Bioprinting of Engineered Biofilms for Microbial Electrosynthesis

Project Overview

Biofilms are surface-associated communities of interacting microbial populations and their associated secreted materials. Biofilms can be useful as biocatalysts, benefiting processes such as waste biodegradation or synthesis of biofuels and bioproducts. Microbiologists have investigated artificial biofilms for improved interfacing with the external environment and cell-cell communication, but these have generally lacked defined geometry or defined community structure. Existing methods for assembling or engineering biofilms are limited to controlling bacterial seeding density or media flow parameters. Here, we have developed a new microbial 3D-bioprinting technology, based on microprojection stereolithography, which directly enables the fabrication of high-complexity, well-defined artificial biofilms containing living bacterial.

Through utilization of this microbial 3D-bioprinting capability, we proceeded to develop photopolymerizable, biocompatible bioresins, including conductive bioresins designed to facilitate the growth of electrotrophic microbes. Our nanotube-based conductive bioresin was evaluated in terms of its polymerization kinetics, rheological properties, electron transport properties, and biocompatibility. Finally, we developed a novel microbial electrosynthesis system (MES) by leveraging these 3D-bioprinted living biocathodes in conjunction with Rhodopseudomonas palustris (R. palustris) a versatile electrotrophic bacteria. Our MES system was developed specifically as a method to directly enhance the efficiency of biomanufacturing polyhydroxybutyrate (PHB), a high-value, challenging-to-produce biodegradable plastic.

Mission Impact

The research conducted by our team directly supports the biosecurity mission at LLNL through the development of an environmentally-friendly and potentially highly scalable means to produce critical manufacturing materials via biomanufacturing. Printed microbes and the biochemical processes they are capable of represent a largely untapped potential to enhance our national bioresilience by providing alternative sources of a great variety of manufacturing and biomedical materials, as well as directly engineering platforms to examine and manipulate the behaviors of human-relevant bacterial microbiomes, natural and synthetic. We have developed a new, LLNL-specific, 3D-bioprinting technology for the direct manipulation of microbes for a wide range of possible applications, ranging from environmental decontamination to enhanced vaccine manufacture. This project has merged additive-manufacturing techniques with bioengineering to establish a new competency for the lab and has done so by driving innovation across two of the Lab's seven core competencies: bioscience and bioengineering and advanced materials and manufacturing.

Publications, Presentations, and Patents

Hynes, William. "LLNL Enabling Technologies for Microbiome Study." Presentation - DOE/NASA Interchange Meeting. March 2022.

Moya, Monica. "LLNL's Boprinting and Advanced Fabrication Techniques." Invited talk at UC Davis, Davis, CA. January 2021.

Hynes, William. "Additively Manufactured Architected Synthetic Biofilms." MRS Conference. Deccmber 2020.