E. coli Adapts to Simulated Microgravity with Stress Response and genomic Changes
new research published in BMC Microbiology reveals how E. coli REL606, a strain cultivated on Earth for 35 years, responds to simulated microgravity (SµG). The study found that SµG considerably impacts gene expression, particularly under glucose-limited conditions, prompting adaptations in stress response, biofilm formation, and metabolic pathways.
Transcriptomic analysis over 24 hours demonstrated that SµG increased the expression of genes associated with the general stress response (GSR) and biofilm production. This effect was more pronounced in cultures experiencing glucose limitation compared to those with ample glucose. These findings suggest that nutrient availability plays a crucial role in how bacteria physiologically adapt to microgravity environments.
Beyond immediate gene expression changes, longer-term SµG cultivation under glucose-limited conditions led to the accumulation of distinct genetic mutations. These mutations were notably found in the mraZ/fruR intergenic region and the elyC gene. The researchers posit that these genomic alterations might potentially be linked to changes in peptidoglycan synthesis and the production of the enterobacterial common antigen (ECA), both critical components of the bacterial cell envelope.
This comprehensive study provides valuable insights into the physiological and genomic adaptations that E. coli undergoes in response to microgravity. The identified changes offer a foundational understanding for future investigations into the long-term evolutionary consequences of space conditions on microbial life,with implications for astrobiology and space exploration.
Simulated microgravity triggers a membrane adaptation to stress in E. coli REL606, BMC Microbiology (open access)
Astrobiology, space biology,
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