Nuevo artículo de investigación BIOLAB

Volume 83, September 2019, Pages 1-8, Journal of Stored Products Research

Degradation of gluten proteins by Fusariumspecies and their impact on the grain quality of bread wheat


Francisco Javier BellesiAgustín Francisco ArataMauro MartínezAdriana Cecilia ArrigoniSebastián Alberto Stenglein y María Inés Dinolfo

Highlights

•Degradation kinetic of storage proteins depends on the incubation period.
•Different Fusarium species can affect negatively the gluten strength.
•Different responses could be related to subunits composition of wheat genotypes.

 

 

Abstract

The protein quality of wheat, the most important crop worldwide, is affected by the presence of fungi, mainly those belonging to the Fusarium genus. The aim of this study is to analyze the effects of Fusarium spp. on ground wheat grains quality by measuring gluten strength and quantifying the gliadin/glutenin content. A total of 23 Fusarium spp. isolates and two bread wheat (Triticum aestivum L.) genotypes with contrasting baking quality were used in the investigation. The results of SDS sedimentation test (SDSS) revealed that the presence of Fusarium species significantly affected the gluten strength negatively; while F. pseudograminearum and F. graminearum are the species that predominantly affected the SDSS values. Principal component analysis of gluten composition showed that the effect of Fusarium species on gluten composition depended on the wheat genotypes analyzed. Cluster analysis revealed that all the Fusarium species used as inoculum produced severe effects on grain quality and gluten composition on both the genotypes. In summary, our results showed that the presence of Fusarium spp. impaired storage proteins affecting the wheat dough properties. Therefore, constant monitoring is necessary to reduce the presence of Fusarium in the food chain for reducing the negative potential impact on bread quality.

Acceso al artículo:
https://www.sciencedirect.com/science/article/pii/S0022474X19300608

Nuevo artículo de investigación GENEBSO

Ground Beetles in a Changing World: Communities in a Modified Wetland Landscape

  • A S Nanni
  • N G Fracassi
  • A L Magnano
  • A C Cicchino
  • R D Quintana

Abstract

Wetlands are being increasingly affected by anthropogenic activities worldwide. The Lower Delta of the Paraná River, one of the most important wetlands in Argentina, has been profoundly altered because most of the natural environments were drained or diked to make them suitable for different agricultural activities. As a result, the landscape is characterized by a mosaic of Salicaceae afforestations of different ages interspersed with patches of secondary forests and grazing grasslands. The high susceptibility of Carabidae and Aphodiidae to natural and human-induced disturbances and management practices is reflected by changes in their spatiotemporal distribution. We performed a 1-year study to analyze and compare beetle’s communities inhabiting different habitat types in this modified wetland landscape. A total of 58 beetle species were recorded, of which 48 were carabids and 10 aphodids. Although species richness and diversity were higher in productive habitats (afforestations and grasslands) than in secondary forests, hydrophilic species were only found in the latter. Community parameters varied seasonally. Our results indicate a close relationship between wetland beetle communities and vegetation cover in each habitat type. Human activity increases heterogeneity across this landscape, which favors the colonization of new species but causes the loss or displacement of autochthonous species. The secondary forests could serve as alternative habitats for beetles typical of humid environments. We propose the maintenance of the current heterogeneous mosaic to favor the diversity of ground beetles and the implementation of changes in water management for the benefit of hydrophilic beetle species.

Keywords

Carabidae Aphodiidae habitat type secondary forests hydrophilic beetle 

 
Ground Beetles in a Changing World

Registro de Sclerotium rolfsii como causante de pudrición de corona y raíces de Pseudogynoxis benthamii

Revista Mexicana de Biodiversidad. Vol. 89, núm. 3 (2018)

Registro de Sclerotium rolfsii como causante de pudrición de corona y raíces de Pseudogynoxis benthamii

New host record of Sclerotium rolfsii causing crown and root rot on Pseudogynoxis benthamii

 

Marta C. Rivera

Eduardo R. Wright

Luciana Silvestro

Sebastián Stenglein

Adriana Kato

En marzo de 2016, de un total de 40 plantas de Pseudogynoxis benthamii cultivadas en Buenos Aires, Argentina, se observó marchitez en 10 de ellas. El objetivo de este trabajo fue identificar el agente causal de la enfermedad. Se obtuvieron 5 aislados fúngicos de características similares a partir de esclerocios desarrollados sobre las raíces, de los cuales se seleccionó 1, que luego de ser inoculado en plantas sanas, causó síntomas en un período de 2 semanas. El patógeno fue identificado como Sclerotium rolfsii sobre la base de sus características morfológicas. Se amplificó y secuenció la región de la espaciadora interna transcrita de ADN ribosomal del núcleo del aislado. El análisis de ADN mostró 99-100% de similitud para S. rolfsii. Este es el primer reporte de S. rolfsii como agente causal de marchitez en P. benthamii y el primer patógeno citado sobre esta especie en el mundo.

Effect of matching microalgal strains origin and regional weather condition on biomass productivity in environmental photobioreactors

Effect of matching microalgal strains origin and regional weather condition on biomass productivity in environmental photobioreactors

Highlights
• Twenty-six microalgal strains were isolated from a high irradiance geographical site.
• Biochemical characterization of the biomass suggested technological potential.
• Pioneering studies on modeling microalgal productivity in South America
• Productivity under extreme environmental conditions agreed with strains origin.
• An exotic strain outperformed a native one under mean weather conditions.

 

Abstract

It is generally assumed that increased microalgal biomass productivity on any particular geographical site would be most likely achieved by strains native to that region. However, direct assessment of that hypothesis remains challenging. Here we isolated and biochemically characterized twenty-six microalgal strains from one of the regions with the highest irradiances of the planet. Biomass and lipids productivity of phylogenetically-close Scenedesmus strains native to regions of contrasting irradiances performed similarly under laboratory culture conditions. Culture simulations in environmental photobioreactors, mimicking regional weather conditions, broadly showed physiological responses of these strains according to their origin. However, under the mean weather conditions of a predicted highly productive region, an exotic strain from a lower irradiance zone resulted 40% more productive than a phylogenetically close-relative native strain. These results challenge the generalized view of the convenience of using native microalgae to increase productivity and broadens the discussion towards alternative scenarios.

Keywords

Microalgae
Bioprospecting
High irradiance
Scenedesmus spp.
Biomass productivity
Environmental photobioreactor
 

A photophysical and spectroelectrochemical study on n-phenyl-carbazoles and their oxidized species

Artículo Ramirez 2018

Cristina Luján Ramírez

María Inés Mangione

Sonia Graciela Bertolotti

Ernesto Maximiliano Arbeloa

Alejandro Rubén Parise

Highlights

•Ground and singlet excited states of N-phenyl-carbazoles were characterized.
•Properties of dicarbazoles are susceptible to electronic coupling between single units.
•The oxidized species were analyzed by cyclic voltammetry and spectroelectrochemistry.
•An electrochromic polymer was deposited by electropolymerization.
•The studied compounds might be suitable as fluorescent sensors and hole transporters.

Abstract

A series of N-phenyl-carbazole derivatives namely TCz (N-tolyl-carbazol), TCz-TCz (a 3,3´-linked dimer), and CzPh-CH2-PhCz (a methylene-bridged N-phenyl-carbazole), have been synthesized and studied by means of absorption and fluorescence spectra, DFT calculations, cyclic voltammetry and spectroelectrochemistry. It is concluded that the methylene bridge in CzPh-CH2-PhCz isolates the two TCz units, whereas TCz-TCz allows extending the electronic coupling along both carbazoles. Moreover, the phosphorescence spectrum of TCz-TCz showed a high energy triplet state (2.61 eV). It was observed that oxidation of CzPh-CH2-PhCz generates an electrochromic polymer containing TCz-TCz dimer units separated by methylene bridges. Oxidized TCz-TCz subunit was analyzed by EPR spectroscopy, and found to be a Class III mixed valence ion in Robin and Day classification. All results suggest that these molecules might be suitable as selective probes in fluorescence sensing or as host materials in electroluminescent devices.

https://doi.org/10.1016/j.jphotochem.2018.07.039