Project description: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 of E. coli REL606, a strain evolved terrestrially for 35 years is explored. We evaluated the transcriptomic changes for glucose-limited and glucose-replete conditions over 24 hours which illustrate that SµG increased the expression of stress response and cell membrane-related genes, particularly under glucose-limited conditions. A machine learning model predicted that glucose-limited SµG impacts the cellular membrane, while glucose-replete SµG also inhibits protein synthesis at stationary phase. These findings highlight the transcriptomic and physiological adaptations of E. coli to short term microgravity, offering a foundation for future research into the long-term effects of space conditions on bacterial evolution.
Project description:Methanol, being electron-rich and derivable from methane or CO2, is a potentially renewable one-carbon (C1) feedstock for microorganisms. Although the ribulose monophosphate (RuMP) cycle used by methylotrophs to assimilate methanol differs from the typical sugar metabolism by only three enzymes, turning a non-methylotrophic organism to a synthetic methylotroph that grows to a high cell density has been challenging. Here, we reprogrammed E. coli using metabolic robustness criteria followed by laboratory evolution to establish a strain that can utilize methanol as the sole carbon source efficiently. This synthetic methylotroph alleviated a heretofore uncharacterized hurdle, DNA-protein crosslinking (DPC), by insertion sequence (IS) mediated copy number variations (CNV) and balanced the metabolic flux by mutations. Being capable of growing at a rate comparable to natural methylotrophs in a wide-range of methanol concentrations, this synthetic methylotrophic strain illustrates genome editing and evolution for microbial tropism changes, and expands the scope of biological C1 conversion.
