Search for: All records

Abstract The field of hybrid engineered living materials seeks to pair living organisms with synthetic materials to generate biocomposite materials with augmented function since living systems can provide highly-programmable and complex behavior. Engineered living materials have typically been fabricated using techniques in benign aqueous environments, limiting their application. In this work, biocomposite fabrication is demonstrated in which spores from polymer-degrading bacteria are incorporated into a thermoplastic polyurethane using high-temperature melt extrusion. Bacteria are engineered using adaptive laboratory evolution to improve their heat tolerance to ensure nearly complete cell survivability during manufacturing at 135 °C. Furthermore, the overall tensile properties of spore-filled thermoplastic polyurethanes are substantially improved, resulting in a significant improvement in toughness. The biocomposites facilitate disintegration in compost in the absence of a microbe-rich environment. Finally, embedded spores demonstrate a rationally programmed function, expressing green fluorescent protein. This research provides a scalable method to fabricate advanced biocomposite materials in industrially-compatible processes. 

Abstract Although enzymes are efficient catalysts capable of converting various substrates into desired products with high specificity under mild conditions, their effectiveness as catalysts is substantially reduced when substrates are poorly water-soluble. In this study, to expedite the enzymatic conversion of a hydrophobic substrate, we use a bicontinuous interfacially jammed emulsion gel (bijel) which provides large interfacial area between two immiscible liquids: oil and water. Using lipase-catalyzed hydrolysis of tributyrin as a model reaction in a batch mode, we show that bijels can be used as media to enable enzymatic reaction. The bijel system gives a four-fold increase in the initial reaction rate in comparison to a stirred biphasic medium. Our results demonstrate that bijels are powerful biphasic reaction media to accelerate enzymatic reactions with various hydrophobic reagents. This work also demonstrates that bijels can potentially be used as reaction media to enable continuous reactive separations.