Abstract
Deep-space exploration and the establishment of permanent lunar or Martian bases rely heavily on the development of in-situ resource utilization (ISRU) technologies. Among these, biological manufacturing offers a highly efficient path for producing food, pharmaceuticals, and structural materials. However, cosmic radiation—comprising solar particle events and galactic cosmic rays—poses a severe threat to the genomic integrity and metabolic productivity of microbial cell factories. In this study, we engineered the industrial yeast Saccharomyces cerevisiae to withstand simulated cosmic radiation by employing CRISPR-Cas9-mediated transcriptional activation (CRISPRa). We targeted the promoter regions of key endogenous DNA double-strand break repair genes, specifically focusing on the homologous recombination (HR) genes RAD51 and RAD52, and the non-homologous end joining (NHEJ) genes YKU70 and DNL4. The engineered strain, designated CR-Rad-1, demonstrated a 4.2-fold increase in cell viability and sustained a 65% higher yield of a model bioproduct (beta-carotene) under 50 Gy of mixed gamma and proton radiation compared to the wild-type strain. Transcriptomic profiling and comet assays confirmed accelerated DNA repair kinetics and significantly reduced genomic fragmentation. These findings demonstrate that CRISPR-mediated upregulation of endogenous repair machinery is a viable and powerful strategy for safeguarding microbial cell factories during long-duration space missions, paving the way for robust space-based bio-manufacturing.
