Pseudomonas laurentiana sp. nov., an Mn(III)-oxidizing Bacterium Isolated from the St. Lawrence Estuary

Introduction: An aerobic, Mn(III)-oxidizing, Gram-negative, motile bacterium (strain GSL-010T) was isolated from deep waters of the St Lawrence Estuary (Canada) and subjected to a polyphasic taxonomic study. Results: Cells were mostly curved, motile rods (1.75 – 2.2 x 0.5 – 0.7 µm) with growth observed at 10 – 37 ºC (optimum at 30 ºC), pH 5 – 10 (optimum at 7.0 – 7.5) and with 0 – 3% (w/v) NaCl (optimum at 0.5%). Phylogenetic analysis based on 16S rRNA gene sequencing revealed strain GSL-010T as a member of the genus Pseudomo- nas, most closely related to the type strains of Pseudomonas plecoglossicida (98.9%) and Pseudomonas japonica (98.6%). The major cellular fatty acids of strain GSL-010T are a combination of C16:1 ω7c and/or iso-C15:1 2-OH, C16:0 and C18:1 ω7c. The G+C mol content of the chromosomal DNA is 59.7%. The DNA–DNA hybridization values between strain GSL-010T and P. plecoglossicida (32.0%) and P. japonica (34.4%) confirm the assignment of the bacterium to a new species. Conclusion: On the basis of phylogenetic analysis, DNA–DNA hy- bridization and physiological and biochemical characterization, strain GSL-010T is clearly a unique bacterium and since it was isolated from the waters of the St. Lawrence estuary, the name Pseudomonas laurentiana sp. nov. is proposed. The type strain is GSL-010T (=JCM 32154T =NBRC 113027T =KCTC 62392T).