Simulated microgravity triggers a membrane adaptation to stress in E. coli REL606

Area of Science:

• Microbiology
• Space Biology
• Genomics

Background:

• Microbial adaptation to extreme environments is crucial for understanding life's resilience.
• Escherichia coli (E. coli) serves as a model organism to study evolutionary responses.
• Space exploration necessitates understanding bacterial behavior in microgravity.

Purpose of the Study:

• To investigate the effects of simulated microgravity (SµG) on gene expression and genome evolution in E. coli REL606.
• To identify physiological and genomic adaptations of E. coli to microgravity conditions.
• To provide insights into bacterial evolution in extreme environments.

Main Methods:

• Exposure of E. coli REL606 to simulated microgravity (SµG) under glucose-limited and glucose-replete conditions.
• Transcriptomic analysis over 24 hours to assess gene expression changes.
• Long-term SµG culture and comparative genomic analysis to identify mutations.

Main Results:

• SµG increased the expression of genes related to stress response, biofilm formation, and metabolism.
• Differential gene expression was more pronounced under glucose-limited conditions compared to glucose-replete conditions.
• Long-term SµG culture resulted in unique mutations, particularly in the mraZ/fruR intergenic region and the elyC gene.

Conclusions:

• E. coli exhibits significant physiological and genomic adaptations to simulated microgravity.
• Microgravity influences stress response, biofilm formation, and metabolic pathways.
• These findings lay the groundwork for future research on long-term space effects on bacteria.