Microbial biomanufacturing for space-exploration-what to take and when to make.

As renewed interest in human space-exploration intensifies, a coherent and modernized strategy for mission design and planning has become increasingly crucial. Biotechnology has emerged as a promising approach to increase resilience, flexibility, and efficiency of missions, by virtue of its ability to effectively utilize in situ resources and reclaim resources from waste streams. Here we outline four primary mission-classes on Moon and Mars that drive a staged and accretive biomanufacturing strategy. Each class requires a unique approach to integrate biomanufacturing into the existing mission-architecture and so faces unique challenges in technology development. These challenges stem directly from the resources available in a given mission-class-the degree to which feedstocks are derived from cargo and in situ resources-and the degree to which loop-closure is necessary. As mission duration and distance from Earth increase, the benefits of specialized, sustainable biomanufacturing processes also increase. Consequentially, we define specific design-scenarios and quantify the usefulness of in-space biomanufacturing, to guide techno-economics of space-missions. Especially materials emerged as a potentially pivotal target for biomanufacturing with large impact on up-mass cost. Subsequently, we outline the processes needed for development, testing, and deployment of requisite technologies. As space-related technology development often does, these advancements are likely to have profound implications for the creation of a resilient circular bioeconomy on Earth.

The Hunt for Ancient Prions: Archaeal Prion-Like Domains Form Amyloid-Based Epigenetic Elements.

Prions, proteins that can convert between structurally and functionally distinct states and serve as non-Mendelian mechanisms of inheritance, were initially discovered and only known in eukaryotes, and consequently considered to likely be a relatively late evolutionary acquisition. However, the recent discovery of prions in bacteria and viruses has intimated a potentially more ancient evolutionary origin. Here, we provide evidence that prion-forming domains exist in the domain archaea, the last domain of life left unexplored with regard to prions. We searched for archaeal candidate prion-forming protein sequences computationally, described their taxonomic distribution and phylogeny, and analyzed their associated functional annotations. Using biophysical in vitro assays, cell-based and microscopic approaches, and dye-binding analyses, we tested select candidate prion-forming domains for prionogenic characteristics. Out of the 16 tested, eight formed amyloids, and six acted as protein-based elements of information transfer driving non-Mendelian patterns of inheritance. We also identified short peptides from our archaeal prion candidates that can form amyloid fibrils independently. Lastly, candidates that tested positively in our assays had significantly higher tyrosine and phenylalanine content than candidates that tested negatively, an observation that may help future archaeal prion predictions. Taken together, our discovery of functional prion-forming domains in archaea provides evidence that multiple archaeal proteins are capable of acting as prions-thus expanding our knowledge of this epigenetic phenomenon to the third and final domain of life and bolstering the possibility that they were present at the time of the last universal common ancestor.

A Makerspace for Life Support Systems in Space.

Human space exploration and settlement will require leaps forward in life support for environmental management and healthcare. Life support systems must efficiently use nonrenewable resources packed from Earth while increasingly relying on resources available locally in space. On-demand production of components and materials (e.g., 3D printing and synthetic biology) holds promise to satisfy the evolving set of supplies necessary to outfit human missions to space. We consider here life support systems for missions planned in the 2020s, and discuss how the maker and 'do-it-yourself' (DIY) biology communities can develop rapid, on-demand manufacturing techniques and platforms to address these needs. This Opinion invites the diverse maker community into building the next generation of flight hardware for near-term space exploration.

Combined multi-nozzle deposition and freeze casting process to superimpose two porous networks for hierarchical three-dimensional microenvironment.

An engineered three-dimensional scaffold with hierarchical porosity and multiple niche microenvironments is produced using a combined multi-nozzle deposition-freeze casting technique. In this paper we present a process to fabricate a scaffold with improved interconnectivity and hierarchical porosity. The scaffold is produced using a two-stage manufacturing process which superimposes a printed porous alginate (Alg) network and a directionally frozen ceramic-polymer matrix. The combination of two processes, multi-nozzle deposition and freeze casting, provides engineering control of the microenvironment of the scaffolds over several length scales; including the addition of lateral porosity and the ratio of polymer to ceramic microstructures. The printed polymer scaffold is submerged in a ceramic-polymer slurry and subsequently, both structures are directionally frozen (freeze cast), superimposing and patterning both microenvironments into a single hierarchical architecture. An optional additional sintering step removes the organic material and densifies the ceramic phase to produce a well-defined network of open pores and a homogenous cell wall material composition. The techniques presented in this contribution address processing challenges, such as structure definition, reproducibility and fine adjustments of unique length scales, which one typically encounters when fabricating topological channels between longitudinal and transverse porous networks.