The 16S rRNA gene of strain RMAST was amplified using PCR with a slightly modified primer of ARCH21F (DeLong,1992), namely Ar10f-kn (59-TCTGGTTGATCCTGSCRG-39), and Univ1500R and was sequenced as described by Mochimaru et al. (2007). The almost full-length 16S rRNA gene sequence of strain RMAST (1414 bp) was aligned with reference sequences using the online alignment tool SINA (http://www.arb-silva.de; Pruesse et al., 2007). The alignment was imported into the ARB SILVA reference database (SSU_Ref_108) and manually refined using tools available in the ARB software package (Ludwig et al., 2004).