title: Bacterial Diversity in the Soda Saline Crater Lake from Isabel Island, Mexico.
abstract: Isabel Lake is a moderate saline soda crater lake located in Isabel Island in the eastern tropical Pacific coast of Mexico. Lake is mainly formed by rainfall and is strongly affected by evaporation and high input of nutrients derived from excretions of a large bird community inhabiting the island. So far, only the island macrobiota has been studied. The knowledge of the prokaryotic biota inhabiting the upper layers of this meromictic lake can give clues for the maintenance of this ecosystem. We assessed the diversity and composition of prokaryotic community in sediments and water of the lake by DGGE profiling, 16S rRNA gene amplicon pyrosequencing, and cultivation techniques. The bacterial community is largely dominated by halophilic and halotolerant microorganisms. Alpha diversity estimations reveal higher value in sediments than in water (P > 0.005). The lake water is dominated by γ-Proteobacteria belonging to four main families where Halomonadaceae presents the highest abundance. Aerobic, phototrophic, and halotolerant prokaryotes such as Cyanobacteria GPIIa, Halomonas, Alcanivorax, Idiomarina, and Cyclobacterium genera are commonly found. However, in sediment samples, Formosa, Muricauda, and Salegentibacter genera corresponding to Flavobacteriaceae family accounted for 15-20 % of the diversity. Heterotrophs like those involved in sulfur cycle, Desulfotignum, Desulfuromonas, Desulfofustis, and Desulfopila, appear to play an important role in sediments. Finally, a collection of aerobic halophilic bacterial isolates was created from these samples; members of the genus Halomonas were predominantly isolated from lake water. This study contributes to state the bacterial diversity present in this particular soda saline crater lake.
authors.affiliation: Grupo de Ecología Genética, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/ Profesor Albareda 1, 18008, Granada, Spain.|Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana, Unidad Xochimilco, Calz. del Hueso 1110, CP 14310, DF México, Mexico.
authors.forename: José Félix
authors.initials: JF
authors.lastname: Aguirre-Garrido
authors.affiliation: Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana, Unidad Xochimilco, Calz. del Hueso 1110, CP 14310, DF México, Mexico.
authors.forename: Hugo César
authors.initials: HC
authors.lastname: Ramírez-Saad
authors.affiliation: Grupo de Ecología Genética, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/ Profesor Albareda 1, 18008, Granada, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Toro
authors.affiliation: Grupo de Ecología Genética, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, C/ Profesor Albareda 1, 18008, Granada, Spain. fmabarca@eez.csic.es.
authors.forename: Francisco
authors.initials: F
authors.lastname: Martínez-Abarca
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D044822:Biodiversity; D062312:Islands; D060106:Lakes / Q000032:analysis / Q000382:microbiology*; D008800:Mexico; D008969:Molecular Sequence Data; D010802:Phylogeny; D012965:Sodium Chloride / Q000032:analysis / Q000378:metabolism
chemical_list: D012965:Sodium Chloride
keywords: 16S rRNA analysis; 454-Amplitag-pyrosequencing; Alkaline and hypersaline environment; Halo-alkalophile bacteria