Antarctic Thraustochytrids as Sources of Carotenoids and High-Value Fatty Acids

Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and carotenoids are needed as human dietary supplements and are essential components in commercial feeds for the production of aquacultured seafood. Microorganisms such as thraustochytrids are potential natural sources of these compounds. This research reports on the lipid and carotenoid production capacity of thraustochytrids that were isolated from coastal waters of Antarctica. Of the 22 isolates, 21 produced lipids containing EPA+DHA, and the amount of these fatty acids exceeded 20% of the total fatty acids in 12 isolates. Ten isolates were shown to produce carotenoids (27.4–63.9 μg/g dry biomass). The isolate RT2316-16, identified as Thraustochytrium sp., was the best producer of biomass (7.2 g/L in five days) rich in carotenoids (63.9 μg/g) and, therefore, became the focus of this investigation. The main carotenoids in RT2316-16 were β-carotene and canthaxanthin. The content of EPA+DHA in the total lipids (34 ± 3% w/w in dry biomass) depended on the stage of growth of RT2316-16. Lipid and carotenoid content of the biomass and its concentration could be enhanced by modifying the composition of the culture medium. The estimated genome size of RT2316-16 was 44 Mb. Of the 5656 genes predicted from the genome, 4559 were annotated. These included genes of most of the enzymes in the elongation and desaturation pathway of synthesis of ω-3 polyunsaturated fatty acids. Carotenoid precursors in RT2316-16 were synthesized through the mevalonate pathway. A β-carotene synthase gene, with a different domain organization compared to the gene in other thraustochytrids, explained the carotenoid profile of RT2316-16.     

Percutaneous catheter-based treatment of pulmonic stenosis and patent ductus arteriosus in a dog

A 6-months old female German shepherd dog was referred for management of congenital heart disease. A diagnosis of pulmonic stenosis (PS) and patent ductus arteriosus (PDA) was confirmed by Doppler echocardiography and cardiac catheterisation. The conditions were treated during a single cardiac catheterisation procedure using percutaneous techniques. Gianturco coil embolisation was used to close the PDA, and the PS was relieved using a balloon valvuloplasty technique.     

The influence of drought and heat stress on the expression of end-use quality parameters of common wheat

The effects of drought and heat stress on quality parameters of wheat (Triticum aestivum) cultivars were studied under field conditions in a 2-year trial (2009–2010) in northwest Mexico. Under no stress conditions, rapid small-scale parameters [protein (GP; FP) content, SDS sedimentation (SDSS), mixograph peak time (MPT), swelling index of glutenin (SIG), and lactic acid retention capacity (LARC)] showed significant relationship with gluten strength (alveograph energy, W) and bread loaf volume (LV). SIG and LARC were better than SDSS and MPT for predicting W, while SDSS was better than W and SIG for predicting bread LV. Most quality traits were primarily controlled by genotype (G), although environment (E) and G × E also had significant effects. Heat and drought stress showed contrasting effects on LARC, MPT, alveograph parameters [tenacity (P), extensibility (L), P/L ratio, W] and LV. Increase in P and decrease in L resulted in higher tenacity (larger P/L), which may explain the smaller loaf volume under drought stress. In contrast, decrease in P and increase in L, may explain the improved bread volume observed under heat stress. It is advisable to select for wheat quality under both favorable and abiotic stress conditions to identify genotypes with quality stability across environments.     

A Conus regularis Conotoxin with a Novel Eight-Cysteine Framework Inhibits CaV2.2 Channels and Displays an Anti-Nociceptive Activity

A novel peptide, RsXXIVA, was isolated from the venom duct of Conus regularis, a worm-hunting species collected in the Sea of Cortez, México. Its primary structure was determined by mass spectrometry and confirmed by automated Edman degradation. This conotoxin contains 40 amino acids and exhibits a novel arrangement of eight cysteine residues (C-C-C-C-CC-CC). Surprisingly, two loops of the novel peptide are highly identical to the amino acids sequence of ω-MVIIA. The total length and disulfide pairing of both peptides are quite different, although the two most important residues for the described function of ω-MVIIA (Lys2 and Tyr13) are also present in the peptide reported here. Electrophysiological analysis using superior cervical ganglion (SCG) neurons indicates that RsXXIVA inhibits Ca_V2.2 channel current in a dose-dependent manner with an EC₅₀ of 2.8 μM, whose effect is partially reversed after washing. Furthermore, RsXXIVA was tested in hot-plate assays to measure the potential anti-nociceptive effect to an acute thermal stimulus, showing an analgesic effect in acute thermal pain at 30 and 45 min post-injection. Also, the toxin shows an anti-nociceptive effect in a formalin chronic pain test. However, the low affinity for Ca_V2.2 suggests that the primary target of the peptide could be different from that of ω-MVIIA.     

Iron oxide‐humic acid coprecipitates as iron source for cucumber plants

In soil, iron (Fe) solubility depends on complex interactions between Fe minerals and organic matter, but very little is known about plant availability of Fe present in Fe oxides associated with humic substances. For this purpose, this study investigates the effect of Fe mineral crystallinity in the presence of humic acids (HA) on Fe availability to plants. Four Fe–HA mineral coprecipitates were prepared, either in the presence or absence of oxygen, i.e., two goethite (G)‐HA samples containing large amounts of Fe as nanocrystalline goethite and ferrihydrite mixed phases, and two magnetite (M)‐HA samples containing crystalline magnetite. Bioavailability studies were conducted in hydroponic systems on cucumber plants (Cucumis sativus L.) grown under Fe deficient conditions and supplied with the Fe–HA coprecipitates containing goethite or magnetite. Results showed that plants grown in the presence of Fe–HA coprecipitates exhibited a complete recovery from Fe deficiency, albeit less efficiently than plants resupplied with Fe‐chelate fertilizer used as control (Fe‐diethylene triamine penta acetic acid, Fe‐DTPA). However, the supply with either G‐ or M–HA coprecipitates produced different effects on plants: G–HA‐treated plants showed a higher Fe content in leaves, while M–HA‐treated plants displayed a higher leaf biomass and SPAD (Soil–Plant Analysis Development) index recovery, as compared to Fe‐DTPA. The distribution of macronutrients in the leaves, as imaged by micro X‐ray fluorescence (µXRF) spectroscopy, was different in G–HA and M–HA‐treated plants. In particular, plants supplied with the poorly crystalline G–HA coprecipitate with a lower Fe/HA ratio showed features more similar to those of fully recovered plants (supplied with Fe‐DTPA). These results highlight the importance of mineral crystallinity of Fe–HA coprecipitates on Fe bioavailability and Fe uptake in hydroponic experiments. In addition, the present data demonstrate that cucumber plants can efficiently mobilize Fe, even from goethite and ferrihydrite mixed phases and magnetite, which are usually considered unavailable for plant nutrition.     

Steam-blanched highbush blueberry (Vaccinium corymbosum L.) juice: phenolic profile and antioxidant capacity in relation to cultivar selection

High-quality standards in blueberry juice can be obtained only taking into account fruit compositional variability and its preservation along the processing chain. In this work, five highbush blueberry cultivars from the same environmental growing conditions were individually processed into juice after an initial blanching step and the influence was studied of the cultivar on juice phenolic content, distribution and relative antioxidant activity, measured as scavenging capacity on the artificial free-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH*). A chromatographic protocol was developed to separate all main phenolic compounds in berries. A total of 15 glycosylated anthocyanins, catechin, galactoside, glucoside, and rhamnoside quercetin 3-derivatives, and main benzoic and cinnamic acids were identified. The total content and relative distribution in anthocyanins, chlorogenic acid, and quercetin of each juice were dependent upon cultivar, and the total content was highly correlated (rxy=0.97) to the antioxidant capacity. A selective protective effect of berry blanching in juice processing can be observed on more labile anthocyanin compounds.     

Geographical characterization of polyfloral and acacia honeys by nuclear magnetic resonance and chemometrics

The importance of geographical origin determination is an increasing and pressing requirement for all foods. Honey is one of the largest studied foods due to its nutritional and medicinal properties in a correct diet. In this paper, a total of 41 honey samples (polyfloral and acacia) from different countries have been analyzed in terms of (1)H NMR spectroscopy coupled with multivariate statistical methods. Unsupervised principal component analysis resulted as an efficient tool in distinguishing (1)H NMR spectra of polyfloral and acacia honey samples and for geographical characterization of the latter ones. Hierarchical projection to latent structures discriminant analysis was successfully applied for the discrimination among polyfloral honey samples of different geographical origins. (13)C NMR spectroscopy was applied to honey samples with the aim to investigate possible sugar isoforms differentiation. Our preliminary data indicated a different isoforms ratio between betaFP and betaFF only for polyfloral Argentinean samples, while Hungarian samples showed resonance shifts for some carbons of alphaFF, betaFP, betaFF, and alphaGP isoforms for both varieties. These data confirmed the potentiality of (13)C spectroscopy in food characterization, especially in sugar-based foods.     

Changes in the chemical composition of reduced cooked musts during the heating process

Cooked must is the starting raw material in Aceto Balsamico Tradizionale di Modena (ABTM) production, and the cooking process is a crucial step to ensure quality and safety standards. In particular, the furfural content has to be strictly monitored. In this study, we followed, directly at the production plant, nine cooking processes, differing for grape type and process conditions in order to monitor the actual variability in cooked must reduction. 5-Hydroxymethylfurfural (5-HMF) and furfural contents were determined by high performance liquid chromatography (HPLC) technique and glucose, fructose, and tartaric and malic acids by gas chromatography (GC) technique. Furthermore, some bulk properties, such as the water content, refractive index, density, and total acidity, were also measured. The obtained results show that the product undergoes, in the worse operating conditions, remarkable degradation, leading to extremely high levels of furfurals (5-HMF and furfural), corresponding to a water content lower than 40%. On the basis of these results, a first draft of an optimal heating protocol may be suggested in order to guarantee the safety and quality of the final product.     

Multivariate statistical analysis of mass spectra as a tool for the classification of the main humic substances according to their structural and conformational features

The aim of this work is to explore the suitability of the complementary use of mass spectra and the corresponding statistical analysis (principal components-Pareto analysis (PCA) and discriminant analysis (DA)) of these spectra to differentiate diverse humic samples as a function of their structural and conformational features. To this end, the mass spectra of humic samples belonging to the main humic fraction types (gray humic acid, brown humic acid, and fulvic acid) were obtained by electrospray ionization mass spectrometry (ESI-MS). The results obtained showed that the application of PCA yielded a clear separation between blanks and humic samples. However, a clear differentiation among the humic fraction types was not achieved. The DA of PCA data, however, yielded a clear separation among the humic substances (HS) samples belonging to each HS fraction type considered: gray humic acids, brown humic acids, and fulvic acids. These results showed that the mass spectra of each humic sample include characteristic mass/charge (m/z) distribution values that can be considered as a "fingerprint" representative of its specific structural features. Our results also indicate that, although the m/z values principally corresponded to single-charged ions, we cannot identify these molecular weight distributions with those of humic samples, since sample molecular fragmentation, as well as partial molecular ionization, cannot be ruled out under our experimental and instrumental conditions.     

Suitability of enzyme activities for the monitoring of soil quality improvement in organic agricultural systems

There is growing interest in the applications of soil enzymes as early indicators of soil quality change under contrasting agricultural management practices. However, despite there being an abundant literature on this subject, most comparative assessments have been based on a limited number of experimental farms and, therefore, conclusions are not as robust as desired. In this study, we compare 18 pairs of organic and neighbouring conventional olive orchards in southern Spain. These sites were selected to allow the definition of the relative contributions of site-landscape features, soil type, and time since organic accreditation and tillage intensity, on the soil quality. Soils were analysed for physico-chemical properties, the activities of dehydrogenase, β-glucosidase, arylsulphatase, acid and alkaline phosphatase, and potential nitrification. The geometric mean of the assayed enzymes (GMea) was validated with an independently performed Principal Component Analysis (PCA), and used as a combined soil quality index. The effects of tillage intensity and time since organic accreditation on the improvement of soil quality were also evaluated within the subset of organic farms. Overall for the 18 sites, contrasted management practices did not differ in their impact on basic soil physico-chemical properties, except for loss of on ignition and available inorganic N which were higher and lower in organic farms, respectively. Organic management resulted in significantly higher soil enzyme activities. However, differences were not significant in some of the paired comparisons when considered individually. This highlights the need for extensive comparative assessment, as in this study, to draw clear conclusions concerning the changes to soil quality under sustainable management practices. The GMea was significantly correlated with the first axis of the PCA and shown to be appropriate for condensing the set of soil enzyme values to a sole numerical value. Soil quality changes in organic versus conventional farms, as measured by the GMea, ranged from −23% to 97%, and was highly dependent on time since organic accreditation (r = 0.88; P < 0.01). On the other hand, tillage intensity clearly tended to delay any progress in soil quality in the organic farms.