Diversity and activity of marine bacterioplankton during a diatom bloom in the North Sea assessed by total RNA and pyrotag sequencing.

A recent investigation of bacterioplankton communities in the German Bight towards the end of a diatom-dominated spring phytoplankton bloom revealed pronounced successions of distinct bacterial clades. A combination of metagenomics and metaproteomics indicated that these clades had distinct substrate spectra and consumed different algal substrates. In this study we re-analyzed samples from the initial study by total community RNA (metatranscriptomics) and 16S rRNA gene amplicon sequencing.

Dilution cultivation of marine heterotrophic bacteria abundant after a spring phytoplankton bloom in the North Sea.

The roles of individual bacterioplankton species in the re-mineralization of algal biomass are poorly understood. Evidence from molecular data had indicated that a spring diatom bloom in the German Bight of the North Sea in 2009 was followed by a rapid succession of uncultivated bacterioplankton species, including members of the genera Ulvibacter, Formosa, Polaribacter (class Flavobacteria) and Reinekea (class Gammaproteobacteria). We isolated strains from the same site during the diatom bloom in spring 2010 using dilution cultivation in an artificial seawater medium with micromolar substrate and nutrient concentrations.

Halorhabdus tiamatea: proteogenomics and glycosidase activity measurements identify the first cultivated euryarchaeon from a deep-sea anoxic brine lake as potential polysaccharide degrader.

Euryarchaea from the genus Halorhabdus have been found in hypersaline habitats worldwide, yet are represented by only two isolates: Halorhabdus utahensis AX-2(T) from the shallow Great Salt Lake of Utah, and Halorhabdus tiamatea SARL4B(T) from the Shaban deep-sea hypersaline anoxic lake (DHAL) in the Red Sea. We sequenced the H. tiamatea genome to elucidate its niche adaptations.

The genome of the alga-associated marine flavobacterium Formosa agariphila KMM 3901T reveals a broad potential for degradation of algal polysaccharides.

In recent years, representatives of the Bacteroidetes have been increasingly recognized as specialists for the degradation of macromolecules. Formosa constitutes a Bacteroidetes genus within the class Flavobacteria, and the members of this genus have been found in marine habitats with high levels of organic matter, such as in association with algae, invertebrates, and fecal pellets. Here we report on the generation and analysis of the genome of the type strain of Formosa agariphila (KMM 3901(T)), an isolate from the green alga Acrosiphonia sonderi.

Substrate-controlled succession of marine bacterioplankton populations induced by a phytoplankton bloom.

Phytoplankton blooms characterize temperate ocean margin zones in spring. We investigated the bacterioplankton response to a diatom bloom in the North Sea and observed a dynamic succession of populations at genus-level resolution. Taxonomically distinct expressions of carbohydrate-active enzymes (transporters; in particular, TonB-dependent transporters) and phosphate acquisition strategies were found, indicating that distinct populations of Bacteroidetes, Gammaproteobacteria, and Alphaproteobacteria are specialized for successive decomposition of algal-derived organic matter.

Animal models in influenza vaccine testing.

The threat of a pandemic outbreak of influenza A H5N1 and H2N2 has brought attention to the development of new vaccines. Regulatory authorities require companies to provide data proving the effectiveness of vaccines, which cannot, however, be based on real efficacy data in humans. A weight-of-evidence approach may be used, based on evidence of protection in an appropriate animal model and the satisfaction of the surrogate end points in the clinical situation.