Barcoded overexpression screens in gut Bacteroidales identify genes with roles in carbon utilization and stress resistance.

A mechanistic understanding of host-microbe interactions in the gut microbiome is hindered by poorly annotated bacterial genomes. While functional genomics can generate large gene-to-phenotype datasets to accelerate functional discovery, their applications to study gut anaerobes have been limited. For instance, most gain-of-function screens of gut-derived genes have been performed in Escherichia coli and assayed in a small number of conditions. To address these challenges, we develop Barcoded Overexpression BActerial shotgun library sequencing (Boba-seq). We demonstrate the power of this approach by assaying genes from diverse gut Bacteroidales overexpressed in Bacteroides thetaiotaomicron. From hundreds of experiments, we identify new functions and phenotypes for 29 genes important for carbohydrate metabolism or tolerance to antibiotics or bile salts. Highlights include the discovery of a D-glucosamine kinase, a raffinose transporter, and several routes that increase tolerance to ceftriaxone and bile salts through lipid biosynthesis. This approach can be readily applied to develop screens in other strains and additional phenotypic assays.

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.

Towards an extension of equivalent system mass for human exploration missions on Mars.

NASA mission systems proposals are often compared using an equivalent system mass (ESM) framework, wherein all elements of a technology to deliver an effect-its components, operations, and logistics of delivery-are converted to effective masses, which has a known cost scale in space operations. To date, ESM methods and the tools for system comparison largely fail to consider complexities stemming from multiple transit and operations stages, such as would be required to support a crewed mission to Mars, and thus do not account for different mass equivalency factors during each period and the inter-dependencies of the costs across the mission segments. Further, ESM does not account well for the differential reliabilities of the underlying technologies. The uncertainty in the performance of technology should incur an equivalent mass penalty for technology options that might otherwise provide a mass advantage. Here we draw attention to the importance of addressing these limitations and formulate the basis of an extension of ESM that allows for a direct method for analyzing, optimizing, and comparing different mission systems. We outline a preliminary example of applying extended ESM (xESM) through a techno-economic calculation of crop-production technologies as an illustrative case for developing offworld biomanufacturing systems.