Resource allocation and extracellular acid-base status in the sea urchin Strongylocentrotus droebachiensis in response to CO₂ induced seawater acidification.

Anthropogenic CO(2) emission will lead to an increase in seawater pCO(2) of up to 80-100 Pa (800-1000 μatm) within this century and to an acidification of the oceans. Green sea urchins (Strongylocentrotus droebachiensis) occurring in Kattegat experience seasonal hypercapnic and hypoxic conditions already today. Thus, anthropogenic CO(2) emissions will add up to existing values and will lead to even higher pCO(2) values >200 Pa (>2000 μatm).

Consistent pattern of local adaptation during an experimental heat wave in a pipefish-trematode host-parasite system.

Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle) as a host and its digenean trematode parasite (Cryptocotyle lingua).

Abenquines A-D: aminoquinone derivatives produced by Streptomyces sp. strain DB634.

New bioactive secondary metabolites, called abenquines, were found in the fermentation broth of Streptomyces sp. strain DB634, which was isolated from the soils of the Chilean highland of the Atacama Desert. They are composed of an amino acid linked to an N-acetyl-aminobenzoquinone.

Food supply and seawater pCO2 impact calcification and internal shell dissolution in the blue mussel Mytilus edulis.

Progressive ocean acidification due to anthropogenic CO(2) emissions will alter marine ecosystem processes. Calcifying organisms might be particularly vulnerable to these alterations in the speciation of the marine carbonate system. While previous research efforts have mainly focused on external dissolution of shells in seawater under saturated with respect to calcium carbonate, the internal shell interface might be more vulnerable to acidification.

Szentiamide, an N-formylated cyclic depsipeptide from Xenorhabdus szentirmaii DSM 16338T.

Szentiamide (1) a new cyclic hexadepsipeptide was isolated from the culture broth of the entomopathogenic bacterium Xenorhabdus szentirmaii DSM 16338T. The structure was elucidated by analysis of one- and two-dimensional NMR spectra and high resolution mass spectrometry. The amino acids were determined to be D-leucine, L-threonine, D-phenylalanine, D-valine, L-tyrosine and L-tryptophane after hydrolysis and derivatization with D-FDVA [Nalpha-(2,4-dinitro-5-fluorophenyl)-D-valinamide].

A quantitative real-time polymerase chain reaction assay for the seagrass pathogen Labyrinthula zosterae.

The protist Labyrinthula zosterae (Phylum Bigyra, sensu Tsui et al. 2009) has been identified as a causative agent of wasting disease in eelgrass (Zostera marina), of which the most intense outbreak led to the destruction of 90% of eelgrass beds in eastern North America and western Europe in the 1930s. Outbreaks still occur today, albeit at a smaller scale.

CO2 induced seawater acidification impacts sea urchin larval development I: elevated metabolic rates decrease scope for growth and induce developmental delay.

Anthropogenic CO(2) emissions are acidifying the world's oceans. A growing body of evidence is showing that ocean acidification impacts growth and developmental rates of marine invertebrates. Here we test the impact of elevated seawater pCO(2) (129 Pa, 1271 μatm) on early development, larval metabolic and feeding rates in a marine model organism, the sea urchin Strongylocentrotus purpuratus.

CO2 induced seawater acidification impacts sea urchin larval development II: gene expression patterns in pluteus larvae.

Extensive use of fossil fuels is leading to increasing CO(2) concentrations in the atmosphere and causes changes in the carbonate chemistry of the oceans which represents a major sink for anthropogenic CO(2). As a result, the oceans' surface pH is expected to decrease by ca. 0.

ModEnzA: Accurate Identification of Metabolic Enzymes Using Function Specific Profile HMMs with Optimised Discrimination Threshold and Modified Emission Probabilities.

Various enzyme identification protocols involving homology transfer by sequence-sequence or profile-sequence comparisons have been devised which utilise Swiss-Prot sequences associated with EC numbers as the training set. A profile HMM constructed for a particular EC number might select sequences which perform a different enzymatic function due to the presence of certain fold-specific residues which are conserved in enzymes sharing a common fold. We describe a protocol, ModEnzA (HMM-ModE Enzyme Annotation), which generates profile HMMs highly specific at a functional level as defined by the EC numbers by incorporating information from negative training sequences.

Eutypoids B-E produced by a Penicillium sp. strain from the North Sea.

Crude extracts of the Penicillium sp. strain KF620 isolated from the North Sea showed antimicrobial activities against Xanthomonas campestris and Candida glabrata. Purification of the extracts led to the isolation of the new aromatic butenolides eutypoids B (1), C (2), D (3), and E (4).

Nocapyrones A-D, gamma-pyrones from a Nocardiopsis strain isolated from the marine sponge Halichondria panicea.

Four new gamma-pyrones, nocapyrones A-D (1-4), were isolated from an organic extract of the Nocardiopsis strain HB383, which was isolated from the marine sponge Halichondria panicea. These are the first gamma-pyrones reported from a Nocardiopsis strain. The structures were elucidated on the basis of one- and two-dimensional NMR experiments and supported by HPLC-UV/MS and HRESIMS analyses.

Population-specificity of heat stress gene induction in northern and southern eelgrass Zostera marina populations under simulated global warming.

Summer heat waves have already resulted in mortality of coastal communities, including ecologically important seagrass meadows. Gene expression studies from controlled experiments can provide important insight as to how species/genotypes react to extreme events that will increase under global warming. In a common stress garden, we exposed three populations of eelgrass, Zostera marina, to extreme sea surface temperatures, simulating the 2003-European heat wave.

Microsatellites reveal origin and genetic diversity of Eurasian invasions by one of the world's most notorious marine invader, Mnemiopsis leidyi (Ctenophora).

Marine invasions are taking place at an increasing rate. When occurring in blooms, zooplanktivorous comb jellies of the genus Mnemiopsis are able to cause pelagic regime shifts in coastal areas and may cause the collapse of commercially important fish populations. Using microsatellites, developed for the first time in the phylum Ctenophora, we show that Mnemiopsis leidyi has colonized Eurasia from two source regions.

Phylogenetic diversity and antimicrobial activities of bryozoan-associated bacteria isolated from Mediterranean and Baltic Sea habitats.

To date, only a small number of investigations covering microbe-bryozoa associations have been carried out. Most of them have focused on a few bryozoan species and none have covered the antibacterial activities of associated bacteria. In the current study, the proportion and phylogenetic classification of Bryozoan-associated bacteria with antimicrobial properties were investigated.

Diel rhythm of nitrogen and carbon metabolism in the unicellular, diazotrophic cyanobacterium Crocosphaera watsonii WH8501.

We examined the diel variation in nitrogen and carbon metabolism in Crocosphaera watsonii WH8501 at the physiological and gene expression level in order to determine the temporal constraints for N2 fixation and photosynthesis. N2 fixation and photosynthesis were restricted to the dark and light periods, respectively, during a 24 h light-dark cycle. All genes studied here except one (psbA2) showed diel variations in their expression levels.

Mitochondrial phylogeography of the European sprat (Sprattus sprattus L., Clupeidae) reveals isolated climatically vulnerable populations in the Mediterranean Sea and range expansion in the northeast Atlantic.

We examined the genetic structure of the European sprat (Sprattus sprattus) by means of a 530-bp sequence of the mitochondrial control region from 210 fish originating from seven sampling localities of its distributional range. Phylogeographical analysis of 128 haplotypes showed a phylogenetic separation into two major clades with the Strait of Sicily acting as a barrier to gene flow between them. While no population differentiation was observed based on analysis of molecular variance and net nucleotide differences between samples of the Baltic Sea, the North Sea and the Bay of Biscay nor between the Black Sea and the Bosporus, a strong population differentiation between these samples and two samples from the Mediterranean Sea was found.

Microbial CO(2) fixation and sulfur cycling associated with low-temperature emissions at the Lilliput hydrothermal field, southern Mid-Atlantic Ridge (9 degrees S).

Lilliput was discovered in 2005 as the southernmost known hydrothermal field along the Mid-Atlantic Ridge. It is exceptional in that it lacks high-temperature venting probably because of a thickened crust. The absence of thermophilic and hyperthermophilic prokaryotes in emissions supports the argument against the presence of a hot subsurface at Lilliput, as is typically suggested for diffuse emissions from areas of high-temperature venting.