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.
Project description:The chemically mutagenized Escherichia coli strain AS19 was isolated on the basis of its enhanced sensitivity to different antibiotics, in particular to actinomycin. The strain was later modified to study rRNA modifications that confer antibiotic resistance. Here, we present the genome sequence of the variant E. coli AS19-RrmA.
