Open Access Research article

Genomic and phenotypic attributes of novel salinivibrios from stromatolites, sediment and water from a high altitude lake

Marta F Gorriti12, Graciela M Dias2, Luciane A Chimetto2, Amaro E Trindade-Silva23, Bruno S Silva2, Milene MA Mesquita2, Gustavo B Gregoracci2, Maria E Farias1, Cristiane C Thompson2 and Fabiano L Thompson245*

Author Affiliations

1 Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CCT, CONICET, San Miguel de Tucumán, Tucumán, Argentina

2 Laboratório de Microbiologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brasil

3 Núcleo de Biotecnologia Ambiental, Mestrado Profissional em Tecnologias Aplicáveis a Bioenergia, Faculdade de Tecnologia e Ciências (FTC), Salvador, Brasil

4 SAGE-COPPE, CT2 Rua Moniz de Aragão, no.360 - Bloco 2, Rio de Janeiro, Brasil

5 Av. Carlos Chagas Fo. S/N – CCS – IB –Laboratório de Microbiologia – Bloco A (Anexo) A3 – sl 102 – Cidade Universitária, Rio de Janeiro, RJ, Brasil

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BMC Genomics 2014, 15:473  doi:10.1186/1471-2164-15-473

Published: 13 June 2014

Abstract

Background

Salinivibrios are moderately halophilic bacteria found in salted meats, brines and hypersaline environments. We obtained three novel conspecific Salinivibrio strains closely related to S. costicola, from Socompa Lake, a high altitude hypersaline Andean lake (approx. 3,570 meters above the sea level).

Results

The three novel Salinivibrio spp. were extremely resistant to arsenic (up to 200 mM HAsO42−), NaCl (up to 15%), and UV-B radiation (19 KJ/m2, corresponding to 240 minutes of exposure) by means of phenotypic tests. Our subsequent draft genome ionsequencing and RAST-based genome annotation revealed the presence of genes related to arsenic, NaCl, and UV radiation resistance. The three novel Salinivibrio genomes also had the xanthorhodopsin gene cluster phylogenetically related to Marinobacter and Spiribacter. The genomic taxonomy analysis, including multilocus sequence analysis, average amino acid identity, and genome-to-genome distance revealed that the three novel strains belong to a new Salinivibrio species.

Conclusions

Arsenic resistance genes, genes involved in DNA repair, resistance to extreme environmental conditions and the possible light-based energy production, may represent important attributes of the novel salinivibrios, allowing these microbes to thrive in the Socompa Lake.

Keywords:
Arsenic; Salinity; UV radiation; Xanthorhodopsin; Extreme environment