OUR RESEARCH

Natural Organohalogens

Halogenated compounds are generally viewed as xenobiotics (i.e., foreign to life); however, it is now clear that a plethora of haloorganics is produced naturally. Abiotic reactions, microbes, plants, and animals, including humans, produce halogenated compounds, and the Löffler lab explores the interplay between halogenation and dehalogenation mechanisms to advance understanding of underexplored halogen cycles.

Of note, the conditions on early Earth likely allowed the formation of chlorinated methanes via a radical chain mechanism shown below. We investigate how current day microorganisms metabolize chloromethane (CH₃Cl) and dichloromethane (CH₂Cl₂), and we then want to explore if these metabolic features can be found in places reminiscent of early Earth conditions. The chlorination of methane activates this compound and allowing microbes to metabolize these compounts and conserve energy. This process may have been relevant for driving interdependent, syntrophic community development on early Earth, and may be crucial for sustaining microbial life in energy-constrained environments on current Earth.

Cl₂ → Cl• + Cl•
CH₄ + Cl• → CH₃• + HCl
CH₃• + Cl₂ → CH₃Cl + Cl•
CH₃Cl + Cl• → CH₂Cl• + HCl
CH₂Cl• + Cl₂ → CH₂Cl₂ + Cl•
Sum: CH₄ + 2Cl₂ → CH₂Cl₂ + 2HCl

Abiotic reaction scheme leading
to the formation of CM and DCM.