Correction to: Search for reservoirs of ‘Candidatus Liberibacter solanacearum’ and mollicutes in weeds associated with carrot and celery crops

European Journal of Plant Pathology -     

An in vivo map of the yeast protein interactome

Protein interactions regulate the systems-level behavior of cells; thus, deciphering the structure and dynamics of protein interaction networks in their cellular context is a central goal in biology. We have performed a genome-wide in vivo screen for protein-protein interactions in Saccharomyces cerevisiae by means of a protein-fragment complementation assay (PCA). We identified 2770 interactions among 1124 endogenously expressed proteins. Comparison with previous studies confirmed known interactions, but most were not known, revealing a previously unexplored subspace of the yeast protein interactome. The PCA detected structural and topological relationships between proteins, providing an 8-nanometer-resolution map of dynamically interacting complexes in vivo and extended networks that provide insights into fundamental cellular processes, including cell polarization and autophagy, pathways that are evolutionarily conserved and central to both development and human health.     

Composition of the water-soluble fraction of different cheeses

Volatile and nonvolatile compounds present in the water-soluble fraction (WSF) and water-soluble fraction with molecular weight lower than 1000 Da (WSF < 1000 Da) of six Spanish cheeses, Cabrales, Idiazábal, Mahón, Manchego, Roncal, and a goat's milk cheese, were analyzed. Different nitrogen fractions (determined by Kjeldahl method), caseins (by capillary electrophoresis), peptides and amino acids (by HPLC), and volatile components (by dynamic headspace coupled to GC-MS) as well as mineral content in the cheese fractions were analyzed and compared. The different nitrogen and volatile compounds identified in the WSF were characteristic of each cheese variety. Cabrales cheese displayed the highest content of free amino acids and the highest quantity and variety of volatile compounds. The WSF < 1000 Da fraction was less representative, especially for volatile compounds, as some of the components were lost in the ultrafiltration. Alcohols were better recovered than ketones and esters.     

Use of near-infrared spectroscopy for screening the individual and total glucosinolate contents in Indian mustard seed (Brassica juncea L. Czern. & Coss.)

The potential of near-infrared spectroscopy (NIRS) for screening the sinigrin, gluconapin, 4-hydroxyglucobrassicin, and total glucosinolate contents of Indian mustard (Brassica juncea L. Czern. & Coss.) seed was assessed. Intact seed samples of this species were analyzed by NIRS and their reference values regressed against different spectral transformations by modified partial least-squares (MPLS) regression. The coefficients of determination (r (2)) for sinigrin, gluconapin, 4-hydroxyglucobrassicin, and total glucosinolate contents were, respectively, 0.86, 0.95, 0.33, and 0.82. The standard deviation to standard error of prediction (SEP) ratio, and SEP to standard error of laboratory ratio were for these constituents as follows: sinigrin, 2.59 and 2.70; gluconapin, 4.16 and 2.08; 4-hydroxyglucobrassicin, 1.18 and 1.40; and total glucosinolates, 2.18 and 1.60. By comparison of commercial sinigrin spectrum with the first MPLS loadings of the sinigrin equation, it can be concluded that the molecule of sinigrin has a specific signal in the seed spectrum of Brassica.     

Rapid determination of mercury in food colorants using electrothermal atomic absorption spectrometry with slurry sample introduction

The determination of mercury in different types of color food additives using electrothermal atomic absorption spectrometry is proposed. The procedure involves direct introduction of the additive samples as suspensions, and fast-program methodology is used to avoid mercury volatilization losses. Suspensions are prepared in a medium containing 0.1% w/v Triton X-100, 1% v/v concentrated nitric acid, 2% w/v potassium permanganate, and 3% w/v silver nitrate before being directly introduced into the furnace. Calibration uses aqueous standards, and compensation of the background is carried out using the Zeeman device. The characteristic mass is 61 pg and the detection limit is 59 pg. The reliability of the procedure is checked by comparing the results obtained with other results based on microwave-oven sample digestion, and by analyzing a certified reference material.     

Basis for a new procedure to eliminate diarrheic shellfish toxins from a contaminated matrix.

The natural contamination of shellfish with diarrheic shellfish toxins (DSP) has important public health implications. To avoid the economic effects of toxic episodes on shellfish farmers and the related industry, research on artificial methods alternative to the natural detoxification of shellfish is needed. Because the usual thermal processes are not efficient, alternative technologies have to be studied. Here preliminary results are presented about the lability of the DSP toxin okadaic acid in a supercritical atmosphere of carbon dioxide with acetic acid. Most of the toxin is eliminated (up to 90%), and the biological activity against its target enzyme is also severely affected (up to 70% reduction). Detoxification of contaminated shellfish requires a partial dehydration, and the detoxification yield is lower than that obtained with free toxin. Mass spectrometry experiments suggest that acetylation of the toxin molecule is not the basis of the inactivating mechanism, but a conformational change is suggested. This is the first report of the use of supercritical fluids to inactivate toxins.     

Decomposition of cattle manure and colonization by macroinvertebrates in sediment of a wetland of the Middle Paraná River

Purpose

The study was carried out in a wetland of the Middle Paraná River system, Argentina, in order to evaluate the processes associated with the decomposition of manure, which includes changes in chemical composition, nutrient release of manure, and colonization of invertebrates. We also compared the invertebrate assemblage that colonized manure with that present in the benthos of the wetland.

Materials and methods

Nylon bags were filled with fresh cattle manure and anchored to the littoral zone of the wetland. Six bags were collected after 1, 2, 6, 14, 21, 28, 33, 55, and 79 days: three for invertebrate determination and the other three bags for determination of dry mass and chemical analyses. The nutrient content, cellulose, lignin, and total phenolic compounds of manure were determined. In addition, the leachate of manure was collected for nutrient analyses. Samples of the wetland benthic sediment were collected for benthic invertebrate determination and particle size analyses. Spearman rank correlation was used to evaluate the relationship between chemical compounds of manure and breakdown rate. Principal component analysis was used to explore invertebrate assemblage composition of manure and sediment during the experiment.

Results and discussion

Limnodrilus, Dero, and Chironomus were dominant in the manure. Gatherer-collector was the dominant group in the manure, comprising almost 95 % of the total density of invertebrates. Breakdown rate was significantly related with nutrients, cellulose and total phenolics of manure. An ordination plot showed changes in invertebrate assemblages of manure and sediment samples over time.

Conclusions

This study provides new insight on the importance of manure as a substrate for macroinvertebrate colonization. Cattle manure needs to be considered as a potential source of nutrients for aquatic systems and a substrate for invertebrate assemblages.

     

Variation of favism-inducing factors (vicine,convicine and L-DOPA) during pod development inVicia faba L.

Changes in the concentrations of vicine, convicine and L-DOPA in two cultivars ofVicia faba L. seeds in different stages of pod development were determined by high performance liquid chromatography (HPLC). The vicine and convincine conent was highest in fresh green cotyledons (moisture content about 80%) and gradually declined until a constant level was reached when seed dry matter percentage was around 40%. A similar pattern of variation in glucoside concentration was observed for the seed coat. The pods contained neither vicine nor convicine but they were particularly rich in L-DOPA. These compounds were not homogeneously distributed in the seeds.