Comprehensive proteomic analysis of camel milk-derived extracellular vesicles

Extracellular vesicles were recovered by optimized density gradient ultracentrifugation from milk of Camelus (C.) dromedarius, C. bactrianus and hybrids reared in Kazakhstan, visualized by transmission electron microscopy and characterized by nanoparticle tracking analysis. Purified extracellular vesicles had a heterogeneous size distribution with diameters varying between 25 and 170 nm, with average yield of 9.49 x 108 - 4.18 x 1010 particles per milliliter of milk. Using a comprehensive strategy combining classical and advanced proteomic approaches an extensive LC-MS/MS proteomic analysis was performed of EVs purified from 24 camel milks (C. bactrianus, n=8, C. dromedarius, n=10, and hybrids, n=6). A total of 1,010 unique proteins involved in different biological processes were thus identified, including most of the markers associated with small extracellular vesicles, such as CD9, CD63, CD81, HSP70, HSP90, TSG101 and ADAM10. Camel milk-derived EV proteins were classified according to biological processes, cellular components and molecular functions using gene-GO term enrichment analysis of DAVID 6.8 bioinformatics resource. Camel milk-derived EVs were mostly enriched with exosomal proteins. The most prevalent biological processes of camel milk-derived EV proteins were associated with exosome synthesis and its secretion processes (such as intracellular protein transport, translation, cell-cell adhesion and protein transport, and translational initiation) and were mostly engaged in molecular functions such as Poly(A) RNA and ATP binding, protein binding and structural constituent of ribosome. Proteomic studies of camel milk and sub-fractions thereof, such as casein, whey, or the milk fat globule membrane (MFGM) have revealed a plethora of bioactive proteins and peptides beneficial for developing immune and metabolic systems (Casado et al., 2008; Kussmann and Van Bladeren, 2011). By contrast, camel milk-derived EVs are still a largely uncharted proteomic terrain, although we know that milk-derived EVs carry cell origin-specific cargo and transport both bioactivity and information between cells (de la Torre Gomez et al., 2018)

Comparative effect of organic and inorganic selenium supplementation on selenium status in camel

AbstractSelenium deficiency is widely described in livestock from the Arabian Peninsula, notably in the camel, and selenium supplementation is based on cattle or horse requirements, usually with sodium selenite product. In order to test the effect of organic Se supplementation vs inorganic Se, 24 pregnant camels were subjected to 3 treatment groups starting one month before delivery (control without Se, non-organic bolus, organic Se). Blood, milk and feces samples were collected from one month before delivery to 3months of lactation. At delivery, the organic group had a significant higher Se concentration (P<0.01) in serum (8.21±1.38μg/100mL) and in colostrum (7.27±2.89μg/100mL) than in inorganic group (3.90±0.68 and 3.72±0.71, respectively) and than in control group (5.45±2.38 and 2.70±0.66, respectively). In calf serum, the Se concentration was significantly higher (P<0.001) in the two supplemented groups (6.32±2.81 and 5.99±3.31μg/100mL in organic and inorganic groups, respectively) than in control (3.42±1.41μg/100mL). The Se in mother serum decreased after parturition but was highly correlated to Se serum in calf and to Se fecal excretion. Se in milk was lower than in colostrum in all groups (P<0.01). Treatments had no significant effect on somatic cell count. This study revealed that organic supplementation in camel appeared more efficient

Manufacture and characterization of white cheese from camel milk: Mineralisation and buffering capacity- A comparaison with cow milk.

Camel milk is consumed as raw milk or after pasteurization. An other possible valorisation of camel milk is to transform it in cheese. In this work, white cheese from camel milk was manufactured and physico-chemically characterized. A same protocol was used to make the same cheese with cow milk previously standardized to have the same concentrations in fat (~20 g/kg) and total nitrogen (~25 g/kg) contents than those of camel milk. Milks and cheeses were characterized with special attentions paid on their rates of acidification (for milks) and for their mineralization and buffering capacity during chemical alkalinisation (for cheeses). Recoveries of protein and fat were also calculated for cheeses manufactured with both milks. The rates of acidification were very different for both milks because the final pHs were reached at 5 and 18h for cow and camel milks, respectively. The recovery of protein in the cheese was better for camel milk (~84%).than those determined for cow milk (~73%) although that the recovery of fat was better for cow milk than camel milk (~68 and ~57%’ respectively). On the other hand, cheeses manufactured with camel milk were more mineralized in calcium than those made with cow milk. Concerning the buffering capacity, maximal buffering capacities were determined at pH close to 6.0 for both cheeses. It was noted a second maximal peaks at pH 4.0 for cow milk but not for camel milk. All these results will be discussed in relation with our knowledge on cow milk and also by taking into account the special composition and organisation of camel milk

Au-Rh and Au-Pd Nanoalloys supported on well-defined Rutile Titania Nanorods for Aromatics Hydrogenation Applications

International @ RAFFINAGE+GBE:PAF:LPIInternational audienceTuning the composition of bimetallic catalysts as well as controlling their interaction with oxide supports are critical in order to control catalytic properties for hydrogenation and oxidation reactions. In this respect, a tremendous work has been made in recent years to prepare Au-based bimetallic catalysts due to the enhancement of catalytic properties when combining Au with noble metals in nanoalloys [1]. However, up to now, while Au-Pd systems have been widely studied mainly for oxidation reactions, Au-Rh nanoalloys have been rarely envisaged [2, 3]. Similarly, the nature of the interaction between these bimetallic systems and oxide supports is not well understood due to the poorly defined morphology of most of the oxides used. Therefore, using well-defined oxide supports offers opportunities to simplify the nature of the bimetallic particles support interaction. The objective of the present study was to prepare Au-M (M = Rh, Pd) bimetallic systems by comparing the efficiency of colloidal or impregnation techniques for obtaining nanoalloys with fine tuning of their composition. These Au-M bimetallic systems were supported on TiO2 nanorods to provide catalytic systems with well-defined metal-support interaction for in-depth HRTEM characterization. Rutile nanorods were obtained first by peptization under acidic conditions using HClO4 and hydrous titania as precursor. Second, a hydrothermal treatment was performed at 200°C for 48 h under strong acidic conditions (pH = 0.8) in the presence of a shape controlling agent, MgSO4, in order to obtain rods. Results clearly demonstrate the superiority of colloidal techniques, particularly for the Au-Rh case, in comparison to impregnation of the different metallic salts followed by reduction. While impregnation leads to the formation of a high proportion of Au or Rh monometallic particles, precise tuning of colloidal preparation conditions led to Au-Rh nanoalloys with controlled composition. Optimization of colloidal conditions was however found to be critical to avoid redissolution of Rh during preparation and formation of isolated Rh raft-like particles. Similar conditions were obtained for the Au-Pd bimetallic systems. Characterization by HRTEM, XPS, and EDX was performed after deposition on TiO2 nanorods. Finally, in the context of fuel upgrading, the catalysts have been evaluated in benzene hydrogenation in the presence of toluene and tetralin hydroconversion, both at high hydrogen pressure (4 MPa). In this contribution, the effect of gold addition on the hydrotreating and th ioresistance properties of rhodium will be presented and discussed on the basis of in-depth structural characterization. [1] D. Uzio, G. Berhault, Catal. Rev. 52 (2010) 106-131. [2] E.R. Essinger-Hileman, D. DeCicco, J.F. Bondi, R.E. Schaak, J. Mater. Chem. 21 (2011) 11599-11604 [3] Á. Kukovecz, G. Potari, A. Oszko, Z. Konya, A. Erdohelyi, J. Kiss, Surf. Sci. 605 (2011) 1048-1055

Supported Au-Rh nanoalloys for the hydrogenation of aromatics. [+ Affiche]

Internationa

Supported Au-Rh nanoalloys for the hydrogenation of aromatics

Internationa

Gold-based nanoalloy catalysts supported on titania nanorods

International @ RAFFINAGE+ZKO:GBE:PAF:LPIInternational audienceGold can be used as a modifier of platinum-group metals to increase the selectivity or stability of catalysts through alloying effects [1]. Au-M (M = Pd, Rh, Ru) nanoparticles have been synthesized by a colloidal route using PVA as surfactant and NaBH4 as reducing agent, following a modified version of the protocol reported by Hutchings group for Au-Pd [2]. The nanoparticles have been immobilized on rutile TiO2 nanorods synthesized by a hydrothermal method [3]. Au-Pd nanoparticles have also been grown under UHV by laser ablation and deposition onto TiO2 nanorods. The structural properties of the nanocatalysts have been investigated in details by several complementary techniques, including TEM, ETEM, EDX, XRD, XPS, and CO-FTIR, and their catalytic properties have been studied in catalytic hydrogenation [4] and oxidation reactions. In this communication, the three following aspects will be emphasized: 1) Optimization of the colloidal synthesis and post-treatment in order to produce well-defined and catalytically active supported nanoalloys; 2) Effect of the M metal identity on the atomic and chemical structure of Au-M, including under operando conditions; 3) Comparison between the chemical and physical routes in terms of structure and catalytic properties of Au-Pd/TiO2. [1]L. Piccolo in Nanoalloys: Synthesis, Structure and Properties, D. Alloyeau, C. Mottet, C. Ricolleau (Eds.), Springer, London, pp. 369-404 (2012) [2]G. J. Hutchings, C. J. Kiely, Accounts of Chemical Research 46 (2013), 1759. [3] H. Li, P. Afanasiev, Materials Research Bulletin 46 (2011), 2506. [4]Z. Konuspayeva, G. Berhault, P. Afanasiev, T.S. Nguyen, A. Auyezov, M. Burkitbayev, L. Piccolo, Proceedings of the MRS fall meeting (Boston, 2013)

Gold-based nanoalloy catalysts supported on titania nanorods

International @ RAFFINAGE+ZKO:GBE:PAF:LPIInternational audienceGold can be used as a modifier of platinum-group metals to increase the selectivity or stability of catalysts through alloying effects [1]. Au-M (M = Pd, Rh, Ru) nanoparticles have been synthesized by a colloidal route using PVA as surfactant and NaBH4 as reducing agent, following a modified version of the protocol reported by Hutchings group for Au-Pd [2]. The nanoparticles have been immobilized on rutile TiO2 nanorods synthesized by a hydrothermal method [3]. Au-Pd nanoparticles have also been grown under UHV by laser ablation and deposition onto TiO2 nanorods. The structural properties of the nanocatalysts have been investigated in details by several complementary techniques, including TEM, ETEM, EDX, XRD, XPS, and CO-FTIR, and their catalytic properties have been studied in catalytic hydrogenation [4] and oxidation reactions. In this communication, the three following aspects will be emphasized: 1) Optimization of the colloidal synthesis and post-treatment in order to produce well-defined and catalytically active supported nanoalloys; 2) Effect of the M metal identity on the atomic and chemical structure of Au-M, including under operando conditions; 3) Comparison between the chemical and physical routes in terms of structure and catalytic properties of Au-Pd/TiO2. [1]L. Piccolo in Nanoalloys: Synthesis, Structure and Properties, D. Alloyeau, C. Mottet, C. Ricolleau (Eds.), Springer, London, pp. 369-404 (2012) [2]G. J. Hutchings, C. J. Kiely, Accounts of Chemical Research 46 (2013), 1759. [3] H. Li, P. Afanasiev, Materials Research Bulletin 46 (2011), 2506. [4]Z. Konuspayeva, G. Berhault, P. Afanasiev, T.S. Nguyen, A. Auyezov, M. Burkitbayev, L. Piccolo, Proceedings of the MRS fall meeting (Boston, 2013)