Psychromonas aestuarii sp. nov., a novel bacterial species isolated from estuarine surface sediment

Abstract

Using an isolation chip (iChip), two bacterial strains, MME1T and MME2, exhibiting ovoid to curved rod cell morphologies and white-cream colony pigmentation were isolated from the surface of estuarine sediment at Niv[a] Bugt Strandenge Bird Sanctuary, Denmark (55{degrees}5542.6N 12{degrees}3123.6E). Analysis of the 16S rRNA gene sequence of these isolates suggested them to be members of the genus Psychromonas, as both had above 97.5 % 16S rRNA gene similarity with Psychromonas aquimarina strain JAMM 0404T. Further genomic comparisons suggested MME strains to be representatives of a novel species, having an average nucleotide identity (ANI) < 85 % relative to all other genome sequenced species of the Psychromonas genus. The G+C content was 39.5 mol %. The species was facultative anaerobic, growing optimally at 15 - 20 {degrees}C and pH 7.0. The optimal salinity was lower than for other described species of the genus with 1 - 2 % NaCl, reflecting the estuarine source of isolation. GC-MS analyses identified C16:0, C16:1{omega}7c/ C16:1{omega}7t/ and C14:03OH as the predominant cellular fatty acids. Based on molecular, phenotypic, and chemotaxonomic analyses, we propose that MME1 and MME2 represent a novel species of the genus Psychromonas with the name Psychromonas aestuarii sp. nov. with the MME1T (= DSM 118464T =LMG 33722T) as the type strain.