Salsipaludibacter albus gen. nov., sp. nov., a novel actinobacterial strain isolate from a Portuguese solar saltern and proposal of Salsipaludibacteraceae fam. nov. and Salsipaludibacterales ord. nov.

A novel micro-organism designated AS10(T) was isolated from dry salt collected from Aveiro saltern in the north of Portugal. Cells were Gram-stain-positive, non-motile, non-endospore-forming, rod-shaped and aerobic. Strain AS10(T) was characterized by long filaments of rod-shaped cells, presenting also coccoid cellular forms at the end of the filaments, unveiling some pleomorphism. Rod-shaped cells varied from 0.3 to 0.6 mu m wide and from 0.6 to 2 mu m long. Growth of AS10(T) occurred at 15-40 degrees C (optimum, 20-30 degrees C), 0-10% (w/v) NaCl (optimum, 2%) and pH 4.5-11.0 (optimum, pH 8.0-11.0). The peptidoglycan type was A1 Upsilon-type with 3-hydroxy-diaminopimelic acid. The major fatty acids were C-16(:0), iso-C-1(4:)0, C-17(:0) and C-1(4:)0. The major respiratory quinone was MK-9(H-4). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AS10(T) was similar to actinobacterial members of the class Nitriliruptoria. with Nitriliruptor alkaliphilus ANL-isor being the closest relative the species with a sequence pairwise similarity of 91.21%. Average nucleotide identity, average amino acid identity and in silico DNA-DNA hybridization values between strain AS10(T) and N. alkaliphilus ANL-iso2(T) were 71.34, 53.57 and 18.90%, respectively. The genome DNA G+C content of AS10(T) was 71.8 mol%. Based on genomic, phylogenetic, phenotypic and chemotaxonomic studies, we describe a new species of a novel genus represented by strain AS10(T) (=LMG 31937(T)=CECT 30148(T)) for which we propose the name Salsipaludibacter albus gen. nov., sp. nov. We also propose that this organism represents a new family named Salsipaludibacteraceae fam. nov. of a novel order named Salsipaludibacterales ord. nov.