A crewed mission to and from Mars may include an exciting array of enabling biotechnologies that leverage inherent mass, power, and volume advantages over traditional abiotic approaches. In this perspective, we articulate the scientific and engineering goals and constraints, along with example systems, that guide the design of a surface biomanufactory. Extending past arguments for exploiting stand-alone elements of biology, we argue for an integrated biomanufacturing plant replete with modules for microbial in situ resource utilization, production, and recycling of food, pharmaceuticals, and biomaterials required for sustaining future intrepid astronauts. We also discuss aspirational technology trends in each of these target areas in the context of human and robotic exploration missions.

Providing life-support materials to crewed space exploration missions is pivotal for mission success. However, as missions become more distant and extensive, obtaining these materials from in situ resource utilization is paramount. The combination of microorganisms with electrochemical technologies offers a platform for the production of critical chemicals and materials from CO2 and H2O, two compounds accessible on a target destination like Mars. One such potential commodity is poly(3-hydroxybutyrate) (PHB), a common biopolyester targeted for additive manufacturing of durable goods. Here, we present an integrated two-module process for the production of PHB from CO2. An autotrophic Sporomusa ovata (S. ovata) process converts CO2 to acetate which is then directly used as the primary carbon source for aerobic PHB production by Cupriavidus basilensis (C. basilensis). The S. ovata uses H2 as a reducing equivalent to be generated through electrocatalytic solar-driven H2O reduction. Conserving and recycling media components is critical, therefore we have designed and optimized our process to require no purification or filtering of the cell culture media between microbial production steps which could result in up to 98% weight savings. By inspecting cell population dynamics during culturing we determined that C. basilensis suitably proliferates in the presence of inactive S. ovata. During the bioprocess 10.4 mmol acetate L –1 day–1 were generated from CO2 by S. ovata in the optimized media. Subsequently, 12.54 mg PHB L–1 hour–1 were produced by C. basilensis in the unprocessed media with an overall carbon yield of 11.06% from acetate. In order to illustrate a pathway to increase overall productivity and enable scaling of our bench-top process, we developed a model indicating key process parameters to optimize.

SILAR-deposited, Ti-doped hematite films with FeOOH overlayer collect nearly all charges generated within a diffusion length of the depletion region.

Mediated microbial electrosynthesis (MES) represents a promising strategy for the capture and conversion of CO2 into carbon‐based products. We describe the development and application of a comprehensive multiphysics model to analyze a formate‐mediated MES reactor. The model shows that this system can achieve a biomass productivity of ∼1.7 g L−1 h−1 but is limited by a competitive trade‐off between O2 gas/liquid mass transfer and CO2 transport to the cathode. Synthetic metabolic strategies are evaluated for formatotrophic growth, which can enable an energy efficiency of ∼21 %, a 30 % improvement over the Calvin cycle. However, carbon utilization efficiency is only ∼10 % in the best cases due to a futile CO2 cycle, so gas recycling will be necessary for greater efficiency. Finally, separating electrochemical and microbial processes into separate reactors enables a higher biomass productivity of ∼2.4 g L−1 h−1. The mediated MES model and analysis presented here can guide process design for conversion of CO2 into renewable chemical feedstocks.

A crewed mission to and from Mars may include an exciting array of enabling biotechnologies that leverage inherent mass, power, and volume advantages over traditional abiotic approaches. In this perspective, we articulate the scientific and engineering goals and constraints, along with example systems, that guide the design of a surface biomanufactory. Extending past arguments for exploiting stand-alone elements of biology, we argue for an integrated biomanufacturing plant replete with modules for microbial \textit{in situ} resource utilization, production, and recycling of food, pharmaceuticals, and biomaterials required for sustaining future intrepid astronauts. We also discuss aspirational technology trends in each of these target areas in the context of human and robotic exploration missions in the coming century.

Hematite (α-Fe 2 O 3 ) has been widely investigated for photoelectrochemical (PEC) water splitting, but questions remain regarding the nature of improvements induced by different dopants. We report on facile annealing treatments to dope hematite with Ti and Sn, and we provide insight into the effects of the dopant concentration profiles on two key steps of PEC water oxidation: charge separation and interfacial hole transfer. Hematite thin films were deposited by successive ionic layer adsorption and reaction (SILAR), with and without the presence of a TiO 2 underlayer on the F:SnO 2 substrate, and annealed to drive diffusion of Ti and Sn from the underlying layers into the hematite. PEC measurements showed that Ti and Sn at the hematite surface increase hole injection efficiency from nearly zero to above 80%. Ti and Sn also slightly improve charge separation efficiency, although separation efficiency remains below 20% due to low hole mobility and high recombination rate. To overcome the small hole transport length, extremely thin hematite coatings were deposited on Sb:SnO 2 monolayer inverse opal scaffolds. Photocurrent increased proportionately to the surface area of the scaffold. This study provides insight into the use of dopants and nanostructured architectures to improve PEC performance of hematite photoanodes.

Electromicrobial production (EMP) processes, in which electricity or electrochemically-derived mediator molecules serve as energy sources to drive biochemical processes, represent an attractive strategy for the conversion of CO2 into carbon-based...

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