Cell-to-cell DNA Transfer among Thermus Species

Abstract

The ability to transfer DNA via direct cell-to-cell contact-dependent process similar to conjugation has been described in Thermus thermophilus (Tth). Here, we detail the mating experiment protocol involving the lateral transfer of thermostable antibiotic resistance markers (i.e., kanamycin: KmR; hygromycin: HygR) between Thermus cells, enabling the selection and quantification of the transfer frequencies. Briefly, liquid cultures of both mates are mixed and laid onto a nitrocellulose filter on a TB plate. After incubation at 60 °C, filters are resuspended upon selective plating. The contribution of DNA uptake by transformation is abolished by the addition of DNase I to the mix. This protocol can be used for the transfer of large DNA fragments (> 10 kb) to Thermus species.