Marine microbial communities are structured by a complex interplay of deterministic and stochastic processes, yet how these vary across latitudes remains poorly understood. Most long‐term microbial observatories are restricted to temperate regions, limiting our ability to assess latitudinal contrasts in microbial dynamics. Here, we compare coastal microbial communities from two contrasting marine time‐series stations using sta...

As a top predator, the Iberian Lynx plays a critical role in regulating mesocarnivore communities across the Iberian Peninsula. While species such as the red fox, the Egyptian mongoose, or the European wildcat develop spatial or temporal avoidance behaviours to minimise potentially lethal encounters with the lynx, the relationship between the Eurasian badger and the lynx has been described as one of peaceful coexistence. Howev...

Aerobic anoxygenic phototrophic (AAP) bacteria are a common part of microbial communities in the sunlit ocean. They contain bacteriochlorophyll a (BChl a )‐based photosystems that harvest solar energy for their metabolism. Across different oceanic regions, AAP bacteria seem to be more abundant in eutrophic areas, associated with high chlorophyll concentrations. While most previous studies focused on surface samplings, there is...

Microbes drive the biogeochemical cycles of marine ecosystems through their vast metabolic diversity. While we have a fairly good understanding of the spatial distribution of these metabolic processes in various ecosystems, less is known about their seasonal dynamics. We investigated the annual patterns of 21 biogeochemical relevant functions in an oligotrophic coastal ocean site by analysing the presence of key genes, analysi...

Summary The aerobic anoxygenic phototrophic (AAP) bacteria are common in most marine environments but their global diversity and biogeography remain poorly characterized. Here, we analyzed AAP communities across 113 globally‐distributed surface ocean stations sampled during the Malaspina Expedition in the tropical and subtropical ocean. By means of amplicon sequencing of the puf M gene, a genetic marker for this functional gro...

Aerobic anoxygenic phototrophic (AAP) bacteria are a phylogenetically diverse and ubiquitous group of prokaryotes that use organic matter but can harvest light using bacteriochlorophyll a. Although the factors regulating AAP ecology have long been investigated through field surveys, the few available experimental studies have considered AAPs as a group, thus disregarding the potential differential responses between taxonomical...

Bacteroidetes is one of the dominant phyla of ocean bacterioplankton, yet its diversity and population structure is poorly understood. To advance in the delineation of ecologically meaningful units within this group, we constructed near full‐length 16S rRNA gene clone libraries from contrasting marine environments in the NW Mediterranean. Based on phylogeny and the associated ecological variables (depth and season), 24 differe...

Summary The impact of grazing, resource competition and light on prokaryotic growth and taxonomic composition in subtropical and tropical surface waters were studied through 10 microcosm experiments conducted between 30°N and 30°S in the Atlantic, Pacific and Indian oceans. Under natural sunlight conditions, significant changes in taxonomic composition were only observed after the reduction of grazing by sample filtration in c...

How much temporal recurrence is present in microbial assemblages is still an unanswered ecological question. Even though marked seasonal changes have been reported for whole microbial communities, less is known on the dynamics and seasonality of individual taxa. Here, we aim at understanding microbial recurrence at three different levels: community, taxonomic group and operational taxonomic units (OTUs). For that, we focused o...

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 μm). Further, we studied their v...

Summary Catalysed reporter deposition–fluorescence in situ hybridization ( CARD‐FISH ) is a powerful approach to quantify bacterial taxa. I n this study, we compare the performance of the widely used B acteroidetes CF 319 a probe with the new CF 968 probe. In silico analyses and tests with isolates demonstrate that CF 319 a hybridizes with non‐ B acteroidetes sequences from the R hodobacteraceae and A lteromonadaceae families....

Summary Sequencing of 16S rDNA polymerase chain reaction ( PCR ) amplicons is the most common approach for investigating environmental prokaryotic diversity, despite the known biases introduced during PCR . Here we show that 16S rDNA fragments derived from Illumina‐sequenced environmental metagenomes ( mi tag s) are a powerful alternative to 16S rDNA amplicons for investigating the taxonomic diversity and structure of prokaryo...