TY - JOUR A1 - Mestre, Mireia A1 - Ferrera, Isabel A1 - Borrull, Encarna A1 - Ortega-Retuerta, Eva A1 - Mbedi, Susan A1 - Grossart, Hans-Peter A1 - Gasol, Josep M. A1 - Sala, M. Montserrat T1 - Spatial variability of marine bacterial and archaeal communities along the particulate matter continuum JF - Molecular ecology N2 - Biotic and abiotic particles shape the microspatial architecture that defines the microbial aquatic habitat, being particles highly variable in size and quality along oceanic horizontal and vertical gradients. We analysed the prokaryotic (bacterial and archaeal) diversity and community composition present in six distinct particle size classes ranging from the pico-to the microscale (0.2 to 200 lm). Further, we studied their variations along oceanographic horizontal (from the coast to open oceanic waters) and vertical (from the ocean surface into the meso-and bathypelagic ocean) gradients. In general, prokaryotic community composition was more variable with depth than in the transition from the coast to the open ocean. Comparing the six size-fractions, distinct prokaryotic communities were detected in each size-fraction, and whereas bacteria were more diverse in the larger size-fractions, archaea were more diverse in the smaller size-fractions. Comparison of prokaryotic community composition among particle size-fractions showed that most, but not all, taxonomic groups have a preference for a certain size-fraction sustained with depth. Species sorting, or the presence of diverse ecotypes with distinct size-fraction preferences, may explain why this trend is not conserved in all taxa. KW - attached KW - free-living KW - particulate matter KW - prokaryotic community KW - spatial variability Y1 - 2017 U6 - https://doi.org/10.1111/mec.14421 SN - 0962-1083 SN - 1365-294X VL - 26 SP - 6827 EP - 6840 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Ferrera, Isabel A1 - Sarmento, Hugo A1 - Priscu, John C. A1 - Chiuchiolo, Amy A1 - Gonzalez, Jose M. A1 - Grossart, Hans-Peter T1 - Diversity and Distribution of Freshwater Aerobic Anoxygenic Phototrophic Bacteria across a Wide Latitudinal Gradient JF - Frontiers in microbiology N2 - Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient). KW - AAP bacteria KW - photoheterotrophy KW - pufM gene KW - freshwater lakes KW - latitudinal gradients KW - biogeography Y1 - 2017 U6 - https://doi.org/10.3389/fmicb.2017.00175 SN - 1664-302X VL - 8 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Cuadrat, Rafael R. C. A1 - Ferrera, Isabel A1 - Großart, Hans-Peter A1 - Davila, Alberto M. R. T1 - Picoplankton Bloom in Global South? A High Fraction of Aerobic Anoxygenic Phototrophic Bacteria in Metagenomes from a Coastal Bay (Arraial do Cabo-Brazil) JF - OMICS : a journal of integrative biology N2 - Marine habitats harbor a great diversity of microorganism from the three domains of life, only a small fraction of which can be cultivated. Metagenomic approaches are increasingly popular for addressing microbial diversity without culture, serving as sensitive and relatively unbiased methods for identifying and cataloging the diversity of nucleic acid sequences derived from organisms in environmental samples. Aerobic anoxygenic phototrophic bacteria (AAP) play important roles in carbon and energy cycling in aquatic systems. In oceans, those bacteria are widely distributed; however, their abundance and importance are still poorly understood. The aim of this study was to estimate abundance and diversity of AAPs in metagenomes from an upwelling affected coastal bay in Arraial do Cabo, Brazil, using in silico screening for the anoxygenic photosynthesis core genes. Metagenomes from the Global Ocean Sample Expedition (GOS) were screened for comparative purposes. AAPs were highly abundant in the free-living bacterial fraction from Arraial do Cabo: 23.88% of total bacterial cells, compared with 15% in the GOS dataset. Of the ten most AAP abundant samples from GOS, eight were collected close to the Equator where solar irradiation is high year-round. We were able to assign most retrieved sequences to phylo-groups, with a particularly high abundance of Roseobacter in Arraial do Cabo samples. The high abundance of AAP in this tropical bay may be related to the upwelling phenomenon and subsequent picoplankton bloom. These results suggest a link between upwelling and light abundance and demonstrate AAP even in oligotrophic tropical and subtropical environments. Longitudinal studies in the Arraial do Cabo region are warranted to understand the dynamics of AAP at different locations and seasons, and the ecological role of these unique bacteria for biogeochemical and energy cycling in the ocean. Y1 - 2016 U6 - https://doi.org/10.1089/omi.2015.0142 SN - 1536-2310 SN - 1557-8100 VL - 20 SP - 76 EP - 87 PB - Liebert CY - New Rochelle ER -