Infectious disease serologic survey in free-ranging Venezuelan anacondas (Eunectes murinus).

Reptiles can harbor pathogenic microorganisms asymptomatically and serve as potential reservoirs of infection for humans, domestic animals, and other reptiles. Infectious diseases are also problematic for free-ranging reptile populations and are an important consideration in reptile reintroduction and translocation projects. There have been limited serologic studies of free-ranging reptiles for evidence of exposure to potential pathogens. In the present study, serum or plasma samples from five male and five female free-ranging Venezuelan anacondas (Eunectes murinus) were screened for antibodies to eastern, western, and Venezuelan equine encephalitis viruses, vesicular stomatitis virus, ophidian paramyxovirus, 19 Leptospira interrogans serovars, and Cryptosporidium serpentes. Antibodies to these agents were not detected, or antibody titers were low and possibly nonspecific. These results for the limited number of anacondas surveyed suggest that they do not serve as significant reservoirs for these infectious agents at this location.     

Genetic parameters for spawning and growth traits in the Pacific white shrimp (Penaeus (Litopenaeus) vannamei)

The aim of this study was to estimate genetic parameters for spawning traits and growth traits in a breeding line of Pacific white shrimp, Penaeus (Litopenaeus) vannamei, selected for growth and survival. Traits studied were number of eggs (NE) and number of nauplii (NN) and female body weight at insemination (FWI) and body weight at 130 days of age (BW130). Genetic parameters were estimated using a multivariate animal model. Heritability for NE and NN were estimated as 0.13 ± 0.04 and 0.03 ± 0.04 respectively. The contribution to NN total variation due to ‘factors associated with male’ effect was estimated as 0.47 ± 0.07. In the cases of FWI and BW130, heritability was estimated as 0.44 ± 0.08 and 0.19 ± 0.03 respectively. Genetic correlation between FWI and NE was estimated as 0.49 ± 0.15, between FWI and NN as 0.54 ± 0.39 and between NE and NN as 0.27 ± 0.41, whereas the genetic correlations of FWI, NE and NN with BW130 were 0.30 ± 0.13, ?0.21 ± 0.19 and ?0.25 ± 0.38 respectively. Although it is important to perform more studies on this issue, our results found no evidence of a genetic antagonistic effect between female reproductive traits and body weight at harvesting (130 days of age) in P. vannamei.     

Purification of xylitol obtained by fermentation of corncob hydrolysates

Hydrolysates obtained by autohydrolysis-posthydrolysis of corncobs were detoxified with charcoal, concentrated, supplemented with nutrients, and fermented with Debaryomyces hansenii. After biomass removal, the fermented media contained 0.1137 kg of nonvolatile components (NVC)/kg of liquor, which corresponded mainly to xylitol (0.6249 kg/kg of NVC) but also to minor amounts of inorganic components (measured as ashes), proteins, nonfermented sugars (xylose and arabinose), uronic acids, arabitol, and other nonvolatile components (ONVC). The media were subjected to further processing (sequential stages of adsorption, concentration, ethanol precipitation, concentration, and crystallization) to obtain food-grade xylitol. Adsorption experiments were carried out at various solid-to-liquor ratios. Under selected conditions (1 kg of charcoal/15 kg of liquors), the xylitol content increased to 0.6873 kg/kg of NVC, and almost total decoloration was achieved. The resulting liquor was concentrated by evaporation to increase its NVC content to 0.4032 kg/kg of liquor (corresponding to a xylitol concentration of 0.280 kg/kg of liquor), and ethanol was added to precipitate a part of the NVC (mainly proteins, but also uronic acids, ashes, and other nonvolatile compounds). Refined liquors (containing 0.7303 kg of xylitol/kg of NVC) were concentrated again, and ethanol was added (to reach 40-60% volume of the stream) to allow crystallization at -10 or -5 degrees C. Under selected conditions, 43.7% of xylitol contained in the initial fermentation broth was recovered in well-formed, homogeneous crystals, in which xylitol accounted for 98.9% of the total oven-dry weight. Material balances are presented for the whole processing scheme considered in this work.     

Bioprospection of Microalgae and Cyanobacteria as Biocontrol Agents Against Vibrio campbellii and Their Use in White Shrimp Litopenaeus vannamei Culture

Vibrio spp. are the most common and harmful shrimp pathogenic bacteria; however, microalgae and cyanobacteria have the ability to produce antimicrobial substances against these species. In this study, the organic and aqueous extracts of 28 species of marine microalgae and cyanobacteria were screened against Vibrio campbellii M1. Two of these phytoplankton species with antibacterial activity in aqueous extracts (Dunaliella tertiolecta and Skeletonema costatum) and nontoxic to brine shrimp Artemia franciscana nauplii were used to evaluate their anti‐Vibrio effect when used as green‐water cultures in Vibrio‐challenged white shrimp Litopenaeus vannamei cultures. No differences in mortality of juvenile L. vannamei were observed between treatments tested, suggesting that the pathogenicity of V. campbellii could be related to the growth stage of shrimp. The proximal composition of D. tertiolecta and S. costatum was in the recommended range for penaeid shrimp nutrition, allowing shrimp supplemented with these microalgae to have significantly greater total length and weight than control shrimp. Shrimp supplemented with S. costatum presented the highest values of organic mass (11.48 mg/organism) and growth rate (0.31 mg/d) in comparison to D. tertiolecta. These results indicate that microalgae are not only capable of producing antibacterial compounds against Vibrio but can also help shrimp nutrition.     

Changes in carotenoids and ABA content in Citrus leaves in response to girdling

The effect of girdling on abscisic acid, carotenoids content, xanthophylls cycle and non-photoquemical quenching was studied in leaves from different shoot types of containerized two-year-old ‘Loretina’ mandarin during spring flush period. Girdling increased abscisic acid in young leaves and decreased it in mature leaves. These changes were accompanied by a significant increase in leaf carotenoids, carotenoids:chlorophylls ratio, xanthophylls and xanthophylls cycle pool size and its de-epoxidation state in vegetative and multiflowered young leafy shoots. However, changes in de-epoxidation state did not correlate with the energy-dependent non-photochemical quenching. The role of carotenoids and abscisic acid as photoprotecting agents during the oxidative stress caused by girdling is discussed. In conclusion, this study provides evidence linking carotenoids-based photoprotecting mechanisms in the response to the stress induced by girdling in Citrus trees.     

Tartaric acid recovery from distilled lees and use of the residual solid as an economic nutrient for lactobacillus

The recovery of tartaric acid (TA) from distilled vinification lees coming from the white and red winemaking technology was optimized using response surface methodology and Statistica 5.0 software. The sequential treatment of dissolving TA and further calcium tartrate (CaT) precipitation could be used to recover up to 92.4% of the initial TA when distilled white lees were used. The residual lees were employed as economic nutrients for lactic acid production by Lactobacillus pentosus CECT-4023 using hemicellulosic vine shoot hydrolysates as carbon source. Distilled lees after TA extraction used as nutrients provided values of lactic acid (18.4-18.9 g/L), global volumetric productivities (0.82-0.84 g/L.h), and product yields (0.69-0.70 g/g) similar to those achieved when using the general medium for Lactobacilli (18.6 g/L, 1.11 g/L.h, and 0.62 g/g, respectively) or lees without TA extraction (16.4-17.2 g/L, 0.96-1.21 g/L.h, and 0.61-0.66 g/g, respectively). This technology not only avoids pollutant disposal but also represents a commercial source of tartaric acid and economic nutrients for biotechnological processes.     

Effects of intra-mammary bacterial infection with coagulase negative staphylococci and stage of lactation on shedding of epithelial cells and infiltration of leukocytes into milk: comparison among cows, goats and sheep

The effects of mammary gland bacterial infection and stage of lactation on leukocyte infiltration into the mammary gland were compared among cows, goats and sheep. Animals were at two stages of lactation: mid or late. In mid-lactation animals, bacterial-free glands and coagulase negative Staphylococcus (CNS)-infected glands were compared. In late lactation only uninfected glands were studied. Of mid-lactation bacteria-free animals, goats had the highest number of leukocytes and % polymorphonuclears (PMNs), whereas sheep had the lowest and leukocytes number in cows were intermediate between sheep and goats. Based on %PMN, two cell clusters were found in sheep, which overlapped with the parallel cell clusters of cows and goats, but with a slightly higher number of leukocytes in each cell cluster. At late lactation, goats had higher values for %PMN and leukocyte numbers in comparison to cows, which had a similar cellular profile to sheep. The cellular immune response to CNS infection was similar for the three animal species, although the number of cells was different, while the basal cell level at mid-lactation and especially at the end of lactation was species specific.     

Simultaneous Extraction and Depolymerization of Fucoidan from Sargassum muticum in Aqueous Media

The biomass components of the invasive seaweed Sargassum muticum were fractionated to allow their separate valorization. S. muticum (Sm) and the solid residue remaining after alginate extraction of this seaweed (AESm) were processed with hot, compressed water (hydrothermal processing) to assess the effects of temperature on fucoidan solubilization. Fucose-containing oligosaccharides were identified as reaction products. Operating under optimal conditions (170 °C), up to 62 and 85 wt% of the dry mass of Sm and AESm were solubilized, respectively. The reaction media were subjected to precipitation, nanofiltration and freeze-drying. The dried products contained 50% and 85% of the fucoidan present in Sm and AESm, respectively; together with other components such as phenolics and inorganic components. The saccharidic fraction, accounting for up to 35% of the dried extracts, contained fucose as the main sugar, and also galactose, xylose, glucose and mannose. The concentrates were characterized for antioxidant activity using the TEAC assay.     

Effect of dietary protein content on growth rate,survival and body composition of juvenile cauque river prawn,Macrobrachium americanum (Bate 1868)

We determined the effect of four concentrations of dietary crude protein, 30.7, 37.2, 41.8 and 46.8% on growth rate, survival and body composition of the juvenile cauque river prawn (Macrobrachium americanum). The prawns were hatched in the laboratory from the spawn of one wild ovigerous female. Prawns consuming 37.2% crude protein reached a final weight of 0.58 g (feed conversion ratio of 2.15), which was significantly better than the other treatments. Survival was 100% in all treatments. Protein content in the diets had no significant effect on whole body proximate composition and amino acid profile. Juveniles consuming the 37.2% crude protein diet grew faster than those fed the other diets. Specific growth rate was adjusted to the two‐slope broken‐line regression analysis model to estimate the optimal protein requirement. In conclusion, these results demonstrated that the 37.2% protein level diet is optimal for juvenile cauque river prawn M. americanum in the experimental conditions of this study.     

Susceptibility of Caligus rogercresseyi collected from the native fish species Eleginops maclovinus (Cuvier) to antiparasitics applied by immersion

A major challenge for Chilean salmon farming is infestation by the ectoparasite Caligus rogercresseyi. In addition, there is evidence that a loss of chemotherapeutic treatment efficacy against important fish pathogens is occurring in salmon farming, including antiparasitic efficacy. Currently, there are known techniques that allow the determination of the susceptibility profile of parasites to antiparasitic treatment. However, there is scarce information about both threshold values and categorization of antiparasitic susceptibility for C. rogercresseyi. Bioassay technique allowed the determination of both mean values and the natural variation of EC50%, which were contrasted with available susceptibility thresholds. Results allowed to determine that parasites from the native fish host, Eleginops maclovinus, are susceptible to azamethiphos, deltamethrin and cypermethrin treatments, showing a high susceptibility profile to antiparasitics.