Exploring the Diversity of Red Microalgae for Exopolysaccharide Production

Microalgae constitute a remarkable biological diversity but a limited number of them have been the object of study for their ability to produce exoplysaccharides (EPS). Among them, the red marine microalgae Porphyridium or Rhodella produce sulphated EPS, exhibiting some biological activities with potential interest in the pharmaceutical and cosmetic industries. EPS from Porphyridium and Rhodella being relatively similar in their composition, it has long been considered that all the red microalgae produced similar EPS and no attention was paid to other red microalgae. The objective of our work was then to explore the diversity of red microalgae for the production of EPS, focusing in this first step on the screening of the strains for their ability to produce EPS and preliminary structural characterization. The study was conducted with 11 microalgae strains belonging to the proteorhodophytina subphylum. All microalgae were able to produce EPS, released in the culture medium (strains belonging to Porphyridiophyceae and Rhodellophyceae classes) or remaining bound to the cells (strains from Stylonematophyceae class). The analysis of monosaccharides composition was found significantly different, with for instance high levels of glucuronic acids in the EPS from C. japonica and N. cyanea, but also strong differences in the sulphation degrees of polymers (between 1.2 and 28.7% eq. SO4)

Relación entre los niveles séricos de colesterol y glucosa ante y posparto con la presencia de trastornos reproductivos durante el puerperio en vacas lecheras en Zamorano

15 p.Borjas, A. 2004. Relación entre los niveles séricos de colesterol y glucosa ante y posparto con la presencia de trastornos reproductivos durante el puerperio en vacas lecheras en Zamorano. Proyecto Especial del Programa de Ingeniero Agrónomo, Zamorano, Honduras. 15 p. Los niveles de glucosa y colesterol se relacionan con el nivel y movilización de energía del animal, lo cual puede afectar a la vaca negativamente en su desempeño reproductivo. El objetivo del estudio fue determinar la relación entre los valores séricos de colesterol y glucosa ante y posparto y los trastornos reproductivos durante la etapa del puerperio en vacas lecheras. La investigación se realizó entre octubre de 2003 a agosto de 2004 en Zamorano, Honduras. Se utilizaron 14 vacas multíparas y se utilizó un diseño completamente al azar con medidas repetidas en el tiempo, cada vaca fue una unidad experimental. La relación de colesterol alto anteparto con retención de placenta fue de r =-0.71; P =0.17, y catarro genital r =-0.11; P =0.85. Colesterol bajo posparto con retención de placenta fue de r =-0.15; P =0.68, catarro genital r =-0.6; P =0.08 y piómetra de r =-0.15; P =0.68. El nivel alto de glucosa anteparto con la retención de placenta fue de r =-0.43; P =0.13, con catarro genital r =0.12; P =0.67 y piómetra r =0.18; P =0.54. Los niveles altos de glucosa posparto con retención de placenta fue de r =-0.48; P =0.18 y con catarro genital r =0.55; P =0.11. Los niveles bajos de glucosa posparto con la retención de placenta fue de r =-0.73; P =0.26, con catarro genital r =0.73; P =0.26 y piómetra r =-0.34; P =0.65. La dispersión de los datos pudo deberse a la poca cantidad de animales estudiados. Se concluye que bajo las condiciones de este estudio no se encontró correlación entre los valores séricos ante y posparto de glucosa y colesterol con los trastornos reproductivos en el parto y periparto

Evaluation of the impact of the wheat straw quality for bio-based construction materials: raw materials under drought and high CO2 uptake

International audienc

Exploring the Diversity of Red Microalgae for Exopolysaccharide Production

International audienceMicroalgae constitute a remarkable biological diversity but a limited number of them have been the object of study for their ability to produce exoplysaccharides (EPS). Among them, the red marine microalgae Porphyridium or Rhodella produce sulphated EPS, exhibiting some biological activities with potential interest in the pharmaceutical and cosmetic industries. EPS from Porphyridium and Rhodella being relatively similar in their composition, it has long been considered that all the red microalgae produced similar EPS and no attention was paid to other red microalgae. The objective of our work was then to explore the diversity of red microalgae for the production of EPS, focusing in this first step on the screening of the strains for their ability to produce EPS and preliminary structural characterization. The study was conducted with 11 microalgae strains belonging to the proteorhodophytina subphylum. All microalgae were able to produce EPS, released in the culture medium (strains belonging to Porphyridiophyceae and Rhodellophyceae classes) or remaining bound to the cells (strains from Stylonematophyceae class). The analysis of monosaccharides composition was found significantly different, with for instance high levels of glucuronic acids in the EPS from C. japonica and N. cyanea, but also strong differences in the sulphation degrees of polymers (between 1.2 and 28.7% eq. SO4)

Multifunctional polysaccharides bioformulations to enhance wheat (Triticum aestivum) adaptation to environmental stress condition.

International audienceCurrent needs in Sustainable Agricultural Systems require the decrease of conventional pesticides and fertilizers. Nowadays, biomolecules are associated with a newly form of agricultural practices that could reduce the use of agrochemical products and ensure plant adaptation to environmental stress conditions such as drought and thermal stress. For example, polysaccharides from algae (alginate) and mushrooms (chitosan) can be used as a microcarriers, providing diverse active molecules like macro- or micro-nutrients, polymers and oligomers which are known to enhance plant adaptation in response to different stress. Indeed, they are known to induce the production of Pathogenesis Related proteins (PR proteins), which stimulate plant defense mechanisms, forewarning against biotic stress and are involved in plant signalization of abiotic stress. In addition, they have a capacity to reticulate with ionic crosslinkers like phosphates and calcium salts to trap water molecules which would have a role in the cell ionic equilibrium. Conceptually, a multifunctional biostimulation can occur in the plant in synergy through polysaccharides, ions and water inputs. Our project aims at generating natural polysaccharidic bioformulations and evaluating their potential effect on wheat tolerance under water and thermal stress at different scales. Firstly, molecular and physiological analyses will be carried out under controlled conditions in order to determine the suitable applications and concentrations of bioactive molecules. Then, using semi controlled platform dedicated to wheat phenotyping under different water regimes (Pheno3C, UMR GDEC-INRAE Crouël, France), experiments will be performed to validate the effect of the bioformulations under natural field conditions. Finally, some of the most promising bioformulated products will be tested in field using farmers’ trials under the supervision of the Agricultural French Cooperative Oxyane. In parallel, total fungi biomass and seed storage proteins of treated plots will be estimated to determine the effect of the bioformulations on the rhizosphere composition and the migrations of nutrients during grain maturation

Exploring Novel Applications for Hydrogels Derived from Modified Celluloses

The valorization of lignocellulosic biomass by-products holds significant economic and ecological potential, considering their global overproduction. This paper introduces the fabrication of a novel wheat-straw-based hydrogel and a new microcellulose-based hydrogel through 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) oxidation. In this study, Fourier transform infrared (FTIR) analysis was employed for the detection of carboxyl groups, neutralization titration was conducted using a conductivity meter, viscosity analysis was performed using a rheometer, and transmittance analysis was carried out using a spectrophotometer. Two novel hydrogels based on TEMPO oxidation have been developed. Among them, the bio-based hydrogel derived from oxidized wheat straw exhibited exceptional printability and injectability. We found that the oxidation degree of microcellulose reached 56–69%, and the oxidation degree of wheat straw reached 56–63%. The cross-linking of 4% oxidized wheat straw and calcium chloride was completed in 400 seconds, and the viscosity exceeded 100,000 Pa·s. In summary, we have successfully created low-cost hydrogels through the modification of wheat straw and microcellulose, transforming lignocellulosic biomass by-products into a sustainable source of polymers. This paper verifies the future applicability of biomass materials in 3D printing

Exploring Novel Applications for Hydrogels Derived from Modified Celluloses

International audienceThe valorization of lignocellulosic biomass by-products holds significant economic and ecological potential, considering their global overproduction. This paper introduces the fabrication of a novel wheat-straw-based hydrogel and a new microcellulose-based hydrogel through 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) oxidation. In this study, Fourier transform infrared (FTIR) analysis was employed for the detection of carboxyl groups, neutralization titration was conducted using a conductivity meter, viscosity analysis was performed using a rheometer, and transmittance analysis was carried out using a spectrophotometer. Two novel hydrogels based on TEMPO oxidation have been developed. Among them, the bio-based hydrogel derived from oxidized wheat straw exhibited exceptional printability and injectability. We found that the oxidation degree of microcellulose reached 56–69%, and the oxidation degree of wheat straw reached 56–63%. The cross-linking of 4% oxidized wheat straw and calcium chloride was completed in 400 seconds, and the viscosity exceeded 100,000 Pa·s. In summary, we have successfully created low-cost hydrogels through the modification of wheat straw and microcellulose, transforming lignocellulosic biomass by-products into a sustainable source of polymers. This paper verifies the future applicability of biomass materials in 3D printing

Unfolded protein response in cereals, a dynamic signaling pathway involved in response to environmental stresses

International audienceStress of the endoplasmic reticulum (ER) is induced by the accumulation of misfolded proteins in this organelle. It can be triggered by biotic and abiotic stress (particularly heat), but also by chemical treatments (such as DTT and tunicamycin) at a laboratory scale. To respond to this stress, various cellular mechanisms are involved, including the highly conserved protein repair pathway, the UPR (Unfolded Protein Response). This pathway aims to restore protein homeostasis in cells. In cereals, seed storage proteins (SSP) represent one of the characteristics that determine grain quality and are of great interest to agri culture. Unlike dicots, the dynamics of the UPR induction pathway in monocots are poorly documented in the literature. In this review, in addition to the different mechanisms involved in the protein homeostasis maintenance in response to ER stress in cereals, orthologs of UPR induction’s markers have been identified. A focus has been made on the dynamics of the UPR pathway in seedlings and in seeds under chemical UPR inducers (DTT and tunicamycine) and heat stress. The interac tions between the different actors of the UPR pathway are also reviewed and discussed