Immunohistochemical characterization of polyclonal antibodies against Enteromyxum leei and Enteromyxum scophthalmi (Myxozoa: Myxosporea), intestinal parasites of fish

The enteric myxozoan parasites Enteromyxum leei (Diamant, Lom et Dyková) and Enteromyxum scophthalmi Palenzuela, Redondo et Álvarez‐Pellitero are responsible for high weight loss in infected fish, which leads to subchronic disease and low mortality rates in gilthead sea bream (GSB), Sparus aurata L., and to high mortality rates in turbot, Psetta maxima (L.). The detection of initial parasite stages in histological sections is particularly difficult, but can be simplified by means of specific antibodies. Rabbit polyclonal antibodies (pAbs) were raised against E. scophthalmi and E. leei, and direct enzyme‐linked immunosorbent assay (ELISA) and immunohistochemistry were used to characterize their sensitivity and specificity. Both pAbs were adsorbed (apAb) with non‐infected intestines to avoid non‐specific labelling of fish tissues and to improve their specificity. The highest titre obtained in ELISA was 1: 32 000 for apAb‐Eleei and 1:16 000 for apAb‐Escoph. Working dilutions in immunohistochemistry were 1:1000 for apAb‐Eleei and 1:8000 for apAb‐Escoph. Both apAbs labelled proliferative and sporogonic stages with high specificity. apAb‐Escoph was very specific, whereas apAb‐Eleei cross‐reacted with Sphaerospora dicentrarchi Sitjà‐Bobadilla et Álvarez‐Pellitero and Sphaerospora testicularis Sitjà‐Bobadilla et Álvarez‐Pellitero, suggesting the presence of shared antigens. These pAbs stand as new tools for antigenic characterization and the diagnosis of both Enteromyxum species.     

Aeroplysinin-1, a Sponge-Derived Multi-Targeted Bioactive Marine Drug

Organisms lacking external defense mechanisms have developed chemical defense strategies, particularly through the production of secondary metabolites with antibiotic or repellent effects. Secondary metabolites from marine organisms have proven to be an exceptionally rich source of small molecules with pharmacological activities potentially beneficial to human health. (+)-Aeroplysinin-1 is a secondary metabolite isolated from marine sponges with a wide spectrum of bio-activities. (+)-Aeroplysinin-1 has potent antibiotic effects on Gram-positive bacteria and several dinoflagellate microalgae causing toxic blooms. In preclinical studies, (+)-aeroplysinin-1 has been shown to have promising anti-inflammatory, anti-angiogenic and anti-tumor effects. Due to its versatility, (+)-aeroplysinin-1 might have a pharmaceutical interest for the treatment of different pathologies.     

Isolation and use of beneficial microbiota from the digestive tract of lions‐paw scallop Nodipecten subnodosus and winged pearl oyster Pteria sterna in oyster aquaculture

We isolated microbiota from the digestive tract of Nodipecten subnodosus and Pteria sterna and determined in vitro their haemolytic activity, antagonism against Vibrio spp., bacterial hydrophobicity, production of extracellular enzymes and molecular identification. Five bacterial strains were selected: RL5 and C3 (Lactobacillus spp.) and PB1‐1, PB1‐5 and PB1‐6 (Bacillus spp.). The RL5 and C3 isolates showed antimicrobial activity against Vibrio spp. and the PB1‐1, PB1‐5 and PB1‐6 isolates showed enzymatic activity for amylase, protease, lipase and cellulose; the C3 and PB1‐5 isolates were highly hydrophobic. The selected strains of bacteria were tested in vivo as probiotics, together with a treatment of ampicillin and a control without bacteria on juvenile Kumamoto oysters Crassostrea sikamea. The strains were provided individually and as mixes of isolates. Survival, growth and biochemical composition of the juveniles were determined as in vivo indicators. Juveniles grew significantly larger and faster when treated with a specific mix of isolates (MIX‐B), compared with the control. The protein, lipid and carbohydrate concentrations were also significantly higher in oysters exposed to probiotic treatments, compared with the control and the antibiotic treatment. The selected microbiota showed probiotic proprieties for cultivating C. sikamea juveniles.     

Insect larvae as feed ingredient selectively increase arachidonic acid content in farmed gilthead sea bream (Sparus aurata L.)

This work is aimed at obtaining farmed fish designed to contain targeted PUFAs. To this end, an experiment was conducted with farmed specimens of gilthead sea bream (Sparus aurata L.), which were fed meal containing different percentages of common green bottle fly (Lucilia sericata Meigen) larvae, cultured on appropriate substrates, and then the fatty acid profiles in fish muscles were determined. Results indicate that arachidonic acid content in fish muscle is significantly increased when replacing different proportions of fishmeal by larvae from L. sericata, which contains arachidonic acid up to 10.6% of total fatty acids. Thus, larvae seem to be a suitable vector for introducing target PUFA in fish muscle and it could also contribute to reduce the use of wild fish stocks for fishmeal production.     

Bioaccessibility of Phenolic Compounds and Antioxidant Capacity of Chia (<Emphasis Type="Italic">Salvia hispanica</Emphasis> L.) Seeds

The aim of this work was to evaluate (i) the phenol and flavonoid recovery and bioaccessibility indexes and (ii) the antioxidant activity of both types of non-defatted and defatted chia seeds during the in vitro gastrointestinal digestion. The ground samples were subjected to in vitro simulated gastrointestinal digestion, and the resultant fractions were extracted and subjected to spectrophotometric assays. The results pointed to increasing concentrations of polyphenolic compounds during digestion, although only a low-medium percentage of phenols and a low percentage of flavonoids were available for absorption in the intestinal tract. In addition, the high level of fats seemed to have a negative effect on the bioaccessibility of flavonoids. Further studies should be undertaken to better understand the stabilization of the bioactive compounds of chia and to improve their bioaccessibility. Meanwhile, the present study represents a solid base for studying the bioavailability of bioactive compounds of chia seeds.     

A taper function for Pseudotsuga menziesii plantations in Spain

Five stem taper models belonging to three different taper function categories were fitted to data corresponding to 282 Pseudotsuga menziesii trees. The trees were selected in the area surrounding 61 research plots installed in Galicia, Asturias and the Basque Country, northern Spain. The models were simultaneously fitted to observed values of diameter outside bark and inside bark. A third-order continuous-time autoregressive error structure was used to account for autocorrelation. Selection of the best model was based on both numerical (goodness-of-fit statistics) and graphical analysis (plots of residuals against position along the stem and against tree size). The three-segmented taper model finally selected has the advantage of being compatible with both a merchantable and a total stem volume equation.     

The impact of flood control on the loss of wetlands in Argentina

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