Specific Metabolites in a Phaeodactylum tricornutum Strain Isolated from Western Norwegian Fjord Water

We have searched for special characteristics in growth, protein expression, fatty acids and volatile organic compounds (VOCs) in a local Phaeodactylum tricornutum Bohlin strain (Bergen Marine Biobank), by comparing it with a common accession strain (CCAP). Differences in growth and expressed proteins were detected between the BMB strain and the CCAP strain, and the BMB strain reached the highest cell densities under the given growth conditions. Fatty acid (FA) analyses showed highest relative eicosapentaenoic acid (EPA) levels in the exponential phase (25.73% and 28.31%), and highest levels of palmitoleic acid (16:1 n-7) in the stationary phase (46.36% and 43.66%) in the BMB and CCAP strain, respectively. The most striking finding of the VOCs analyses was the relatively high levels of ectocarpene, 6-((1E)-butenyl)-1,4-cycloheptadiene, hormosirene, and desmarestene and structurally related compounds, which were exclusively detected in the BMB strain. Many of the VOCs detected in the CCAP and, in particular, in the BMB strain have been reported as antimicrobial agents. We suggest that the array of pheromones and antimicrobial substances could be part of an allelopathic strategy of the BMB strain, dominated by oval cells, thus reflecting the benthic life stage of this morphological form. These findings show the potential for bioactive metabolites in the BMB strain.     

Hydrocarbon and Toxic Metal Contamination from Tank Installations in a Northwest Greenlandic Village

Contamination from tank installations in the Arctic is an important issue, since tanks are a necessary feature of all communities, and may be a source of local pollution. Soil samples from below and around three tank installations and one reference site in the Northwest Greenlandic village of Tasiusaq were analysed for the total content of hydrocarbons (THC), lead, cadmium and organic content in the soil. Concentrations up to 77,000?mg/kg DW THC were found, mainly as weathered oil products. Elevated levels of lead and cadmium were also found in many of the samples, with concentrations up to 300 and 2?mg/kg DW, respectively. The tank installation areas were contaminated by THC, lead and cadmium compared to the reference site, and parts of the areas were highly contaminated, exceeding the Danish environmental quality criteria. The correlation between lead and cadmium concentrations was significant (p?<?0.01), while no correlation existed between THC and organic matter. Small spills from daily use of the tank installations are suggested to be the source of the THC contamination, whereas the lead and cadmium contamination is suggested to originate primarily from the plume of smoke from waste incineration.     

Onions: a source of unique dietary flavonoids

Onion bulbs (Allium cepa L.) are among the richest sources of dietary flavonoids and contribute to a large extent to the overall intake of flavonoids. This review includes a compilation of the existing qualitative and quantitative information about flavonoids reported to occur in onion bulbs, including NMR spectroscopic evidence used for structural characterization. In addition, a summary is given to index onion cultivars according to their content of flavonoids measured as quercetin. Only compounds belonging to the flavonols, the anthocyanins, and the dihydroflavonols have been reported to occur in onion bulbs. Yellow onions contain 270-1187 mg of flavonols per kilogram of fresh weight (FW), whereas red onions contain 415-1917 mg of flavonols per kilogram of FW. Flavonols are the predominant pigments of onions. At least 25 different flavonols have been characterized, and quercetin derivatives are the most important ones in all onion cultivars. Their glycosyl moieties are almost exclusively glucose, which is mainly attached to the 4', 3, and/or 7-positions of the aglycones. Quercetin 4'-glucoside and quercetin 3,4'-diglucoside are in most cases reported as the main flavonols in recent literature. Analogous derivatives of kaempferol and isorhamnetin have been identified as minor pigments. Recent reports indicate that the outer dry layers of onion bulbs contain oligomeric structures of quercetin in addition to condensation products of quercetin and protocatechuic acid. The anthocyanins of red onions are mainly cyanidin glucosides acylated with malonic acid or nonacylated. Some of these pigments facilitate unique structural features like 4'-glycosylation and unusual substitution patterns of sugar moieties. Altogether at least 25 different anthocyanins have been reported from red onions, including two novel 5-carboxypyranocyanidin-derivatives. The quantitative content of anthocyanins in some red onion cultivars has been reported to be approximately 10% of the total flavonoid content or 39-240 mg kg (-1) FW. The dihydroflavonol taxifolin and its 3-, 7-, and 4'-glucosides have been identified in onions. Although the structural diversity of dihydroflavonols characterized from onions is restricted compared with the wide structural assortment of flavonols and anthocyanins identified, they may occur at high concentrations in some cultivars. From bulbs of the cultivar "Tropea", 5.9 mg of taxifolin 7-glucoside and 98.1 mg of taxifolin have been isolated per kilogram of FW.     

Seasonal variations in the level of plant constituents in greenhouse production of cherry tomatoes

The content of selected plant constituents was measured in cherry tomatoes (Lycopersicon esculentumMill. cv. Jennita) during conventional Norwegian tomato production in a greenhouse from May until October 2004. Samples were collected according to standard production procedure with orange-yellow colored fruits at weight in the range of 12.4-19.3 g and size in the range of 28.9-33.0 mm (diameter). The content of selected compounds based on 100 g FW were found to vary in the following range during the season: 7.38-28.38 mg of chalconaringenin, 0.32-0.92 mg of rutin, 0.24-1.06 mg of chlorogenic acid, 5.60-20.02 mg of ascorbic acid, 1.60-5.54 mg of lycopene, and 0.37-0.55 mg beta-carotene. Only minute amounts of naringenin together with kaempferol 3-rutinoside and caffeic acid, which previously have been reported from tomatoes, were detected. The content of chalconaringenin to rutin and that of lycopene to beta-carotene showed a strong correlation during the season (p < 0.001). The content of total phenolics and methanol-soluble antioxidants also showed a correlation (p < 0.001), and were found in the range 14.6-32.6 mg of gallic acid equivalents (GAE)/100 g fresh weight (FW) and 445-737 micromol of Fe(II)/100 g FW, respectively. Seasonal variation in the level of plant constituents is shown to be related to photon flux density and fertilization level.     

Infectious Salmon Anemia (ISA) Virus: Infectivity in Seawater under Different Physical Conditions

Abstract

Infectious salmon anemia (ISA) virus (genus Isavirus, family Orthomyxoviridae), present in all major salmon producing countries, is the causative agent for a serious and commercially important disease affecting Atlantic Salmon Salmo salar. Nearly all ISA outbreaks occur in the marine production phase and knowledge about survival time for ISA virions in seawater is crucial for an adequate strategy to combat the disease. To acquire knowledge about this important factor, a study of ISA virus exposed to four different physical conditions was carried out. The virions’ survival was tested in sterile seawater, sterile seawater with normal ultraviolet light radiation (UVR), natural seawater, and natural seawater with UVR. During the 72-h experiment both presence of ISA virus RNA and the infectivity of ISA virions were monitored. The result of this study showed that the infectivity of ISA virions is lost within 3 h of exposure to natural seawater or sterile seawater with UVR. However, it was possible to detect ISA virus RNA throughout the experimental period. This indicates that the effect of both UVR and biological activity of natural seawater limits the survival time of ISA virions under normal conditions. The survival time of ISA virions in sterile seawater was less than 24 h. Based on the available literature and the present study it is not very likely that passive horizontal transmission in seawater over long distances can occur. This is due to the following factors: (1) the effect of UVR and biological activity on ISA virions infectivity found in the present study, (2) the speed and dilution effect in seawater currents in salmon farming areas, (3) the temperature during the major outbreak periods, and (4) the need for an infective dose of ISA virions to reach naive Atlantic Salmon.

Received August 22, 2013; accepted November 7, 2013     

Habitat specificity of patches in modern agricultural landscapes

Habitat specificity analysis provides a tool for partitioning landscape species diversity on landscape elements by separating patches with many rare specialist species from patches with the same number of species, all of which are common generalists and thus provide information of relevance to conservation goals at regional and national levels. Our analyses were based upon species data from 2201 patch elements in SE Norwegian modern agricultural landscapes. The context used for measuring habitat specificity strongly influences the results. In general the gamma diversity contribution and core habitat specificity calculated from the patch data set were correlated. High values for both measures were observed for woodland, pastures and road verges whereas midfield islets and boundary transitional types were ranked low, as opposed to findings in traditional, extensively managed agricultural landscapes. This is due to our study area representing intensively used agricultural landscape elements holding a more trivial species composition, in addition to ruderals being favoured by fertility and disturbance, a finding also being supported by the semi-natural affiliation index. Results obtained by use of checklist data from the same study area diverged from patch data. Caution is needed in interpretation of habitat specificity results obtained from checklist data, because modern agricultural landscapes contain several land types which are seldom surveyed by botanists, thus being under-represented in the data set. We propose the use of core habitat specificity and gamma diversity contribution in parallel to obtain a value neutral diversity assessment that addresses patch uniqueness and other properties of conservation interests.     

Towards an acoustic‐based coupled observation and modelling system for monitoring and predicting ecosystem dynamics of the open ocean

Assessment of open‐ocean ecosystems relies on understanding ecosystem dynamics, and development of end‐to‐end ecosystem models represents an approach that addresses these challenges. These models incorporate the population structure and dynamics of marine organisms at all trophic levels. Satellite remote sensing of ocean colour and direct at‐sea measurements provide information on the lower trophic levels of the models, and fisheries studies provide information on top predator species. However, these models suffer from a lack of observations for the so‐called mid‐trophic levels, which are poorly sampled by conventional methods. This restricts further development, and we argue that acoustic observations from a range of platforms (e.g. buoys, moorings) can be linked to the ecosystem models to provide much‐needed information on these trophic levels. To achieve this, the models need to be tailored to incorporate the available acoustic data, and the link from acoustic backscatter to biologically relevant variables (biomass, carbon, etc.) needs attention. Methods to progress this issue are proposed, including the development of observation models and focal areas for ground truthing. To ensure full use of the potential of acoustic techniques, we argue that a systematic and long‐term strategy incorporating the following elements is required: development of metadata standards and automated data analysis, inclusion of acoustic sensors in large‐scale observatory programmes, improvement of observation‐model links, and efficient sampling strategies. Finally, these elements should be tied together in an observation‐modelling framework, coordinated by international organizations, to improve our understanding and quantification of open‐ocean ecosystem dynamics.     

Growth performance of European whitefish [Coregonus lavaretus (L.)] under a constant light and temperature regime

Growth, feed intake and maturation were monitored in a fast‐growing benthivore morph of European whitefish [Coregonus lavaretus (L.)] held under constant light (LD 24:0) and temperature conditions (10°C) for 415 days. Their growth was best described by polynomial regression model and no indication of seasonal patterns (e.g. winter depression) in growth rates was found. There was no significant difference in food conversion ratio (FCR) between periods during the experiment and the FCR was favourable (0.84). Furthermore, there were no differences in growth between males and females. None of the fish became sexually mature by the time the experiment was terminated, although they had reached a mean size of about 444 g. The European whitefish seems to be a promising aquaculture species as the growth rate was relatively high with a remarkable homogenous growth performance between individual fish within each experimental unit, a relatively favourable FCR, a low degree of agonistic behaviour and negligible growth depression due to internal biological rhythms or gonad maturation. These results were obtained at relatively low temperatures that should be beneficial for sustainable cost‐effective farming conditions in cold climate condition in northern Scandinavia.     

Effects of dietary vegetable oils and varying dietary EPA and DHA levels on intestinal lipid accumulations in Atlantic salmon

High dietary content of vegetable oil (VO) has been associated with increased intestinal lipid accumulations in fish. The extent of this in aquacultured Atlantic salmon (Salmo salar L.) and its health effects are not certain. Samples were therefore collected from two separate feeding trials to investigate the effect of high dietary VO on intestinal lipid accumulations in Atlantic salmon. In the first trial, the fish were fed diets high in plant protein and with fish oil or ~80% of the fish oil replaced with either olive oil, rapeseed oil or soybean oil in a land‐based experimental set‐up. The second trial was performed in sea cages under commercial production conditions, and the fish were fed two dietary concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (9.7% or 5.5% EPA + DHA of total fatty acids). Neither dietary VO nor variations in EPA and DHA led to any significant effects on intestinal health or lipid accumulations. There were, however, indications of a delayed lipid transport in the rapeseed oil‐fed fish of the first trial, possibly caused by high dietary ≥18‐carbon fatty acids and low dietary 16:0 fatty acid and cholesterol.     

The flavonoids of tomatoes

Tomatoes ( Lycopersicon esculentum Mill.) have been recognized as an important source of dietary flavonoids because of a high consumption worldwide. The qualitative and quantitative flavonoid compositions of assorted tomato cultivars including individual quantitative contributions of the five most significant flavonoids have been determined in this work. The dihydrochalcone phloretin 3',5'-di-C-beta-glucopyranoside and the flavonol quercetin 3-O-(2'-O-beta-apiofuranosyl-6'-O-alpha-rhamnopyranosyl-beta-glucopyranoside) were identified for the first time in Solanaceae spp. and found to be among the main flavonoids in all cultivars. Phloretin 3',5'-di-C-glc is the first C-glycoside identified in tomatoes and also the first dihydrochalcone from this species. In addition, chalconaringenin, kaempferol 3-rutinoside, and quercetin 3-rutinoside (rutin), though previously reported to occur in tomato, were fully characterized by extensive use of 2D NMR techniques and high-resolution LCMS. The total flavonoid content of different tomato types varied from 4 to 26 mg 100 (-1) g FW with chalconaringenin as the predominant compound comprising 35 to 71% of the total flavonoid content. The individual quantities of quercetin 3-O-(2'- O-beta-apiofuranosyl-6'- O-alpha-rhamnopyranosyl-beta-glucopyranoside) and phloretin 3',5'-di-C-beta-glucopyranoside was similar to that of rutin in several cultivars.