Identification and characterization of a novel etiological agent of mango malformation disease in Mexico, Fusarium mexicanum sp. nov

The primary objective of this study was to characterize Fusarium spp. associated with the economically devastating mango malformation disease (MMD) in Mexico. In all, 142 Fusarium strains were isolated from symptomatic mango inflorescences and vegetative tissues in eight geographically diverse Mexican states from 2002 through 2007. Initially, all the Mexican isolates were screened for genetic diversity using appolymerase chain reaction and random amplified polymorphic DNA markers and were grouped into seven distinct genotypes. Based on results of these analyses, evolutionary relationships and species limits of the genetically diverse MMD-associated Fusarium spp. were investigated using multilocus DNA sequence data and phylogenetic species recognition. Maximum parsimony analyses of a five-locus data set comprising 5.8 kb of aligned DNA sequence data indicated that at least nine phylogenetically distinct Fusarium spp. within the Gibberella fujikuroi species complex are associated with MMD, including one species within the African clade (Fusarium pseudocircinatum), two species within the Asian clade (F. mangiferae and F. proliferatum), and at least six species within the American clade (F. sterilihyphosum and five undescribed Fusarium spp.). Molecular phylogenetic analyses indicate that a novel genealogically exclusive lineage within the American clade was the predominant MMD associate in Mexico. This new Fusarium sp. caused MMD and could be distinguished from all other known species morphologically by the production of mostly sterile, coiled hyphae which are typically associated with sporodochial conidiophores together with unbranched or sparsely branched aerial conidiophores. Koch's postulates were completed for isolates of the new species on nucellar seedlings of mango cv. Ataulfo. This pathogen is formally described herein as F. mexicanum.     

Effects of feeding frequency on growth,feed efficiency and body composition of juveniles Brazilian sardine,Sardinella brasiliensis (Steindacher 1879)

The Brazilian sardine is the most important fishery resource in Brazil. Their production has declined along the last 30 years due the overfishing, climatic and oceanographic phenomena. This study was carried out to determine the optimal feeding frequency for juvenile Brazilian sardine based on growth, feed efficiency, feed intake and body composition. Six feeding frequencies of one, two, three, four, five and six times a day were evaluated in triplicate tanks for 50 days. Fish with initial mean weight of 3.29 ± 0.56 g were fed daily to apparent satiation. The results showed that fish fed once daily had lower body weight gain, specific growth rate and condition factor (P < 0.05) compared with other treatments. The feed efficiency ratio in fish fed once daily was significantly higher (P < 0.05) than those fed two or more times a day. No significant differences were observed in the coefficient of variation in body weight (P > 0.05) among the treatments. Feed intake was directly proportional to the feeding frequency. Fish fed once daily showed lower hepatosomatic and mesenteric fat indices (P < 0.05) than the other treatments. Neither protein nor ash content of fish were significantly (P > 0.05) affected by feeding frequency. However, the lipid content increased with feeding frequency. The results suggest that the optimal feeding frequency for juvenile Brazilian sardine is at least twice daily.     

Comparison of isolated cranberry (Vaccinium macrocarpon Ait.) proanthocyanidins to catechin and procyanidins A2 and B2 for use as standards in the 4-(dimethylamino)cinnamaldehyde assay

The 4-(dimethylamino)cinnamaldehyde (DMAC) assay is currently used to quantify proanthocyanidin (PAC) content in cranberry products. However, this method suffers from issues of accuracy and precision in the analysis and comparison of PAC levels across a broad range of cranberry products. Current use of procyanidin A2 as a standard leads to an underestimation of PACs content in certain cranberry products, especially those containing higher molecular weight PACs. To begin to address the issue of accuracy, a method for the production of a cranberry PAC standard, derived from an extraction of cranberry (c-PAC) press cake, was developed and evaluated. Use of the c-PAC standard to quantify PAC content in cranberry samples resulted in values that were 2.2 times higher than those determined by procyanidin A2. Increased accuracy is critical for estimating PAC content in relationship to research on authenticity, efficacy, and bioactivity, especially in designing clinical trials for determination of putative health benefits.     

Simultaneous Removal of H2S, NH3, and Ethyl Mercaptan in Biotrickling Filters Packed with Poplar Wood and Polyurethane Foam: Impact of pH During Startup and Crossed Effects Evaluation

The present work discusses the startup and operation of different biotrickling filters during the simultaneous removal of NH₃, H₂S, and ethyl mercaptan (EM) for odor control, focusing on (a) the impact of pH control in the stability of the nitrification processes during reactor startup and (b) the crossed effects among selected pollutants and their by-products. Two biotrickling filters were packed with poplar wood chips (R1 and R2A), while a third reactor was packed with polyurethane foam (R2B). R2A and R2B presented a pH control system, whereas R1 did not. Loads of 2?C10?g N?CNH₃ m^?3?h^?1, 5?C16?g S?CH₂S m^?3?h^?1, and 1?C6?g EM m^?3?h^?1 were supplied to the bioreactors. The presence of a pH control loop in R2A and R2B proved to be crucial to avoid long startup periods and bioreactors malfunctioning due to biological activity inhibition. In addition, the impact of the presence of different concentrations of a series of N species (NH ₄ ⁺ , NO ₂ ^? , and NO ₃ ^? ) and S species (SO ₄ ^2? and S^2?) on the performance of the two biotrickling filters was studied by increasing their load to the reactors. Sulfide oxidation proved to be the most resilient process, since it was not affected in any of the experiments, while nitrification and EM removal were severely affected. In particular, the latter was affected by SO ₄ ^2? and NO ₂ ^? , while nitrification was significantly affected by NH ₄ ⁺ . The biotrickling filter packed with polyurethane foam was more sensitive to crossed effects than the biotrickling filter packed with poplar wood chips.     

Effect of the simultaneous interaction among ascorbic acid, iron and pH on the oxidative stability of oil-in-water emulsions

The objective of this study was to demonstrate how different factors can simultaneously influence the oxidative stability of an oil-in-water emulsion, and how these factors can be used to enlarge the variation range of oxidation markers, expressed as peroxide value (PV) and TBARS. Initially, a Plackett-Burman design was used to screen seven factors (temperature, pH, and iron, copper, ascorbyl palmitate, ascorbic acid, and sodium chloride concentrations). A temperature elevation of 30 to 60 °C reduced PV and TBARS, a pH change from 3.0 to 7.0 increased PV and reduced TBARS, and the presence of ascorbic acid (1 mmol/L) had no significant effect on PV but increased TBARS (p < 0.05). Thus, the temperature was fixed at 30 °C, and an emulsion was formulated with different combinations of ascorbic acid, iron, and pH according to a central composite rotatable design. Regression models were fitted to PV and TBARs responses and optimized to get the higher values of both markers of oxidation. The optimized emulsion contained 1.70 mmol/L AH (ascorbic acid) and 0.885 mmol/L FeSO(4) · 7H(2)O (1.0 mmol/L Fe(2+)) at pH 5.51 and 30 °C. The range of variation observed for oxidation markers in the optimized emulsion model (PV, 0-4.27 mequiv/L; TBARS, 0-13.55 mmol/L) was larger than the variation observed in the nonoptimized model (PV, 0-1.05 mequiv/L; TBARS, 0-1.00 mmol/L). The antioxidant activity of six compounds (Trolox, α-tocopherol, caffeic acid, gallic acid, catechin, and TBHQ) was evaluated using the optimized emulsion conditions. After application of the Tukey HSD post hoc statistical test, the samples that were not different (p < 0.05) in the nonoptimized emulsions showed a significant difference in the optimized emulsions. Considering the importance of the interactions on oxidation studies, our model represents a significant improvement in a direct methodology that can be applied to evaluate natural compounds under different combination of factors.     

Kinetics of thermal modifications in a grape seed extract

The thermal modification kinetics of a commercial grape seed extract (GSE) was investigated. A GSE was exposed to 60, 90, and 120 °C for 5, 10, 15, 30, 45, and 60 min. The antioxidant activity (AA) and the absorbance at 420 nm (A(420)) were measured. (+)-Catechin, (-)-epicatechin, procyanidins B1 and B2, and gallic acid were identified and measured. After the thermal treatments, the AA did not show a significant difference (p > 0.05) and both procyanidins and gallic acid increased as well as A(420). (+)-Catechin and (-)-epicatechin decreased. To obtain the activation energy (E(a)) of the changes, a modified Weibull and a combined zero- and first-order model were compared, both followed by the Arrhenius equation. The Weibull model was more accurate. The E(a) values for browning and (+)-catechin, (-)-epicatechin, gallic acid, and procyanidins B1 and B2 were 170, 286, 42, 102, 249, and 95 kJ/mol, respectively. The results were valid at a confident level of 95%.     

The effect of selected microbial strains on internal milieu of broiler chickens after peroral administration

The aim of this work was to investigate the effect of probiotic preparation with multi-strains composition (Lactobacillus delbrueckii ssp. bulgaricus LAT 187, Lactobacillus acidophilus LAT 180, Lactobacillus helveticus LAT 179, Lactobacillus delbrueckii ssp. lactis LAT 182, Streptococcus thermophilus LAT 205 and Enterococcus faecium E 253) on internal milieu, antioxidant status and body weight of broiler chickens. Chickens were divided into three groups (C, control; E1 and E2, experimental groups). Experimental chickens received the probiotic preparation in drinking water. Probiotic preparation caused a significant increase of serum calcium and potassium content. In the group with higher dose of probiotic strains serum triglycerides level decreased. Total antioxidant status in groups with addition of probiotic strains showed higher values in comparison to control group. Serum albumin level was found to increase after consumption of probiotic preparation in group with higher dose of probiotic strains. Probiotic strains improved body weight in last observed weeks of feeding.     

Performance and meat quality traits of beef heifers fed with two levels of concentrate and ruminally undegradable protein

The effects of two levels of concentrate and ruminally undegradable protein (RUP) on performance, intake, digestibility, carcass characteristics, meat quality traits, and commercial cuts yield were assessed. Twenty crossbred heifers (240 kg average body weight) were used. At the beginning of the trial, four animals were slaughtered as reference group and the 16 remaining animals were randomly assigned to four treatments, in a 2 × 2 factorial design: two levels of concentrate (40% and 80%, dry matter (DM) basis) and two levels of RUP (48.79% and 27.19% of CP). At the end of the trial, all the animals were slaughtered. There was no interaction (P > 0.05) between concentrate and RUP levels. Dry matter intake and nutrients digestibility was not affected (P > 0.05) by RUP level. Heifers fed the highest RUP level had greater (P < 0.05) average daily gain (ADG). Concentrate level did not affect (P > 0.05) DMI and ADG. Heifers fed diets with 80% concentrate had greater intake of TDN and EE, and lower intake of NDF (P < 0.05). The digestibilities of all nutrients, except the NDF, were greater (P < 0.05) for the 80% concentrate diets. The RUP levels did not affect (P > 0.05) the carcass characteristics and carcass gain composition. Heifers fed 80% concentrate diets had larger (P < 0.05) longissimus muscle area and lower gain of bones (P < 0.05). Concentrate level did not affect (P > 0.05) the composition of carcass gain. There was no effect (P > 0.05) of RUP and concentrate levels on meat quality traits and commercial cut yields.     

Resistance to cypermethrin, deltamethrin and chlorpyriphos in populations of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) from small farms of the State of São Paulo, Brazil

This study was undertaken to determine the flea diversity on urban dogs and cats in Australia in 2009-2010. A total of 2530 fleas were recovered from 291 animals (151 dogs, 69 cats and 71 uncategorised dogs or cats) from veterinary clinics across five states of Australia. The majority of specimens were from coastal areas. The cat flea (Ctenocephalides felis felis) was the most frequent flea species identified (98.8%, 2500/2530). The only other flea species identified was the stickfast flea (Echidnophaga gallinacea) from Western Australia. Sequencing of the cytochrome oxidase subunit II mtDNA revealed a single haplotype across Australia within a subset of C. f. felis (n=19). Our study demonstrated dominance and haplotype homogeneity of C. f. felis on dogs and cats. Although Ctenocephalides canis was recovered from a feral fox, it was not identified from the sample of fleas analysed. This suggests that, under current conditions, it is unlikely that foxes are reservoirs of C. canis for domestic dogs or cats residing in coastal Australia, as previously speculated.