Talaromyces sedimenticola sp. nov., isolated from the Mariana Trench

Two fungal strains (K-2 T and S1) were isolated from the deepest ocean sediment of the Challenger Deep located in the Mariana Trench. The internal transcribed spacer (ITS) gene sequences of the isolates K-2 T and S1 differed from those of closely related species, such as Talaromyces assiutensis and T. trachyspermus . Phylogenetic analyses based on single and concatenated alignments of the genes, namely ITS, β -tubulin ( benA ), calmodulin ( cam ), and the second-largest subunit fragment of the RNA polymerase II ( rpb2 ) showed that the isolates K-2 T and S1 were clustered together with other Talaromyces species , such as T. trachyspermus and T. assiutensis , as evidenced by the position on a terminal branch with high bootstrap support. They could also be distinguished from their closest relatives with valid published names via morphological and physiological characteristics, for example, growth at 4 °C–50 °C with a pH in the range of 1.5–12. Based on their phylogenetic, morphological, and physicochemical properties, the isolates K-2 T and S1 represent a novel species in the genus Talaromyces , and the proposed name is Talaromyces sedimenticola sp. nov. The type strain is K-2 T (= GDMCC 3.746 T = JCM 39451 T ).