Enabling Clonal Analyses of Yeast in Outer Space by Encapsulation and Desiccation in Hollow Microparticles

Abstract

Studying microbes at the single-cell level in space can accelerate human space exploration both via the development of novel biotechnologies and via the understanding of cellular responses to space stressors and countermeasures. High-throughput technologies for screening natural and engineered cell populations can reveal cellular heterogeneity and identify high-performance cells. Here, we present a method to desiccate and preserve microbes in nanoliter-scale compartments, termed PicoShells, which are microparticles with a hollow inner cavity. In PicoShells, single cells are confined in an inner aqueous core by a porous hydrogel shell, allowing the diffusion of nutrients, wastes, and assay reagents for uninhibited cell growth and flexible assay protocols. Desiccated PicoShells offer analysis capabilities for single-cell derived colonies with a simple, low resource workflow, requiring only the addition of water to rehydrate hundreds of thousands of PicoShells and the single microbes encapsulated inside. Our desiccation method results in the recovery of desiccated microparticle morphology and porosity after a multi-week storage period and rehydration, with particle diameter and porosity metrics changing by less than 18% and 7%, respectively, compared to fresh microparticles. We also recorded the high viability of Saccharomyces cerevisiae yeast desiccated and rehydrated inside PicoShells, with only a 14% decrease in viability compared to non-desiccated yeast over 8.5 weeks, although we observed an 85% decrease in initial growth potential over the same duration. We show a proof-of-concept for a growth rate-based analysis of single-cell derived colonies in rehydrated PicoShells, where we identified 11% of the population that grows at an accelerated rate. Desiccated PicoShells thus provide a robust method for cell preservation before and during launch, promising a simple single-cell analysis method for studying heterogeneity in microbial populations in space.

Unveiling the Potential of Single‐Cell Encapsulation in Biomedical Applications: Current Advances and Future Perspectives

“…Qing Quan Liao et al [152] Emulsification (water-oil) Alginate MCF-7 Cell analysis Philipp S. Lienemann et al [52] Emulsification (water-oil) PEG MSC Cell analysis Dongguo Lin et al [153] Emulsification (water-oil) Alginate HCT116 and HT29 Cell analysis Audrey E. Mayfield et al [75] Manual drop-wise encapsulation Agarose CSC Cardiac therapy Ryo Negishi et al [74] Manual drop-wise encapsulation PEGDA HeLa, A549 and NCI-H1975 Cell analysis Simon Ng et al [154] Emulsification (water-oil) PEG-maleimide and DTT S. cerevisiae Enhancement of cell survival Sander Oldenhof et al [155] Imaging-assisted selective capture of cells…”

Protracted Exposure to a Sub-background Radiation Environment Negatively Impacts the Anhydrobiotic Recovery of Desiccated Yeast Sentinels

“…Consequently, research has shown that radiation stress responses in yeast are generally analogous to human cells, albeit with different dose thresholds. Therefore, yeast is widely accepted as a powerful model for stress response research with widespread eukaryotic relevance (Satta et al 1995; Gajendiran and Jeevanram 2002; Yoon et al 2018; Martin-Yken 2020; Santa Maria et al 2020; Ng et al 2022).…”