Effects of Protease,Phytase and a Bacillus sp. Direct-Fed Microbial on Nutrient and Energy Digestibility,Ileal Brush Border Digestive Enzyme Activity and Cecal Short-Chain Fatty Acid Concentration in Broiler Chickens

Two experiments were conducted to determine the effects of protease and phytase (PP) and a Bacillus sp. direct-fed microbial (DFM) on dietary energy and nutrient utilization in broiler chickens. In the first experiment, Ross 308 broiler chicks were fed diets supplemented with PP and DFM in a 2×2 factorial arrangement. The 4 diets (control (CON), CON + PP, CON + DFM, and CON + PP + DFM) were fed from 15–21 days of age. In Experiment 1, significant interaction (P≤0.01) between PP and DFM on the apparent ileal digestibility coefficient for starch, crude protein, and amino acid indicated that both additives increased the digestibility. Both additives increased the nitrogen retention coefficient with a significant interaction (P≤0.01). Although no interaction was observed, significant main effects (P≤0.01) for nitrogen-corrected apparent ME (AMEn) for PP or DFM indicated an additive response. In a follow-up experiment, Ross 308 broiler chicks were fed the same experimental diets from 1–21 days of age. Activities of ileal brush border maltase, sucrase, and L-alanine aminopeptidase were increased (P≤0.01) by PP addition, while a trend (P = 0.07) for increased sucrase activity was observed in chickens fed DFM, in Experiment 2. The proportion of cecal butyrate was increased (P≤0.01) by DFM addition. Increased nutrient utilization and nitrogen retention appear to involve separate but complementary mechanisms for PP and DFM, however AMEn responses appear to have separate and additive mechanisms.     

Design of experiments in the biodegradation of phenol using immobilized Pseudomonas pictorum (NICM-2077) on activated carbon

Pseudomonas pictorum (NICM-2077) immobilized on various matrices are used to protect the microbes from confronting shock loads of concentrated phenol. The cells were immobilized in activated carbon and were used in biodegradation of phenol. Biodegradation of phenol using immobilized Activated Carbon matrix played an important role in reducing the toxicity of phenol. The degradation was carried and using the Box-Behnken model and analysis of variance have been applied to the experimental degradation studies. Response surface method with three levels of phenol concentration (0.200, 0.400, 0.600 g/l), activated carbon (0.5, 1.0, 1.5 g/l) and pH (7, 8, 9) were used in the identification of significant effects and interactions in the biodegradation studies. Phenol removal rate increases especially when the degradation medium was supplemented with utilizable carbon sources. A first-order polynomial regression model, which was used at first for analysis of the experiment had a significant lack of fit. Therefore, linear and quadratic terms were incorporated into the regression model through variable selection procedures. Effect of incubation phenol concentration, activated carbon and pH were significant. The predicted values using Box-Behnken model was found to be in close agreement with the experimental values, as indicated by the correlation coefficient values of 0.9463.     

Analysis of products formed during bleomycin-mediated DNA degradation

By the use of DNA, copolymers of defined nucleotide composition, and a synthetic dodecanucleotide having putative bleomycin cleavage sites in proximity to the 5'- and 3'-termini, the products formed concomitant with DNA strand scission have been isolated and subjected to structural identification and quantitation via direct comparison with authentic synthetic samples. The products of DNA strand scission by Fe(II)-bleomycin include oligonucleotides having each of the four possible nucleoside 3'-(phosphoro-2'-O-glycolates) at their 3'-termini, as well as the four possible base propenals. At least for 3-(adenin-9'-yl)propenal and 3-(thymin-1'-yl)propenal, the products formed were exclusively of the trans configuration.     

Production of prostacyclin by different cell types of the goat ovary

A sensitive platelet aggregation-inhibition assay was used to quantitate the production of prostacyclin by different cell types of the goat ovary. The assay could detect as low as 0.16 ng in the test sample. Different cell types i.e. granulosa, theca and corpus luteum or the total ovarian homogenate were incubated at 37° C for 10 minutes with or without 0.2mM arachidonic acid. Rat aortic strips were incubated under similar conditions as a positive control. Under basal conditions the amount of prostacyclin produced by corpus luteum cells was higher compared to that by granulosa cells. When the precursor of prostaglandins (arachidonic acid) was provided the production markedly increased in corpus luteum, granulosa, and ovarian homogenate as well as in aortic strips. Theca cells did not produce detectable levels of prostacyclin even when the precursor was provided. Trapidil did not alter the basal but enhanced the archidonic acid-stimulated prostacyclin production in homogenate and granulosa cells with no further increase in corpus luteum cells. U-51605 decreased basal as well as arachidonic acid-stimulated prostacyclin production in all the cell types. The prostacyclin production in ovaries is compartmentalized suggesting a possible role in ovarian physiology.     

Inhibitory effect of α-mangostin on Acinetobacter baumannii biofilms – an in vitro study

The present study was designed to investigate the anti-biofilm potential of alpha-mangostin (α-MG) against Acinetobacter baumannii (AB). The biofilm inhibitory concentration (BIC) of α-MG against AB was found to be 2 μg ml^?1. α-MG (0.5, 1 and 2 μg ml^?1) exhibited non-bactericidal concentration-dependent anti-biofilm activities against AB. However, α-MG failed to disintegrate the mature biofilms of AB even at a 10-fold increased concentration from its BIC. Results from qRT-PCR and in vitro bioassays further demonstrated that α-MG downregulated the expression of bfmR, pgaA, pgaC, csuA/B, ompA, bap, katE, and sodB genes, which correspondingly affects biofilm formation and its associated virulence traits. The present study suggests that α-MG exerts its anti-biofilm property by interrupting initial biofilm formation and the cell-to-cell signaling mechanism of AB. Additional studies are required to understand the mode of action responsible for the anti-biofilm property.     

Novel nicotinamide analog as inhibitor of nicotinamide N-methyltransferase

Nicotinamide N-methyltransferase (NNMT) has been linked to obesity and diabetes. We have identified a novel nicotinamide (NA) analog, compound 12 that inhibited NNMT enzymatic activity and reduced the formation of 1-methyl-nicotinamide (MNA), the primary metabolite of NA by ～80% at 2?h when dosed in mice orally at 50?mg/kg.     

Critical impeller speed for solid suspension in turbine agitated contactors

The present study in solid-liquid contactors, an attempt has been made to calculate the minimum/critical impeller speed required for complete suspension of solids. A new correlation, involving Reynolds number, modified Froude number, along with the agitation characteristics is proposed. The effect of impeller geometry as well as impeller clearance are clearly established for 6-blade (flat) turbine agitated contactors.List of Symbols B Solid weight fraction (%) - c Clearance of the impeller from the tank bottom (m) - d _P Average particle size(m) - d _R Impeller diameter (m) - d _T Vessel diameter (m) - g Acceleration due to gravity m/sec₂ - N _cs Critical impeller speed (S^–1) Greek Letters Kinematic viscosity m²/sec - _L Density of liquid kg/m³ - _S Density of solid kg/m³ - Density difference between solid and liquid kg/m³