sp. nov. and sp. nov., Isolated from the Discovery Deep Brine-Seawater Interface in the Red Sea.

Two extremely halophilic archaeal strains, designated SB29 and SB3, were isolated from the brine-seawater interface of Discovery Deep in the Red Sea. Cells of both strains were pleomorphic (irregular polyhedrals, ovals, and rods) and stained Gram-negative; colonies were pigmented pink. The sequence similarity of the 16S rRNA gene of strain SB29 with that of its most closely related validly described species ( DSM 16227) and that of strain SB3 with its closest validly described relative ( ATCC 35960) was 98.1% and 98.6%, respectively. The incomplete draft genomes of SB29 and SB3 are 3,871,125 bp and 3,904,985 bp in size, respectively, and their DNA G + C contents are 60.75% and 65.64%, respectively. The highest ANI values between the genomes of SB29 and SB3 and the most closely related genomes in GenBank were determined as 82.6% ( ATCC BAA-897, GenBank accession no. GCA_000337835.1) and 92.6% ( ATCC 35960, GenBank accession no. GCA_000337795.1), respectively. These data indicate that the two new isolates cannot be classified into any recognized species of the genus , and, therefore, two novel species of the genus are proposed: sp. nov. (type strain SB29 = JCM 19567 = CGMCC 1.14960) and sp. nov. (type strain SB3 = JCM 19566 = CGMCC 1.14958).