title: Ecology of marine Bacteroidetes: a comparative genomics approach.
abstract: Bacteroidetes are commonly assumed to be specialized in degrading high molecular weight (HMW) compounds and to have a preference for growth attached to particles, surfaces or algal cells. The first sequenced genomes of marine Bacteroidetes seemed to confirm this assumption. Many more genomes have been sequenced recently. Here, a comparative analysis of marine Bacteroidetes genomes revealed a life strategy different from those of other important phyla of marine bacterioplankton such as Cyanobacteria and Proteobacteria. Bacteroidetes have many adaptations to grow attached to particles, have the capacity to degrade polymers, including a large number of peptidases, glycoside hydrolases (GHs), glycosyl transferases, adhesion proteins, as well as the genes for gliding motility. Several of the polymer degradation genes are located in close association with genes for TonB-dependent receptors and transducers, suggesting an integrated regulation of adhesion and degradation of polymers. This confirmed the role of this abundant group of marine bacteria as degraders of particulate matter. Marine Bacteroidetes had a significantly larger number of proteases than GHs, while non-marine Bacteroidetes had equal numbers of both. Proteorhodopsin containing Bacteroidetes shared two characteristics: small genome size and a higher number of genes involved in CO2 fixation per Mb. The latter may be important in order to survive when floating freely in the illuminated, but nutrient-poor, ocean surface.
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Fernández-Gómez
authors.forename: Michael
authors.initials: M
authors.lastname: Richter
authors.forename: Margarete
authors.initials: M
authors.lastname: Schüler
authors.forename: Jarone
authors.initials: J
authors.lastname: Pinhassi
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Acinas
authors.forename: José M
authors.initials: JM
authors.lastname: González
authors.forename: Carlos
authors.initials: C
authors.lastname: Pedrós-Alió
mesh_terms: D001422:Bacterial Adhesion; D041963:Bacteroidetes / Q000145:classification* / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D004463:Ecology; D016680:Genome, Bacterial; D023281:Genomics / Q000379:methods*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D008124:Locomotion; D008969:Molecular Sequence Data; D012623:Seawater / Q000382:microbiology*
chemical_list: D016695:Glycosyltransferases