Lozzi Brittney, Adepoju Lea, Espinoza Josh L, Padgen Michael, Parra Macarena, Ricco Antonio, Castro-Wallace Sarah, Barrick Jeffrey E, O'Rourke Aubrie
Space Center Office of STEM Engagement (OSTEM) Intern Program, NASA Kennedy, Kennedy Space Center, Merritt Island, FL, 32899, USA.
Program in Genetics and Genomics, Baylor College of Medicine, Houston, TX, 77030, USA.
BMC Microbiol. 2025 Jun 9;25(1):362. doi: 10.1186/s12866-025-04064-7.
Investigating the evolution of Escherichia coli in microgravity offers valuable insights into microbial adaptation to extreme environments. Here the effects of simulated microgravity (SµG) on gene expression and genome evolution of E. coli REL606, a strain evolved terrestrially for 35 years, is explored. The transcriptomic changes for glucose-limited and glucose-replete conditions over 24 h illustrate that SµG increased the expression of genes involved in stress response, biofilm, and metabolism. A greater number of differentially expressed genes related to the general stress response (GSR) and biofilm formation is observed in simulated microgravity cultures under glucose-limited conditions in comparison to glucose-replete conditions. Longer term SµG culture under glucose-limited conditions led to the accumulation of unique mutations when compared to control cultures, particularly in the mraZ/fruR intergenic region and the elyC gene, suggesting changes in peptidoglycan and enterobacterial common antigen (ECA) production. These findings highlight the physiological and genomic adaptations of E. coli to microgravity, offering a foundation for future research into the long-term effects of space conditions on bacterial evolution.
研究大肠杆菌在微重力环境下的进化，有助于深入了解微生物对极端环境的适应性。本文探究了模拟微重力（SµG）对大肠杆菌REL606基因表达和基因组进化的影响，该菌株在地球上已进化了35年。对24小时内葡萄糖限制和葡萄糖充足条件下的转录组变化研究表明，SµG增加了参与应激反应、生物膜形成和代谢的基因表达。与葡萄糖充足条件相比，在葡萄糖限制条件下的模拟微重力培养物中，观察到更多与一般应激反应（GSR）和生物膜形成相关的差异表达基因。与对照培养物相比，在葡萄糖限制条件下的长期SµG培养导致独特突变的积累，特别是在mraZ/fruR基因间区域和elyC基因中，这表明肽聚糖和肠杆菌共同抗原（ECA）的产生发生了变化。这些发现突出了大肠杆菌对微重力的生理和基因组适应性，为未来研究空间条件对细菌进化的长期影响奠定了基础。
