/L yield and
greater than 80% purity, can be manufactured into fibers using
conventional split film or wet-spinning approaches.