Enhancement of the CO2 adsorption and hydrogenation to CH4 capacity of Ru-Na-Ca/γ-Al2O3 dual function material by controlling the Ru calcination atmosphere.

Integrated CO2 capture and utilization (ICCU) technology requires dual functional materials (DFMs) to carry out the process in a single reaction system. The influence of the calcination atmosphere on efficiency of 4% Ru-8% Na2CO3-8% CaO/γ-Al2O3 DFM is studied. The adsorbent precursors are first co-impregnated onto alumina and calcined in air. Then, Ru precursor is impregnated and four aliquotes are subjected to different calcination protocols: static air in muffle or under different mixtures (10% H2/N2, 50% H2/N2 and N2) streams. Samples are characterized by XRD, N2 adsorption-desorption, H2 chemisorption, TEM, XPS, H2-TPD, H2-TPR, CO2-TPD and TPSR. The catalytic behavior is evaluated, in cycles of CO2 adsorption and hydrogenation to CH4, and temporal evolution of reactants and products concentrations is analyzed. The calcination atmosphere influences the physicochemical properties and, ultimately, activity of DFMs. Characterization data and catalytic performance discover the acccomodation of Ru nanoparticles disposition and basic sites is mostly influencing the catalytic activity. DFM calcined under N2 flow (RuNaCa-N2) shows the highest CH4 production (449 µmol/g at 370°C), because a well-controlled decomposition of precursors which favors the better accomodation of adsorbent and Ru phases, maximizing the specific surface area, the Ru-basic sites interface and the participation of different basic sites in the CO2 methanation reaction. Thus, the calcination in a N2 flow is revealed as the optimal calcination protocol to achieve highly efficient DFM for integrated CO2 adsorption and hydrogenation applications.

Effects of a direct fed microbial (DFM) on broiler chickens exposed to acute and chronic cyclic heat stress in two consecutive experiments.

Two consecutive 35 d experiments were conducted to investigate the effects of a multistrain DFM fed continuously to broiler chickens exposed to HS from 28 to 35 d on broiler performance, body composition, ileal digestibility, and intestinal permeability using serum Fluorescein Isothiocyanate Dextran (FITC-d) concentration. The treatments were arranged as a 2 × 2 factorial with temperature: Elevated (HS: 33 ± 2°C for 6 h and 27.7°C for the remaining 18 h from 28 to 35 days of age) and Thermoneutral (TN: 22 to 24°C over the entire 24-h day from 28 to 35 days of age) and diet: corn-soybean meal based with and without DFM (3-strain Bacillus; Enviva PRO) fed over the entire 35-d period as the two factors. Experimental diets were formulated to meet all nutrient recommendations based on breed standards using a starter (0-10 d), grower (10-21 d), and finisher (21-35 d) period. For each of the 2 experiments, 648 Ross 708 broiler chicks were allotted among the treatments with 9 replicate pens of 18 broilers. Data were analyzed as a 2 × 2 factorial within each experiment in JMP 14. In both experiments, cloacal temperatures were increased (P ≤ 0.05) in the broilers subjected to the HS treatment at both 28 d (acute) and 35 d (chronic). Supplementing birds with DFM reduced cloacal temperatures in the Experiment 1 at 28 d, but not at the other time periods. The HS treatment reduced body weight gain and lean tissue accretion from 0 to 35 d in both experiments (P ≤ 0.05). In Experiment 2, when the litter was reused BWG was increased by 36 g/bird with supplementation of DFM (P ≤ 0.05). Ileal digestibility at 28 d (2 h post HS) was improved with DFM supplementation in both experiments (P ≤ 0.05). Serum FITC-d increased with HS at both 28 and 35 d. Serum FITC-d was generally decreased with DFM at 28 d but the response was inconsistent at 35 d. Overall, the results suggest that HS reduced broiler performance and DFM treatment improved intestinal permeability and nutrient digestibility responses to HS in both experiments but did not improve performance until built up litter was used in Experiment 2.

Effects of feed supplementation with 3 different probiotic Bacillus strains and their combination on the performance of broiler chickens challenged with Clostridium perfringens.

The application of probiotics in broiler feed, to alleviate performance deficiencies due to mild infections by coccidia and Clostridium perfringens, is of increasing interest for the poultry industry. Therefore, our objective was to evaluate the capacity of 3 Bacillus strains and their combination as probiotics in vitro and in vivo. Thus, protein and carbohydrate degradation and C. perfringens growth inhibition capabilities were assessed by colometry measurement and an agar diffusion bioassay, respectively. A total of 2,250 1-day-old male broiler chicks were assigned to 5 dietary treatments: 1) non-probiotic-supplemented control (control); 2) control + DSM 32324 at 0.8 × 106 cfu/g of feed; 3) control + DSM 32325 at 0.5 × 106 cfu/g of feed; 4) control + DSM 25840 at 0.3 × 106 cfu/g of feed; and 5) control + DSM 32324 + DSM 32325 + DSM 25840 at 1.6 × 106 cfu/g of feed. A pathogenic field strain of C. perfringens was used to induce the necrotic enteritis challenge on day 19, 20, and 21. All birds and remaining feed were weighed on pen basis on day 0, 21, 35, and 42, to calculate BW gain and mortality-adjusted feed conversion. Mortality and mortality due to necrotic enteritis were recorded daily. On day 21, 45 birds per treatment were evaluated for macroscopic intestinal necrotic enteritis lesions. Performance data were statistically analyzed using an ANOVA and subjected to a least significant difference comparison. Necrotic enteritis lesion scores were statistically analyzed using nonparametric Kruskal-Wallis test. Dunn's test was used for treatment comparison. The tested strains showed different abilities of degrading protein and carbohydrates and inhibiting C. perfringens growth in vitro. The birds fed the multi-train combination presented significantly better performance and lower necrotic enteritis lesion score than those in the control group. Dietary supplementation with probiotics resulted in significantly lower necrotic enteritis mortality. The results demonstrate the suitability of the evaluated Bacillus multistrain combination as an effective probiotic in C. perfringens-challenged chickens.

Effect of Bacillus-direct-fed microbial on leaky gut, serum peptide YY concentration, bone mineralization, and ammonia excretion in neonatal female turkey poults fed with a rye-based diet.

Rye is high in nonstarch polysaccharides (NSP), a complex carbohydrate which cannot be digested by poultry as they lack the endogenous enzymes to do so. Exogenous carbohydrases must therefore be supplemented to avoid the antinutritional effects associated with a high NSP diet. The objectives of the present study were to evaluate the effects of a rye-based diet with and without supplementation of a Bacillus direct-fed microbial (DFM) on body weight, bone mineralization, and leaky gut, as well as its role on influencing serum concentrations of peptide YY (PPY) and the ammonia concentration in turkey manure. Two independent trials were conducted. In each experiment, day-of-hatch female turkey poults were neck tagged and randomly assigned to either a control rye-based diet or a rye-based diet supplemented with the DFM (n = 25 birds/group). At 10 days-of-age, poults in both groups were administered with an appropriate dose of fluorescein isothiocyanate-dextran (FITC-d) by oral gavage. One hour later, all poults were euthanized. Blood was collected to evaluate serum FITC-d and PPY concentrations. Furthermore, in Trial 2 only, both tibias were removed for assessment of bone parameters, and turkey manure was collected to evaluate physicochemical analysis. In both trials, poults treated with the DFM showed a significant increase (P < 0.05) in body weight and body weight gain as compared with control nontreated poults. Poults that received the DFM also had a significant reduction in serum levels of PPY and FITC-d when compared with control nontreated poults. In Trial 2, turkeys treated with the DFM had a substantial increase in tibia strength, tibia diameter, total ash, calcium, and phosphorus when compared with control nontreated turkeys. Their manure was also shown to have a significant reduction in the concentration of ammonia. This is the first report of a commercial DFM reducing the concentration of this compound in turkey manure. In summary, the results of the present study confirm that turkeys fed with a rye-based diet have a significant increase in gut permeability, a reduced body weight, and decreased bone mineralization when compared with turkeys fed with the DFM. Turkeys that received the rye-based diet supplemented with the Bacillus-DFM also had a significant reduction in the serum concentration of PPY when compared with control turkeys. This finding suggests a possible prebiotic effect of rye, warranting future studies to test this effect. Further studies to evaluate the microbiota diversity, as well as the concentration of ceca short-chain fatty acids, are also necessary to confirm the reliability of PPY as a potential metabolomic biomarker in poultry.

The effectiveness of a dietary direct-fed microbial and mannan oligosaccharide on ultrastructural changes of intestinal mucosa of turkey poults infected with Salmonella and Campylobacter.

Salmonella and Campylobacter are considered major public health burdens worldwide, and poultry are known to be one of the main reservoirs for these zoonotic pathogens. This study was conducted to evaluate the effect of a commercial probiotic or direct-fed microbial (DFM) Calsporin (CSP), and prebiotic or mannan oligosaccharide (MOS) (IMW50) on ultrastructural changes and the villous integrity of intestinal mucosa in turkey poults challenged with Salmonella and Campylobacter. A 21-day battery cage study was conducted using 4 dietary treatments including a basal diet (corn and soybean-based) nonsupplemented and uninfected as a negative control (NC); basal diet supplemented with 0.05% DFM (CSP); basal diet supplemented with 0.05% MOS (IMW50); and basal diet supplemented with 0.05% mixture of DFM and MOS at equal proportions. Female large white turkey poults aged 336 days were obtained from a local commercial hatchery and randomly distributed in electrically heated battery cages with 12 treatments of 4 replicates per treatment containing 7 poults per pen. The first 16 pens were not infected with bacteria, poults in pens 17-32 were orally challenged at day 7 with 105 cfu Salmonella Heidelberg, and the poults in pens 33-48 were orally challenged at day 7 with 105 cfu Campylobacter jejuni. Feed and water were provided ad libitum throughout the study. At day 21, ileal tissue samples from 1 bird per cage were collected for intestinal integrity and ultrastructural examination by scanning and electron microscopy. DFM and MOS supplementation was effective in both challenged and nonchallenged (not infected with Salmonella and Campylobacter) birds. Goblet cells and mucus were increased, with the presence of large numbers of segmented filamentous bacteria in DFM- and MOS-supplemented groups compared with birds in control treatments. The number and size of villi were reduced in poults exposed to Salmonella and Campylobacter. Results show that CSP and IMW50 provide protection of ileal mucosal integrity in poults exposed to Salmonella or Campylobacter.

Effects of microbial feed additives on feed utilization and growth performance in growing Barki lambs fed diet based on peanut hay.

The effects of supplementing diet of growing lambs with microbial feed additive mixture (direct-fed microbial; DFM) based on Saccharomyces cerevisiae, lactic acid bacteria and exogenous enzymes on feed intake, nutrient digestibility, nitrogen (N) utilization, ruminal fermentation, blood chemistry and growth performance were studied. The study was a completely randomized design with 12 growing Barki lambs divided into two groups of six lambs per treatment. Lambs were offered a control diet of peanut hay and concentrates (1:1 dry matter (DM) basis) or the control diet supplemented with DFM at 0.5 g/day (Bactozyme treatment) for 16 weeks. There was no effect on feed efficiency but Bactozyme lambs had increased (p = 0.009) feed intake, average daily gain (p = 0.042) and final body weight (p = 0.047). Bactozyme treatment had greater neutral detergent fiber (p = 0.020) and acid detergent fiber (p = 0.034) digestibility compared with the control treatment. Metabolism experiment showed that the feed additive mixture increased (p<0.05) N intake and N retention. Bactozyme treatment had greater blood total protein (p = 0.027), and globulin (p = 0.025) concentrations compared with the control treatment. It is concluded that supplementing growing Barki lambs with DFM at 0.5 g daily enhanced final body weight gain and fiber digestion without affecting feed efficiency.

Core-shell assay based aptasensor for sensitive and selective thrombin detection using dark-field microscopy.

In this work, we developed a robust and ultrasensitive bio-sensor based on the target-aptamer recognition strategy and microscopic enumeration of gold nanoparticles (AuNPs) using dark field microscopy (DFM). The aptasensor with a core-shell structure consisting of a magnetic bead (MB), aptamer and AuNPs was fabricated by complementary hybridization of the DNA probe on the AuNPs surface to the aptamer coupled to the MB. Upon addition of the target molecule, the strong interaction between the aptamer and the target molecule, thrombin, results in the release of the AuNPs from the MB. The quantities of thrombin is therefore linearly correlated to the number of the released AuNPs, which can be digitally counted using DFM. To demonstrate the feasible use of the aptasensor for target detection, thrombin was evaluated as the model target. The limit of detection was determined to be 2.54 fM with dynamic range of 6 fM-100 fM. When the concentration of thrombin exceeded 100 fM, the counted number of AuNPs didn't correlate linearly to molecules of thrombin anymore, as the nanoparticles aggregated partly due to high concentration. However, the color of the solution changes to purple and the concentration of free AuNPs can be conveniently quantified by UV-Vis spectroscopy for up to 100 nM. It is noteworthy that our aptasensor is very easy to operate and requires neither complex isolation and amplification processes nor expensive instruments and consumables. Furthermore, this strategy can be easily generalized to other targets by replacing the corresponding aptamers and show great potential for the detection of biomarkers in clinical samples.

Effects of direct-fed microorganisms and enzyme blend co-administration on intestinal bacteria in broilers fed diets with or without antibiotics.

Direct-fed microorganisms (DFM) and exogenous enzymes have been demonstrated to improve growth performance in poultry and are potentially important alternatives to antibiotic growth promoters (AGP). We investigated the administration of a feed additive composed of a DFM product containing spores of 3 Bacillus amyloliquefaciens strains and an enzyme blend of endo-xylanase, α-amylase, and serine-protease in diets with or without sub-therapeutic antibiotics in broiler chickens over a 42-d growth period. Evaluation of growth performance determined feed efficiency of broiler chickens which were administered the feed additive was comparable to those fed a diet containing AGPs. Characterization of the gastrointestinal microbiota using culture-dependent methods determined administration of the feed additive increased counts of total Lactic Acid Bacteria (LAB) relative to a negative control and reduced Clostridium perfringens to levels similar to antibiotic administration. Additionally, greater counts of total LAB were observed to be significantly associated with reduced feed conversion ratio, whereas greater counts of C. perfringens were observed to be significantly associated with increased feed conversion ratio. Our results suggest the co-administration of DFMs and exogenous enzymes may be an important component of antibiotic free poultry production programs and LAB and C. perfringens may be important targets in the development of alternatives to AGPs in poultry production.

Effects of the inclusion of a Bacillus direct-fed microbial on performance parameters, bone quality, recovered gut microflora, and intestinal morphology in broilers consuming a grower diet containing corn distillers dried grains with solubles.

Distillers dried grains with solubles (DDGS) have increasingly been used in poultry diets as a consequence of rising grain costs. Some, but not all, sources of DDGS have a variable compositional value, and a high inclusion of this by-product could be considered a risk factor for presentation of enteric diseases. Presently, 2 experiments were conducted using a starter corn-soybean diet (zero to 7 d) and a corn-DDGS-soybean grower diet (8 to 28 d) with or without inclusion of a Bacillus-direct-fed microbial (DFM). In both experiments, day-of-hatch chicks were randomly assigned to 2 different groups: control group without DFM or Bacillus-DFM group, containing 106 spores/g of feed. In each experiment, 8 pens of 20 chicks (n = 160/group) were used. Performance parameters of BW, BW gain (BWG), feed intake (FI), and feed conversion (FCR) were evaluated in each growth phase. Additionally, in experiment 2, intestinal samples were collected to determine duodenal and ileal morphology (n = 8/group), as well as the microbiota population of total lactic acid bacteria (TLAB), total Gram-negative bacteria (TGNB), and total anaerobic bacteria (TAB) on d 28 (n = 16/group). Furthermore, both tibias were evaluated for bone strength and bone composition (n = 16/group). In both experiments BW, BWG, and FCR were improved by the DFM when compared to the control group (P < 0.05). In experiment 2, chickens supplemented with the DFM had less TGNB in the foregut intestinal segment and higher TLAB counts in both foregut and hindgut sections (P < 0.05). In addition significant increases in tibia breaking strength and bone mineralization were observed in the DFM group when compared with the control. In the case of intestinal morphology, DFM dietary inclusion increased villus height (VH), villus width, villus area, muscular thickness, and the VH to crypt depth ratio (VH:CD) in both duodenum and ileum sections. Results of the present study suggest that consumption of a selected Bacillus-DFM producing a variable set of enzymes could contribute to enhanced performance, intestinal microbial balance, and bone quality in broiler chickens consuming a grower diet that contains corn-DDGS.