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).

Communities of purple sulfur bacteria in a Baltic Sea coastal lagoon analyzed by puf LM gene libraries and the impact of temperature and NaCl concentration in experimental enrichment cultures.

Shallow coastal waters, where phototrophic purple sulfur bacteria (PSB) regularly form massive blooms, are subjected to massive diurnal and event-driven changes of physicochemical conditions including temperature and salinity. To analyze the ability of PSB to cope with these environmental factors and to compete in complex communities we have studied changes of the environmental community of PSB of a Baltic Sea lagoon under experimental enrichment conditions with controlled variation of temperature and NaCl concentration. For the first time, changes within a community of PSB were specifically analyzed using the photosynthetic reaction center genes pufL and M by RFLP and cloning experiments.

New insights into ion regulation of cephalopod molluscs: a role of epidermal ionocytes in acid-base regulation during embryogenesis.

The constraints of an active life in a pelagic habitat led to numerous convergent morphological and physiological adaptations that enable cephalopod molluscs and teleost fishes to compete for similar resources. Here, we show for the first time that such convergent developments are also found in the ontogenetic progression of ion regulatory tissues; as in teleost fish, epidermal ionocytes scattered on skin and yolk sac of cephalopod embryos appear to be responsible for ionic and acid-base regulation before gill epithelia become functional. Ion and acid-base regulation is crucial in cephalopod embryos, as they are surrounded by a hypercapnic egg fluid with a Pco(2) between 0.

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].

Risks of seawater ozonation in recirculation aquaculture--effects of oxidative stress on animal welfare of juvenile turbot (Psetta maxima, L.).

Ozone is frequently used for water treatment and disinfection in recirculating aquaculture systems. However, due to the fragmentary data on chronic toxicity of ozone produced oxidants (OPO) and its safe concentrations, the daily application of ozone in aquaculture is challenging. To evaluate the chronic effects of sublethal OPO concentrations, juvenile turbot (Psetta maxima, L.

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.

Phylogenetic identification of fungi isolated from the marine sponge Tethya aurantium and identification of their secondary metabolites.

Fungi associated with the marine sponge Tethya aurantium were isolated and identified by morphological criteria and phylogenetic analyses based on internal transcribed spacer (ITS) regions. They were evaluated with regard to their secondary metabolite profiles. Among the 81 isolates which were characterized, members of 21 genera were identified.

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.

Levantilides A and B, 20-membered macrolides from a Micromonospora strain isolated from the Mediterranean deep sea sediment.

Two new 20-membered macrolides, levantilide A and B, were isolated from the Micromonospora strain M71-A77. Strain M71-A77 was recovered from an Eastern Mediterranean deep-sea sediment sample and revealed to produce the levantilides under in situ salinity of 38.6 ‰.

Elevated seawater PCO₂ differentially affects branchial acid-base transporters over the course of development in the cephalopod Sepia officinalis.

The specific transporters involved in maintenance of blood pH homeostasis in cephalopod molluscs have not been identified to date. Using in situ hybridization and immunohistochemical methods, we demonstrate that Na(+)/K(+)-ATPase (soNKA), a V-type H(+)-ATPase (soV-HA), and Na(+)/HCO(3)(-) cotransporter (soNBC) are colocalized in NKA-rich cells in the gills of Sepia officinalis. mRNA expression patterns of these transporters and selected metabolic genes were examined in response to moderately elevated seawater Pco(2) (0.

Recent transfer of an iron-regulated gene from the plastid to the nuclear genome in an oceanic diatom adapted to chronic iron limitation.

Background: Although the importance and widespread occurrence of iron limitation in the contemporary ocean is well documented, we still know relatively little about genetic adaptation of phytoplankton to these environments. Compared to its coastal relative Thalassiosira pseudonana, the oceanic diatom Thalassiosira oceanica is highly tolerant to iron limitation. The adaptation to low-iron conditions in T.

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).

Temperature dependency of element incorporation into European eel (Anguilla anguilla) otoliths.

The present study experimentally tested the influence of water temperature on the inclusion of 15 elements into juvenile European eel (Anguilla anguilla) otoliths in freshwater. It should be investigated (1) if temperature effects on otolith Sr/Ca might impair the interpretation of migration studies and (2) if the elemental composition of otoliths can be used to reconstruct experienced temperature histories of eels. Therefore, eels were kept under full experimental conditions at three different water temperatures (14 °C, 19 °C and 24 °C) for 105 days.

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.

Diet composition and feeding of European anchovy Engraulis encrasicolus in Kiel Bight, western Baltic Sea.

Diet composition of the expanding southern species European anchovy Engraulis encrasicolus in the western Baltic Sea was investigated. Results revealed an interesting case of bentho-pelagic coupling with potential implications for local fish species through competition for food resources.

Mayamycin, a cytotoxic polyketide from a Streptomyces strain isolated from the marine sponge Halichondria panicea.

A new benz[a]anthracene derivative called mayamycin (1) was identified in cultures of Streptomyces sp. strain HB202, which was isolated from the marine sponge Halichondria panicea and selected because of its profound antibiotic activity. The ability to produce aromatic polyketides was indicated by genetic analyses, demonstrating the presence of a type II polyketide synthase.

Comprehensive investigation of marine Actinobacteria associated with the sponge Halichondria panicea.

Representatives of Actinobacteria were isolated from the marine sponge Halichondria panicea collected from the Baltic Sea (Germany). For the first time, a comprehensive investigation was performed with regard to phylogenetic strain identification, secondary metabolite profiling, bioactivity determination, and genetic exploration of biosynthetic genes, especially concerning the relationships of the abundance of biosynthesis gene fragments to the number and diversity of produced secondary metabolites. All strains were phylogenetically identified by 16S rRNA gene sequence analyses and were found to belong to the genera Actinoalloteichus, Micrococcus, Micromonospora, Nocardiopsis, and Streptomyces.

Relevance of mytilid shell microtopographies for fouling defence--a global comparison.

Prevention of epibiosis is of vital importance for most aquatic organisms, which can have consequences for their ability to invade new areas. Surface microtopography of the shell periostracum has been shown to have antifouling properties for mytilid mussels, and the topography shows regional differences. This article examines whether an optimal shell design exists and evaluates the degree to which shell microstructure is matched with the properties of the local fouling community.