Development of a method for the genetic identification of mussel species belonging to Mytilus, Perna, Aulacomya, and other genera

Legislation regarding the labeling of processed products is an important issue in the protection of consumer rights. This labeling is especially important in products that cannot be identified on the basis of their morphological characters, because these are removed from the animal in the transformation process. The goal of this study was the identification of mussel species using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Forensically Informative Nucleotide Sequencing (FINS) methodologies. The molecular marker selected was 18S rDNA (nuclear small-subunit rDNA gene), which allows identification at the genus level and at the species level in some cases. The genera included in this study were Mytilus, Perna, Aulacomya, Semimytilus, Brachidontes, Choromytilus, and Perumytilus. Different markers were used for genetic identification at the species level. To identify the species included in the genus Perna and Choromytilus, a fragment of ITS 1 (Internal Transcribed Spacer 1) was amplified by multiplex PCR and digested with restrictases. The species of Mytilus were identified by length polymorphism and RFLP of the polyphenolic adhesive protein gene. This methodology was validated with products manufactured in the authors' pilot plant and applied to commercial samples. Therefore, this sequential method can be completely or partially used to determine the mussel genus or species present in any food product.     

Resistance monitoring of Heliothis virescens to pyramided cotton varieties with a hydrateable, artificial cotton leaf bioassay

Proof of concept was demonstrated for a practical, off-the-shelf bioassay to monitor for tobacco budworm resistance to pyramided Bt cotton using plant filtrates. The bioassay was based on a previously described feeding disruption test using hydrateable artificial diet containing a blue indicator dye, a diagnostic dose of insecticide and novel assay architecture. Using neonate larvae from a Bt-susceptible, laboratory reared tobacco budworm strain, a diagnostic dose for Bollgard II and WideStrike cotton was obtained that limited neonate blue fecal production to 0-2 pellets in 24 h (Bt-resistant larvae produced >2 fecal pellets). The bioassay was tested with three different field populations of tobacco budworm collected from tobacco in central North Carolina (USA) and shown to accurately diagnose susceptibility to Bt. The diagnostic doses were also successfully evaluated with two Bt-resistant, laboratory reared tobacco budworm strains. Shelf life studies showed the assay could be stored for at least 6 months at room temperature (longer storage times were not studied). The application of the bioassay as an easy to use monitoring tool is discussed.     

Mutants in the lipopolysaccharide of Brucella ovis are attenuated and protect against B. ovis infection in mice

Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis.     

Trichoderma as a biological agent of Fusarium oxysporum species complex and Vigna unguiculata growth promoter

European Journal of Plant Pathology - This study aimed to evaluate the potential antagonistic role of Trichoderma in the control of Fusarium isolates belonging to the Fusarium oxysporum species...     

Differences in body temperature, cell viability, and HSP-70 concentrations between Pelibuey and Suffolk sheep under heat stress

Pelibuey and Suffolk sheep were compared as to their capacity to regulate body temperature under environmental hyperthermia by measuring their differences in cellular response to heat stress (HS). In a first experiment, seven Pelibuey and seven Suffolk ewes were kept in a climatic chamber for 6 h daily during 10 days (temperatures within the 18 to 39.5 °C range). As chamber temperature rose, sheep rectal temperature increased in both groups, but to a lesser extent in Pelibuey (0.3 °C) than in Suffolk sheep (0.7 °C) (P?<?0.05). In a second experiment, cellular viability was assessed using cultured blood mononuclear cells from 15 Pelibuey and 15 Suffolk sheep. They were incubated at 37 °C for 24 h (control) or 43 °C for 6 h followed by 18 h at 37 °C (HS). In a third experiment, another blood mononuclear cells culture from eight Pelibuey and eight Suffolk sheep was kept at 37 °C for 15 h; these were subsequently cultured for 6 h at 37 °C (controls) or 43 °C (HS). Next, HSP-70 concentration was determined. HS reduced the percentage of viable cells to a greater extent in Suffolk [37 °C (73.7 %) vs. 43 °C (61.9 %); P?<?0.05] than in Pelibuey sheep [37 °C (74.9 %) vs. 43 °C (66.7 %); P?>?0.05]. HS significantly increased HSP-70 average concentrations for both breeds at 43 °C. A significant effect was observed for the breed by temperature interaction (P?<?0.05) caused by a greater difference between Pelibuey and Suffolk at 43 °C (2.85 vs. 0.53 ng/mL, respectively; P?<?0.05) than at 37 °C (0.05 vs. 0.03 ng/mL, respectively; P?>?0.05). In conclusion, Pelibuey sheep show more effective body temperature regulation under conditions of environmental hyperthermia. Also, cell viability after HS was higher in Pelibuey than in Suffolk, an effect that could be mediated by an HSP-70-related mechanism.     

Improved <Emphasis Type="Italic">S</Emphasis>-genotyping and new incompatibility groups in Japanese plum

The selection of cross-compatible cultivars is essential to ensure fruit set in self-incompatible species like Japanese plum and thus the S-genotype must be determined in order to establish incompatibility groups. In this study an improved Japanese plum S-genotyping method, based in polymerase chain reaction and capillary electrophoresis detection of intron polymorphisms of S-locus genes, S-RNase and SFB, has been assayed and validated in a wide sample of cultivars. This method allows a more precise determination of amplified fragment sizes and therefore a better differentiation of self-incompatibility alleles. The assayed methodology was proven effective in the detection of 13 different S-alleles of S-RNases and SFBs and was used to S-genotype 105 Japanese plum cultivars, 32 of which are described by first time in this work. Analysed cultivars were assigned into 11 incompatibility groups and two new incompatibility groups (XX and XXI) were identified, increasing to 21 the number of incompatibility groups described in this crop.     

Full-Scale Remediation of a Jet Fuel-Contaminated Soil: Assessment of Biodegradation, Volatilization, and Bioavailability

Here, we addressed biodegradation vs. volatilization processes, and also bioavailability limitations during biopile remediation of soil initially contaminated by more than 5,000 mg/kg of hydrocarbons. In order to select bioremediation strategies, we first conducted a biotreatability study, which included geochemical, textural, and microbiological characterization of the soil matrix. Next, we implemented five bioremediation approaches onsite in real-scale biopiles. In order to monitor hydrocarbon depletion and to distinguish between biological and non-biological processes, we analyzed chemical biomarkers by means of gas chromatography?Cmass spectrometry. In addition, a comprehensive study of soil grain size and its implications on bioavailability were studied. Furthermore, the evolution of microbial populations was also examined. Two of the strategies implemented in the biopiles (the combination of a slow-release fertilizer and a surfactant, and the use of an oleophilic fertilizer respectively) reduced the soil hydrocarbon content to under 500 mg/kg in 5 months. Additional results from this study indicate that volatilization was the predominant degradation process for light hydrocarbons (below 12 carbon atoms), whereas heavier compounds were mainly biodegraded. However, even in the most favorable situation, a residual concentration of hydrocarbons linked to the finer fraction of the soil was found.     

Growth,Feed Utilization,and Glycemic Response in European Sea Bass,Dicentrarchus labrax,Juveniles Fed Carbohydrate of Different Complexities

The effect of dietary carbohydrate complexity on growth, feed utilization, and glycemia was studied in European sea bass juveniles. Four isonitrogenous (50% crude protein) and isolipidic (15% crude lipids) diets were formulated to contain 20% pregelatinized maize starch (PGS diet), dextrin (DEX diet), maltose (MAL diet), or glucose (GLU diet). No effect of dietary carbohydrate complexity on growth was noticed. Feed efficiency and protein efficiency ratio were lower in fish fed the GLU diet than in the other groups, whereas the opposite was observed for feed intake. Plasma glucose peaked 3–4 h after feeding in fish fed the MAL and GLU diets, whereas in fish fed the PGS and DEX diets the peak was reached 5–6 h after feeding. Peak plasma glucose concentration (13 mmol/L) was higher in fish fed the GLU diet than the other diets (9 mmol/L). Shorter hyperglycemia duration was observed in fish fed the MALT and GLU diets (6 h) than the PGS and DEX diets (10 h). Complex carbohydrates delayed plasma glucose concentration peak compared with simple sugars, whereas the opposite was observed for hyperglycemia duration. Overall, dietary maltose, dextrin, and starch were apparently better utilized as energy source than glucose by European sea bass juveniles.     

Effect of chitosan-based edible coatings applied by vacuum impregnation on quality preservation of fresh-cut carrot

Edible coatings based on high molecular weight chitosan, pure or combined with methylcellulose or oleic acid, were applied to fresh-cut carrots cv. Nantesa by simple immersion and by applying a vacuum pulse (5 kPa for 4 min). Water vapour resistance, colour, mechanical properties and respiration rates of non-coated and coated samples were determined. Coatings improved sample appearance, since they diminished the occurrence of the white blush during storage. When applied by simple immersion, they neither conferred significant barrier properties nor the preservation of the mechanical properties of fresh-cut carrot samples. In contrast, coating application with a vacuum pulse enhanced all the positive effects, since the resistance of water vapour transmission of the samples was significantly improved, and better preservation of the sample colour and mechanical response during cold storage was obtained. Differences in film composition did not significantly affect the coating behaviour, probably due to the variability induced by different factors when coatings were applied to the carrot surface.