An Interdomain Conjugation Protocol for Plasmid-DNA Transfer into Methanothermobacter thermautotrophicus ΔH

Methanogenic archaea of the order Methanobacteriales are widespread in anaerobic environments and play pivotal roles in microbial communities. The family of Methanobacteriaceae encompasses mesophilic and thermophilic hydrogenotrophic species. Mesophilic species are found in various natural and anthropogenic environments (e.g., are associated with the microbiome in animals and humans). Thermophilic species can be found in thermally active bogs and warm sulfuric springs, but also in anthropogenic environments, such as wastewater treatment plants and anaerobic digesters. Recently, genetic tools for Methanothermobacter thermautotrophicus ΔH, as the first representative of this order of methanogenic archaea, were successfully implemented. This protocol describes the methods for interdomain conjugational DNA transfer from Escherichia coli to M. thermautotrophicus ΔH with shuttle-vector plasmid DNA, which allows the genetic manipulation of this microbe, and provides a basis for the development of further genetic methods for this and potentially other representatives of Methanobacteriales.