Brazilian Journal of Microbiology Brazilian Journal of Microbiology
Braz J Microbiol 2018;49:695-702 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2018.02.005
Environmental Microbiology
Phylogenetic MLSA and phenotypic analysis identification of three probable novel Pseudomonas species isolated on King George Island, South Shetland, Antarctica
Felipe Vásquez-Ponce, Sebastián Higuera-Llantén, María S. Pavlov, Sergio H. Marshall, Jorge Olivares-Pacheco,
Pontificia Universidad Católica de Valparaíso, Facultad de Ciencias, Instituto de Biología, Laboratorio de Genética e Inmunología Molecular, Valparaíso, Chile
Received 13 August 2017, Accepted 14 February 2018
Abstract

Antarctica harbors a great diversity of microorganisms, including bacteria, archaea, microalgae and yeasts. The Pseudomonas genus is one of the most diverse and successful bacterial groups described to date, but only eight species isolated from Antarctica have been characterized. Here, we present three potentially novel species isolated on King George Island. The most abundant isolates from four different environments, were genotypically and phenotypically characterized. Multilocus sequence analysis and 16S rRNA gene analysis of a sequence concatenate for six genes (16S, aroE, glnS, gyrB, ileS and rpoD), determined one of the isolates to be a new Pseudomonas mandelii strain, while the other three are good candidates for new Pseudomonas species. Additionally, genotype analyses showed the three candidates to be part of a new subgroup within the Pseudomonas fluorescens complex, together with the Antarctic species Pseudomonas antarctica and Pseudomonas extremaustralis. We propose terming this new subgroup P. antarctica. Likewise, phenotypic analyses using API 20 NE and BIOLOG® corroborated the genotyping results, confirming that all presented isolates form part of the P. fluorescens complex. Pseudomonas genus research on the Antarctic continent is in its infancy. To understand these microorganisms’ role in this extreme environment, the characterization and description of new species is vital.

Keywords
Pseudomonas, Antarctica, P. fluorescens complex, Multilocus Sequence Analysis
Braz J Microbiol 2018;49:695-702 - Vol. 49 Num.4 DOI: 10.1016/j.bjm.2018.02.005