Production of Chondroitin Sulphate from Head,Skeleton and Fins of Scyliorhinus canicula By-Products by Combination of Enzymatic,Chemical Precipitation and Ultrafiltration Methodologies

This study illustrates the optimisation of the experimental conditions of three sequential steps for chondroitin sulphate (CS) recovery from three cartilaginous materials of Scyliorhinus canicula by-products. Optimum conditions of temperature and pH were first obtained for alcalase proteolysis of head cartilage (58 °C/pH 8.5/0.1% (v/w)/10 h of hydrolysis). Then, similar optimal conditions were observed for skeletons and fin materials. Enzymatic hydrolysates were subsequently treated with a combination of alkaline hydroalcoholic saline solutions in order to improve the protein hydrolysis and the selective precipitation of CS. Ranges of 0.53–0.64 M (NaOH) and 1.14–1.20 volumes (EtOH) were the levels for optimal chemical treatment depending on the cartilage origin. Finally, selective purification and concentration of CS and protein elimination of samples obtained from chemical treatment, was assessed by a combination of ultrafiltration and diafiltration (UF-DF) techniques at 30 kDa.     

Proteolytic digestive enzymes and peritrophic membranes during the development of Plodia interpunctella (Lepidoptera: Piralidae): targets for the action of soybean trypsin inhibitor (SBTI) and chitin-binding vicilin (EvV)

The digestive system of P. interpunctella was characterized during its larval development to determine possible targets for the action of proteinaceous enzyme inhibitors and chitin-binding proteins. High proteolytic activities using azocasein at pH 9.5 as substrate were found. These specific enzymatic activities (AU/mg protein) showed an increase in the homogenate of third instar larvae, and when analyzed by individual larvae (AU/gut), the increase was in sixth instar larvae. Zymograms showed two bands corresponding to those enzymatic activities, which were inhibited by TLCK and SBTI, indicating that the larvae mainly used serine proteinases at pH 9.5 in their digestive process. The presence of a peritrophic membrane in the larvae was confirmed by chemical testing and light microscopy. In a bioassay, P. interpunctella was not susceptible to the soybean trypsin inhibitor, which did not affect larval mass and mortality, likely due to the weak association with its target digestive enzyme. EvV (Erythrina velutina vicilin), when added to the diet, affected mortality (LD50 0.23%) and larval mass (ED50 0.27%). This effect was associated with EvV-binding to the peritrophic membrane, as seen by immunolocalization. EvV was susceptible to gut enzymes and after the digestion process, released an immunoreactive fragment that was bound to the peritrophic matrix, which probably was responsible for the action of EvV.     

Identification of shark species in seafood products by forensically informative nucleotide sequencing (FINS)

The identification of commercial shark species is a relevant issue to ensure the correct labeling of seafood products, to maintain consumer confidence in seafood, and to enhance the knowledge of the species and volumes that are at present being captured, thus improving the management of shark fisheries. The polymerase chain reaction was employed to obtain a 423 bp amplicon from the mitochondrial cytochrome b gene. The sequences from this fragment, belonging to 63 authentic individuals of 23 species, were analyzed using a genetic distance method. Nine different samples of commercial fresh, frozen, and convenience food were obtained in local and international markets to validate the methodology. These samples were analyzed, and sequences were employed for species identification, showing that forensically informative nucleotide sequencing (FINS) is a suitable technique for identification of processed seafood containing shark as an ingredient. The results also showed that incorrect labeling practices may occur regarding shark products, probably because of incorrect labeling at the production point.     

Index of geoaccumulation and spatial distribution of potentially toxic elements in the Serra Pelada gold mine

Journal of Soils and Sediments - The concentration and spatial distribution of many potentially toxic elements (PTEs) have not been studied in the mining areas of tropical soils in the Amazon. The...     

Fish farming of native species in Colombia: current situation and perspectives

In Colombia and the rest of the world, the decrease in capture fisheries production has turned the aquaculture into an alternative source of protein for the populations food security as well as an important productive activity, generating employment and income for the rural communities. The Colombian pisciculture is based on red Tilapia Oreochromis sp. (Linnaeus), Rainbow trout Oncorhynchus mykiss (Walbaum) and cachama blanca Piaractus brachypomus (Cuvier), which currently represent around 96% of the total national production. The remaining 4% comes from other farmed species such as bocachico Prochilodus magdalenae (Steindachner), carp Cyprinus carpio (Linnaeus) and yamúBrycon amazonicus (Spix & Agassiz). From the three main fish species, cachama blanca is the only native species, which has shown excellent performance in pond farming due to its rusticity, omnivorous habits, docility, meat quality, food conversion and disease resistance. The limited offer of Colombian fish farmed species determines its currently low competitiveness and restricted impact on the international markets; thus making necessary to explore the potential of new fish species in order to introduce them to the pisciculture system and to expand the range of fish farming species. A good alternative is the introduction of native catfish, which have great potential for fish farming activity.     

Evaluation of an epidemic of sporotrichosis in cats: 347 cases (1998-2001)

OBJECTIVE: To evaluate characteristics of a large epidemic of sporotrichosis in cats. DESIGN: Retrospective study. ANIMALS: 347 cats with naturally acquired infection with Sporothrix schenckii. PROCEDURE: Medical records were reviewed for data regarding clinical, mycologic, histopathologic, and routine hematologic and serum biochemical findings; assays for FIV-specific antibodies and FeLV antigen; antifungal treatment; and follow-up. RESULTS: Lesions varied from small papules to extensive zones of necrosis.Ten cats had no skin lesions, 114 had skin lesions at a single site, 86 had skin lesions in 2 sites, and 137 had skin lesions in 3 or more sites. Respiratory tract signs were observed in 154 cats and were the most frequent extracutaneous sign. Anemia, leukocytosis with neutrophilia, hypoalbuminemia, and hyperglobulinemia were the main blood abnormalities. Antibodies against FIV were detected in 28 cats, FeLV antigen was detected in 2 cats, and both were detected in 1 cat among 142 cats tested. During the study, 118 cats were lost to follow-up and 124 died. Of 266 cats that were treated, 68 were cured. Complete healing of the lesions was observed regardless of the presence of extracutaneous signs, general condition, treatment schedule, or coinfection with FIV. CONCLUSIONS AND CLINICAL RELEVANCE: Feline sporotrichosis was evident in subclinical to severe forms; however, cats can respond well to regular and prolonged antifungal treatment.     

Solventless Microextraction Techniques for Determination of Trihalomethanes by Gas Chromatography in Drinking Water

Three different solventless sample preparation techniques based on microextraction, membrane extraction, and headspace extraction have been developed and optimized for determination of trihalomethanes in drinking water by gas chromatography electron capture detector and mass spectrometry detection. The techniques employed were headspace (HS) solid-phase microextraction, hollow fiber liquid-phase microextraction (HFLPME) and HS extraction. All techniques used were optimized with different experimental designs in order to select the most relevant variables which significantly affect the different processes. The different analytical figures of merit such as limit of detection (LOD), limit of quantification, reproducibility, accuracy, and linear dynamic range were obtained. The new HFLPME method applied used a hollow fiber membrane of polypropylene and the optimized variables were extraction time, extraction temperature, and salting-out effect. The software MODDE 6.0 was used and its design was one central composite on face with a total of 17 runs. The best conditions for the HFLPME were 20 min, 40°C, and 10% NaCl, respectively. The LODs ranged from 0.018 μg·L⁻¹ (for CHClBr₂) to 0.049 μg·L⁻¹ (for CHBr₃), being this technique the most sensitive one among those studied. Finally, after having optimized the sample preparation techniques and chromatographic conditions, several water samples were taken in two different water treatment plants in Spain (Zaragoza) and Colombia (Viterbo, Caldas). The results obtained are shown and discussed.     

Ecogeographical land characterization maps as a tool for assessing plant adaptation and their implications in agrobiodiversity studies

Information on plant adaptation can be very useful in agrobiodiversity studies. Ecogeographical land characterization (ELC) maps constitute a new tool in this direction with great potential. To assess the usefulness of this approach, an ELC map of Spain was created through multivariate methods. Its performance to characterize plant habitat preferences was compared with existing ecological regions and land cover maps. Collecting sites and seed weight from eight plant species were used to test the ELC map. Categories from each map were assigned to accessions using collecting sites. Chi-square tests were applied to test if category frequency distributions for each species followed a distribution proportional to the relative frequency of categories in each map. The tests found significant differences in the eight species studied. Thus, Bonferroni confidence intervals (BCI) classified categories from maps in preferred, neutral or avoided habitats. Seed weight was used as a proxy for plant adaptation. Comparison between observed and expected ranking of BCI and quartile classes in terms of seed weight means, and GLM and post-hoc tests carried out to test the effect of these classes upon seed weight showed consistently better results for the ELC map. Species results and applications of ecogeographic maps in plant genetic resources conservation are discussed.     

Is the variability in my crop due to genetic or environmental factors? Using heritability to solve this question

Journal of Crop Science and Biotechnology - Usually is common to see great differences among plants in our crops, this can allow us to think about selection of some plants with the best traits in...