Benefits of using the probiotic Efinol®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz), in the Amazon

The objective of this experiment was to test the probiotic Efinol^®L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz). For the transportation, fish were distributed in 18 plastic tanks, of which nine contained the Efinol^®L (10 mg L⁻¹; probiotic treatment) and the remaining had no probiotic (control treatment). Transport lasted 24 h and three different boxes of each treatment were sampled at 3, 12 and 24 h. Up to the 12-h sampling period, no significant difference in the survival was observed; on the other hand, survival was higher at the end of the transport (24 h) in the probiotic treatment. No significant difference was found in dissolved oxygen and temperature between treatments. Conductivity, pH and alkalinity increased along the transport, but without a difference between treatments. Ammonia increased in all treatments, although it was significantly lower in the probiotic group at 24 h. Cortisol levels were significantly higher in all transported fish when compared with the basal values. At 24 h, cortisol levels in control fish were significantly higher than those in the probiotic treatment. With the observed results, we are able to conclude that the probiotic Efinol^®L is efficient during cardinal transport, lowering the mortality and helping maintain water quality possibly by lowering metabolic wastes.     

Synthesis and insecticidal activity of new amide derivatives of piperine

The natural lipophilic amides piperine and piperiline were isolated from Piper nigrum L (Piperaceae). Piperine was hydrolysed into piperic acid (85% yield) which was converted into 16 amides (28–89% yield). The contact toxicity of all synthetic amides, and also that of piperine and piperiline, at the dose 10 µg per insect, was evaluated for the Brazilian economically important insects Ascia monuste orseis Latr, Acanthoscelides obtectus Say, Brevicoryne brassicae L, Protopolybia exigua DeSaus and Cornitermes cumulans Kollar. The results demontrated that the insects have different sensivities to the various amides, with mortality ranging from 0 to 97.5% according to the compound and insect species. © 2000 Society of Chemical Industry     

Orange peel fragment improves antioxidant capacity and haematological profile of Nile tilapia subjected to heat/dissolved oxygen‐induced stress

This study evaluated the ability of orange peel fragment (OPF) to act as a functional feedstuff, influencing growth, haematological profile, and antioxidant enzyme activity of Nile tilapia subjected heat/dissolved oxygen‐induced stress (HDOIS). A group of 440 male Nile tilapia (31.7 g ± 0.34) was randomly distributed in 40 250‐L aquaria (11 fish/tank) and fed five practical diets with graded levels of OPF at 0%, 0.2%, 0.4%, 0.6%, and 0.8% for 70 days. The diets were formulated to contain 30% crude protein and 18 MJ/kg crude energy. After the feeding period, growth performance was evaluated and six fish per treatment were sampled for haematological profile and antioxidant enzyme activity, before and after HDOIS. Then, fish were subjected to HDOIS (32°C/2.3 mg/L dissolved oxygen) for three days and the same haematological profile and antioxidant enzyme activity were determined. There was no effect of OPF on the haematological profile, either before or after HDOIS. The polynomial regression model was used to express the relationship between antioxidant enzymes activity and OPF supplementation level. The maximum activity of superoxide dismutase, catalase, and glutathione peroxidase was reached at 0.66%, 0.63%, and 0.68% of OPF respectively. Results of the present study suggest that a dietary supplementation level of 0.63%–0.68% of orange peel fragment was appropriate to maintain Nile tilapia haematological profile and improve its antioxidant capacity under HDOIS.     

Dietary organic acids blend alone or in combination with an essential oil on the survival,growth, gut/liver structure and de hemato‐immunological in Nile tilapia Oreochromis niloticus

This study evaluated the effects of dietary supplementation of organic acids blend (OAB) alone or in combination with essential oil, Lippia origanoides (OAE) for Nile tilapia fed supplemented diets for 30 days. Fish (1.1 ± 0.04 g) were fed control (Control), or OAB 0.5% or OAB 0.5% + essential oil 0.125% (OAE) respectively. At the end of the experiment, samples were collected for de hemato‐immunological, histological analysis of the intestine and liver, as well as microbiology of the intestine. The pH of the diets supplemented with OAB and OAE reduced 0.92 and 0.19 respectively. The growth and FCR were unaffected by the treatments, but survival was significantly higher in the OAB treatment. Fish fed the OAB diet showed reduced concentration of total heterotrophic bacteria and Pseudomonas sp. in the intestine. Increased glucose in fish fed OAB and high number of circulating monocytes in fish fed OAE diet were observed. The anterior intestine of fish fed OAE diet showed larger number of goblet cells and increased villi height. The diet supplemented with OAB, mainly, improved the intestinal health and survival of tilapia juveniles and can be used in juvenile production.     

Effects of an Enterococcus faecium‐based probiotic on growth performance and health of Pirarucu,Arapaima gigas

Intensive fish farming has resulted in an increased concern for disease outbreaks. Probiotic use is one of the strategies being developed to improve fish health and productivity. Measures of probiotic colonization, growth performance, haematological characteristics and parasite load were used to evaluate the effect of diets supplemented with Enterococcus faecium on growth and health of Arapaima gigas juveniles. A completely randomized design with four treatments (diet with E. faecium at 1 × 10⁶ CFU/g and 1 × 10⁸ CFU/g, control diet and diet with the culture medium MRS) and three replicates was used. Ninety‐six Arapaima juveniles were distributed in 12 cages fed with the specified diet for 68 days. Colonization of the intestinal tract by lactic acid bacteria reduced the total number of heterotrophic bacteria in fish fed with probiotics compared to controls. Fish fed a supplemented diet containing 1 × 10⁸ CFU/g presented higher values of weight gain, survival and fish growth uniformity, and lower values of feed conversion ratio. The prevalence of Trichodina sp. could have affected the survival of fish in the control group. Reduction in parasite load and an increase in haematocrit, the number of erythrocytes, thrombocytes, neutrophils and monocytes were also observed in fish fed the diet containing 1 × 10⁸ CFU/g. Enterococcus faecium presented a probiotic effect in A. gigas juveniles and can be recommended for use at a concentration of 1 × 10⁸ CFU/g to modify the gut microbiota, improve growth performance and haematology and reduce parasitic load.     

Molecular and comparative mapping for heading date and plant height in oat

Selection of oat genotypes combining earliness and short plant height could stimulate oat cultivation worldwide. However, the mechanisms involved with the genetic control of heading date and plant height traits are not fully understood to date. This study aimed to identify genomic regions controlling heading date and plant height in two hulled by naked oat populations and to compare these genomic regions with that of other grass species. Recombinant inbred lines of each population and their parents were genotyped by a 6 K BeadChip Illumina Infinium array and assessed for heading date and plant height in two sowing dates. The quantitative trait loci (QTL) affecting these traits were detected by simple interval mapping. The two oat populations showed different genetic mechanisms controlling heading date. A major QTL was identified in one of the populations, mapped into the ‘Mrg33’ consensus linkage group from the current oat map. Two other QTL were detected into the ‘Mrg02’ and ‘Mrg24’ groups, in the second population. On the other hand, both populations presented the same genomic region controlling plant height. Six SNP markers, mapping on the same linkage group within each population, were associated with the trait, regardless the sowing date, explaining more than 20% of the phenotypic variation. Five of these six markers were mapped into three different linkage groups on the oat consensus map. Genomic regions associated with heading date and plant height in oat seem to be conserved in Oryza sativa L. and Brachypodium distachyon. Our results provide valuable information for marker-assisted selection in oats, allowing selection for earliness and plant height on early segregating generations.     

Surface liming effects on soil radiation attenuation properties

Purpose

This study investigates the effects of surface liming on soil attenuation radiation properties. For this, measurements of soil chemical attributes (pH, organic carbon, H+Al, Al³⁺, Ca²⁺, and Mg²⁺) and attenuation radiation parameters (mass attenuation coefficient, μ_m, atomic and electronic cross sections, σ_a and σ_e, effective atomic number and electron density, Z_eff and N_el) were carried out. This aim was motivated by the fact that possible μ_m variation might cause as well variation in the determination of soil physical properties.

Materials and methods

The studied soil, classified as a Dystrudept sity-clay, is located in South Brazil. The trial consisted of five stripes, one of them under pasture and the remaining under no-till system (NTS). Lime rates of 0, 10, 15, and 20 t ha^?1 were broadcast on the NTS soil surface. Disturbed soil samples were collected 30 months after liming at the top (0–10 cm) and subsoil (10–20 cm) layers. Soil chemical attributes were characterized following standard experimental procedures. The soil oxide composition, obtained by EDXRF analysis, was used to calculate μ_m for ²⁴¹Am and ¹³⁷Cs photon energies with XCOM computer code. μ_m values were employed to calculate σ_a, σ_e, Z_eff, and N_el and to predict variations in soil bulk density (ρ) and total porosity (φ).

Results and discussion

Surface liming notably increased contents of soil pH, Ca²⁺, and Mg²⁺ while reduced H+Al and Al³⁺ at the top soil layer, where μ_m, σ_a, σ_e, and Z_eff were also increased with the lime rates. However, at the subsoil layer, liming neither lessened soil acidity nor induced remarkable changes in the attenuation parameters. When using ¹³⁷Cs photon energy, incoherent scattering totally dominated over the radiation interaction processes whereas photoelectric absorption and coherent scattering substantially contributed when ²⁴¹Am photon energy was used. Therefore, the increasing in soil attenuation parameters at the top soil layer was more accentuated considering ²⁴¹Am than ¹³⁷Cs photon energy. Variation in μ_m caused considerable variation in ρ and φ only for ²⁴¹Am photon energy.

Conclusions

The findings regarding the effect of μ_m variation induced by liming on the determination of soil physical properties are extremely relevant because traditionally, in the soil science area, μ_m values are calculated without considering any chemical modification to which the soil can be submitted. Bearing in mind that ρ and φ are important parameters from the agricultural and environmental points of view, not representative measurements of μ_m can lead to biased values of ρ and φ.

     

Chemical Characterization and Release of Polyphenols from Pecan Nut Shell [<Emphasis Type="Italic">Carya illinoinensis</Emphasis> (Wangenh) C. Koch] in Zein Microparticles for Bioactive Applications

The pecan nut [Carya illinoinensis (Wangenh) C. Koch] is a natural source of polyphenols with antioxidant properties. In this study, the encapsulation of aqueous and hydroalcoholic extracts of pecan nut shell were evaluated for the release of bioactive compounds and antioxidant potential in order to explore food applications using zein as encapsulating agent. The extracts showed high contents of total phenolics, condensed tannins and high antioxidant activity. Concentrations of proanthocyanidins were 9-fold higher in hydroalcoholic extracts. The LC-DAD analysis showed that catechins were the major phenolic compounds in samples, with epigallocatechin levels up to 138.62 mg mL^?1. Zein microparticles loaded with aqueous extract released 2.3 times more phenolic compounds than the hydroalcoholic extracts and the DSC thermograms showed that extracts of pecan nut shell remained thermally stable up to 240 °C. The zein microcapsules obtained in this study were efficiently encapsulated and represent an interesting additive due its high antioxidant capacity, physicochemical characteristics and morphology. The use of zein microparticles combined with natural extracts constitute a step forward in the improvement of current technology for delivering phenolic compounds with applications in functional foods and nutraceuticals.     

Digestive enzyme activity in the intestine of Nile tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis> L.) under pond and cage farming systems

The effect of different farming systems (cage, pond) upon digestive enzyme activities of Nile tilapia was evaluated. Juvenile Nile tilapia (87.61 ± 1.52 g) were simultaneously cultured in pond and cage systems during 90 days. Cages used nutritional biphasic plan (35 and 32 % crude protein—CP feeds) and ponds used nutritional triphasic plan (35, 32 and 28 % CP feeds). Biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the performance of enzyme activities. Total proteolytic, amylase and lipase activities were not statistically different between the treatments throughout the periods analyzed (31, 63 and 94 days of culture). However, trypsin and chymotrypsin activities were higher with 31 and 63 days of culture in fish from pond system, suggesting that natural food may have influenced these activities. A positive correlation was observed between the recommended concentration of essential amino acids for Nile tilapia and specific aminopeptidases activity in fish cage system. Substrate–SDS–PAGE revealed 12 active proteolytic bands in both systems. However, integrated density (ID) values were higher in the bands of ponds. Specimens of either cage or pond exhibited five bands of amylolytic activity. Fish from cage and pond systems showed the highest values of ID within 31 days of cultivation. In this study, the complexity of digestive functions could be verified for animals maintained under commercial conditions. Some of the assessed enzymes may show adaptations of their activities and/or expression that allow the fish to achieve a more efficient nutrient assimilation.