title: Patterns of bacterial diversity in the marine planktonic particulate matter continuum.
abstract: Depending on their relationship with the pelagic particulate matter, planktonic prokaryotes have traditionally been classified into two types of communities: free-living (FL) or attached (ATT) to particles, and are generally separated using only one pore-size filter in a differential filtration. Nonetheless, particulate matter in the oceans appears in a continuum of sizes. Here we separated this continuum into six discrete size-fractions, from 0.2 to 200 μm, and described the prokaryotes associated to each of them. Each size-fraction presented different bacterial communities, with a range of 23-42% of unique (OTUs) in each size-fraction, supporting the idea that they contained distinct types of particles. An increase in richness was observed from the smallest to the largest size-fractions, suggesting that increasingly larger particles contributed new niches. Our results show that a multiple size-fractionation provides a more exhaustive description of the bacterial diversity and community structure than the use of only one filter. In addition, and based on our results, we propose an alternative to the dichotomy of FL or ATT lifestyles, in which we differentiate the taxonomic groups with preference for the smaller fractions, those that do not show preferences for small or large fractions, and those that preferentially appear in larger fractions.
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Barcelona, Catalunya, Spain.
authors.forename: Mireia
authors.identifier: 0000-0003-0986-633X
authors.initials: M
authors.lastname: Mestre
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Barcelona, Catalunya, Spain.
authors.forename: Encarna
authors.initials: E
authors.lastname: Borrull
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Barcelona, Catalunya, Spain.
authors.forename: MMontserrat
authors.initials: M
authors.lastname: Sala
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Barcelona, Catalunya, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Gasol
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000166:cytology / Q000235:genetics*; D048429:Cell Size; D009792:Oceans and Seas; D052638:Particulate Matter; D010933:Plankton / Q000145:classification*
chemical_list: D052638:Particulate Matter