Abstract
A Gram-negative, non-motile, non-spore-forming bacterial strain, PR1T, was isolated from a mud core sample containing colonial choanoflagellates near Hog Island, Virginia, USA and its taxonomic position was investigated. Strain PR1T grew optimally at 30°C in the presence of 3% (w/v) NaCl. Strain PR1T contained MK-7 as the major menaquinone as well as carotenoids but lacked pigments of the flexirubin-type. The predominant fatty acids were iso-C15:0 (29.4%), iso-C17:1 ω9c (18.5%), and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c; 11.3%). The major polar lipids detected in strain PR1T were phosphatidylethanolamine as well as other phospholipids, aminophospholipids, and lipids of unknown character. The DNA G+C content was 38.7% mol. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PR1T fell within the clade comprising Algoriphagus species, clustering with Algoriphagus halophilus JC 2051T (95.4% sequence similarity) and Algoriphagus lutimaris S1-3T (95.3% sequence similarity). The 16S rRNA gene sequence similarity between strain PR1T and the type strains of other Algoriphagus species were in the range of 91-95%. Differential phenotypic properties and phylogenetic and genetic distinctiveness of strain PR1T demonstrated that this strain was distinct from other Algoriphagus species, including its closest relative, A. halophilus. Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strain PR1T should be placed into the genus Algoriphagus as a novel species, for which the name Algoriphagus machipongonensis sp. nov. is proposed. The type strain is PR1T (= ATCC BAA-2233 T = DSM 24695 T).