A Comparative Study on Removal Efficiency of Cr(VI) in Aqueous Solution by <Emphasis Type="Italic">Fusarium</Emphasis> sp. and <Emphasis Type="Italic">Myrothecium</Emphasis> sp.

Environmental pollution with chromium is due to residues of several industrial processes. Bioremediation is an alternative actually considered to remove Cr (VI) from the environment, using adapted organisms that grow in contaminated places. Have been conducted studies with fungi mechanisms of interaction with chromium, most of which have focused on processes biosorption, characterized it by passive binding of metal components of the cell surface, and bioaccumulation, wherein the metal entry to cells occurs with energy expenditure. The paper presents the results of studies carried out on sorption of chromium (VI) ions from aqueous solutions by Fusarium sp. and Myrothecium sp. Both biomasses have the ability to take up hexavalent chromium during the stationary phase of growth and as well inactive conditions. Fusarium sp. showed 26% of biosorption with active biomass and 64% in inactive biomass; meanwhile, Myrothecium sp. obtained 97 and 82%, respectively. Both fungi showed adjust to pseudo-second-order model in active (Fusarium sp. R ² = 0.99; Myrothecium sp. R ² = 0.96) and inactive biomass assay (Fusarium sp. R ² = 0.99; Myrothecium sp. R ² = 0.99). The data of the active biomass test also confirmed to the intraparticle diffusion model (Fusarium sp. R ² = 0.98; Myrothecium sp. R ² = 0.93). The results obtained through this investigation indicate the possibility of treating waste effluents containing hexavalent chromium using Fusarium sp. and Myrothecium sp.     

Alternatives to regular urea for abating N losses in lettuce production under sub-tropical climate

Alternative fertilization practices are needed for reducing gaseous and leaching N losses at high urea application rates. The objective of this study was to compare gaseous N emissions (N₂O and NH₃) and NO₃ ^? concentrations in the soil solution during two successive lettuce cropping seasons under contrasting fertilization practices. Treatments were fertilization with regular urea (U), urea treated with urease [N-(n-butyl) thiophosphoric triamide (NBPT)] and nitrification [dicyandiamide (DCD)] inhibitors (UIs), non-acidified pig slurry compost (PSC), acidified pig slurry compost (APSC), and an unfertilized control (C). Acidification of pig slurry during composting had no impact on soil cumulative N₂O emissions during the cropping seasons. The use of composts resulted in emission factors (EFs) (PSC, 0.09% of applied N; APSC, 0.16%) an order of magnitude smaller than with regular urea (1.63%). Similarly, adding NBPT and DCD to urea reduced the N₂O EF from 1.63 to 0.37% of applied N and fertilizer-induced NH₃ emissions from 30.2 to 3.4% of applied N. Composts and UI resulted in yield-scaled N₂O emissions that were 33 to 49% lower than the unfertilized control and 64 to 73% lower than the regular urea estimates, indicating a greater efficiency of supplied N with composts and UI. Nitrate concentration of the soil solution (at 0.1 and 0.3 m) in PSC, APSC, and UI plots was similar to the control and up to 17 times lower than with regular urea, indicating reduced risks for leaching losses. We conclude that, as compared to regular urea, the use of composted pig slurry, with and without acidification, and the addition of NBPT and DCD inhibitors to urea are good practices to reduce environmental N losses from lettuce production under sub-tropical climate.     

Live-weight gains of Holstein × Zebu heifers grazing a <Emphasis Type="Italic">Cratylia argentea</Emphasis>/Toledo-grass (<Emphasis Type="Italic">Brachiaria brizantha</Emphasis>) association in the Mexican humid tropics

The legume Cratylia argentea associated to Brachiaria brizantha—Toledo-grass (Bb + Ca) and Toledo-grass alone (Bb) were evaluated under grazing conditions by Holstein × Zebu heifers. Three evaluation periods during three consecutive years, were performed. We measured, daily live-weight gains of heifers (DWG, g/day); biomass dry matter (BDM, kg/ha) at beginning and end of each grazing period. On plant samples, were measured percentages of crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, in situ DM degradability (ISDMD), and voluntary biomass DM intake (VBI, g/LW^0.75) using the Cr₂O₃/in situ indigestibility technique. A completely randomized design was applied, using heifers as experimental units for DWG gains and VBI. At the beginning of the grazing, the BDM for Bb + Ca and Bb–considering the three periods-averaged, 3065 and 936 kg/ha, respectively. Crude protein content of C. argentea was around 20 %; and for Bb + Ca or Bb, ranged from 8.7 to 4.6 %. In either treatment, in situ DM degradability averaged 72.6 % (P ≥ 0.05), regardless of the botanical component type. Biomass DM intake was 83.02 (Bb + Ca) and 89.22 (Bb) g/LW^0.75. The DWG gains (g/heifer) for Bb + Ca and Bb were (per period): 829 and 574 (first); 469 and 118 (second); and 534 and 508 (third). This study showed that the Bb + Ca association was better to improve the daily gain of F1 Holstein × Zebu heifers, as compared to Bb alone. Also, C. argentea associated to a low to medium-quality grass improved the nutritional value of the diet without affecting the biomass DM intake.     

Cell Wall Reinforcement in the Potato Tuber Periderm After Crop Treatment with Potassium Phosphite

The potato periderm is the outer tissue of potato tubers that protects the tuber from pathogen attack, dehydration, and wounding during harvest and storage. It is of secondary origin and replaces the epidermis early during tuber development. The outer layers of the periderm consist of cells with suberized walls. Phosphite compounds (Phi) are inorganic salts from phosphorous acid, and in previous works, we demonstrated that they are effective in protecting potato plants from biotic stress caused by different pathogens and also against UV-B radiation. The aim of the present work was to study the effect of Phi on the post-harvest potato periderm structure, cell wall components, and related enzymes. In three years of field experiments, potassium phosphite (KPhi) applications were compared with an untreated control. KPhi was applied to seed tubers before planting combined with foliage application of a conventional fungicide, to seed tubers and foliage without conventional fungicide, or to seed tubers combined with foliage application of KPhi plus a conventional fungicide. Observations of periderm sections showed increases in suberin and pectin depositions in post-harvest tubers from KPhi-treated plants compared to tubers from non-treated plants. In addition, peroxidase activity increased in the periderm tissue. The activity of laccases and superoxide dismutase was measured in the protein extract of the periderm, and an increase due to KPhi treatment was detected. The results presented here suggest that early KPhi treatment to seed tubers followed by foliage treatment leads to reinforcement of the cell wall of periderm cells, which represents a benefit for future response to stresses.     

Implications of the Red Beet Ripening on the Colour and Betalain Composition Relationships

The evolution during ripening of Beta vulgaris (var. Pablo) on colour and betalain composition, not previously conducted in conjunction in red beets, has been examined. According to the results, it could be asserted that the ripening stage significantly (p?<?0.05) influenced on all the studied parameters. On the basis of the betalain content, the optimum ripening stage corresponded to a medium weigh-to-calibre ratio, in the light of the significantly (p?<?0.05) higher content of betalains, especially betanin and vulgaxanthin I. Moreover, colour attributes also differed during ripening, having the medium-ripened beetroots a significantly (p?<?0.05) more reddish hue (h_ab) and lower lightness (L*), probably due to the higher content of betaxanthins in this stage. The colour differences among red beets in the stage II and the rest of stages were visually appreciable (ΔE*_ab?>?3) and mainly qualitative. A new range of opportunities for diversification of colorant market, from a nutritional and colorimetric point of view, could be possible by employing red beets with different stages of ripening.     

<Emphasis Type="Italic">t</Emphasis>-Resveratrol Protects against Acute High Glucose Damage in Endothelial Cells

Postprandial hyperglycemia in diabetic and nondiabetic subjects is associated with endothelial dysfunction. Evidence shows that high glucose generates oxidative stress and a pro-inflammatory state promoting the development of cardiovascular diseases. trans-Resveratrol (t-RV) has been shown to reduce cardiovascular risk. To determine whether t-RV acts as a protector against acute high glucose (AHG)-induced damage, two in vitro models, rat aortic rings (RAR) and human umbilical vein endothelial cells (HUVEC) were used. RAR pretreated with AHG (25 mM D-glucose) for 3 h dramatically decreased the endothelium-dependent relaxation (EDR) induced by acetylcholine in phenylephrine (PE)-precontracted vessels. However, coincubation with t-RV significantly mitigated the damage induced by AHG on EDR. Pretreatment with AHG did not affect the vasodilation induced by sodium nitroprusside. HUVEC treated with t-RV decreased cytotoxicity and reduced radical oxygen species production induced by AHG. Taken together, these results suggest that t-RV can mitigate the AHG-induced EDR damage through a mechanism involving ROS scavenging and probably an increase in the bioavailability of NO.     

Effect of pearl millet silage ammoniated with urea on lamb production and metabolic performance

The objective of this study was to determine the effect of diets containing pearl millet silage ammoniated with urea on the intake, digestibility, production performance, and nitrogen metabolism of lambs. Thirty‐two uncastrated mixed‐breed lambs at 4 to 5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight replicates. Experimental diets consisted of pearl millet silage ammoniated with urea during ensiling at the levels of 0, 20, 40, and 60 g/kg dry matter (DM). Increasing urea levels in the pearl millet silage led to a linear decrease (p < .05) in the intakes of DM, organic matter, and total digestible nutrients by the lambs. Total and average daily weight gains decreased linearly (p < .05) with the addition of urea to the silage. Intake and digestibility of crude protein, nitrogen intake, urine urea nitrogen, plasma urea nitrogen, microbial synthesis, and microbial efficiency had a quadratic response (p < .05) to the urea levels in the silage. Pearl millet silage ammoniated with urea reduces dry‐matter intake and daily weight gain in lambs. Urea is not recommended for use in the ensiling of pearl millet.     

Lambari fish Deuterodon iguape as an alternative to live bait for estuarine recreational fishing

Fishing tourism is growing steadily in Brazil. Artisanal fishers meeting the demand for recreational fishing are capturing live juvenile shrimp in the estuaries and selling them for live bait, preventing the recruitment of a larger contingent into the ocean. This study compares the efficiency of using lambari, Deuterodon iguape Eigenmann, as live bait with the shrimp, Penaeus schmitti Burkenroad, while fishing for common snook (Centropomus spp.), as well as to evaluate the swimming behaviour of D. iguape in different salinities. The results showed that there was no significant difference between the live baits used (P. schmitti vs D. iguape). The month, the period of the day and salinity presented differences. The size of the species did not depend on the type of bait used. There was no statistical difference in swimming behaviour, but there was a trend of increased speed and displacement in the group exposed to a salinity of 10 g/L. In conclusion, D. iguape appears as effective as P. schmitti and can be successfully used as live bait; and from an ecological point of view, it reduces the impact of fishing on juvenile shrimp.     

Influence of porosity of low-density polyethylene media on the maturation process of biofilters used in recirculating aquaculture systems

The effect of pores with different diameters in polyethylene media on the process of ammonia nitrification during the maturation of biofilters is evaluated. Four types of media were produced: M1 without pores, M2 with 40–112 μm in diameter pores, M3 with 125–187 μm diameter pores, and M4 with 312–437 μm diameter pores. Ammonia concentrations were statistically equal among media. On the majority of days, nitrite concentrations were lowest for M1 and M2, intermediate for M3, and highest for M4. Increased pore diameter favored the formation of biofilm in the interior, but the pores obtained in the expansion process were not interconnected, which may have caused low oxygenation of the water in the internal area. It was concluded that porosity did not reduce biofiltration time and did not increase the efficiency of nitrification of ammonia.     

Response of juvenile Norway​ spruce (Picea abies [L.] Karst.) to ectomycorrhizal inoculation of perlite-peat substrates in a nursery

Nursery growth substrate and ectomycorrhizal symbiosis are important circumstances influencing seedling development. In this study, the effect of pre-sowing inoculation of pure peat and peat+perlite mixtures (2:1 and 1:1, v:v) with an ectomycorrhizal mycelium-bead inoculum prepared in the laboratory and commercial inoculum Ectovit on ectomycorrhiza formation, growth, and foliar nutrients concentration of 1-year-old bare-root Norway spruce seedlings was estimated. Seedlings grown in the substrates inoculated with bead inoculum had significantly larger shoot dry weight and slightly higher other growth parameters than those grown in non-inoculated and Ectovit-inoculated substrates. However, the use of inocula formed neither treatment-specific ectomycorrhizal morphotypes nor higher mycorrhization of roots compared to control. Ectomycorrhizae were most probably formed by naturally occurring fungi; nevertheless, based on the abundance of the morphotypes, any participation of the applied fungi in ectomycorrhiza formation and/or their non-nutritional effects is not excluded. Seedlings grown in peat+perlite (2:1) mixture were slightly higher-developed than those in the two other substrates, but significant effect of the substrates neither on seedling growth nor on ectomycorrhiza formation was detected. In all treatments, sufficient macroelements concentration in needles was found. The results suggest difficulties to reach a complex positive effect of ectomycorrhizal inoculation in operational conditions and its dependence on various circumstances.