The potential of dietary lipases to improve fat utilization in young birds

In comparison to the adult birds, young chickens and turkeys have a reduced ability to use dietary fat. It was of interest to investigate the role of lipase in fat malabsorption in young birds. It was hypothesized that fat malabsorption in young chickens and turkeys is due to an insufficiency of pancreatic lipase. It was further hypothesized that fat utilization in young birds can be improved by the use of dietary lipase sources. The first in vitro experiment characterized the activity and stability of mammalian, fungal and bacterial lipase sources when exposed to conditions associated with the proventriculus of young birds. The results of this study demonstrated that bacterial Pseudomonas sp. and Chromobacterium viscosum lipase sources are more stable under conditions that mimic the glandular stomach of young birds. Aspergillus niger lipase also showed a relatively high activity in acidic conditions. Mammalian crude porcine lipase was irreversibly inhibited in these conditions. The second in vitro study tested crude porcine, bacterial Pseudomonas sp. and Chromobacterium viscosum, and fungal Aspergillus niger lipase sources under conditions which approximate the small intestine. It was concluded that Pseudomonas sp. lipase had potential as a supplement in poultry diets. Two in vivo experiments were completed to test the use of Pseudomonas sp. lipase in diets of young broiler chickens and turkeys. The first experiment studied the impact of five levels of enzyme addition (0, 50, 100, 200 and 400 units per gram of diet) in a corn-soybean meal based diet containing 8% tallow and fed to broiler chickens from 0 to 35 days of age. The results indicated that lipase addition has a negative impact on body weight gain, feed efficiency and fat digestibility. Analysis of feeds containing 0 and 400 units per gram of diet revealed that triglycerides had been nearly totally hydrolyzed to free fatty acids and glycerol during feed mixing and/or storage in the enzyme supplemented treatment. The second experiment utilized the same enzyme source at four lower levels (0, 20, 40 and 60 units per gram of diet) in diets for turkey poults under study from 0 to 21 days of age. The production results of this trial were similar but less severe than those seen for chickens. The results of this research do not permit the acceptance or rejection of thesis hypotheses. The unexpected finding that the lipase used in in vivo experiments can hydrolyze triglycerides prior to consumption by birds is undesirable and raises a number of questions. (Abstract shortened by UMI.

Inhibition Effect of Lactic Acid Bacteria against Food Born Pathogen, Listeria monocytogenes

In recent years due to changes in lifestyle and eating behavior of the human populations, disease caused by contaminated food has increased significantly. Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enteric are three of the most important food borne bacterial pathogens and can lead to food borne diseases. Also today wide spread of resistance to antibiotics among bacteria occurs due to increased consumption of antibiotics. Therefore, there is a dire need for development of new types of safe antimicrobial compounds. In this field, the most extensive research and commercial practices are based on probiotic bacteria. Probiotics, specifically lactic acid bacteria, are broadly used in the food industry for fermentation. Furthermore, probiotics produce valuable antimicrobial products that results to health effects. Now, the use of probiotic for treatment of disease is thought to be an effective way to improve the gut health and an alternative for treatment by antibiotics. Probiotics contribute to food safety by inhibition of the growth of other bacteria. Lactic acid bacteria can be used as protective cultures to compete with several pathogens and undesired organisms. Since food safety has become a significant international concern, here we investigated application of lactic acid bacteria for controlling the growth of Listeria monocytogenes

Optimization of dendrimer polyamidoamin eectrospun nanofibers: preparation and properties

Background: The most common polymers in the treatment of wounds are natural (e.g., polysaccharides, proteins, and peptides) and synthetic polymers (e.g., poly-glycolic acid, polyacrylic acid, polylactic acid, and polyvinyl alcohol) due to their biodegradability, biocompatibility, and their structural resemblance to the macromolecules known to the human body. Objectives: The current study aimed to develop an electrospinning method using the nanofibers of polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC)/polyamide amine (PAMAM)/tetracycline (Tet) to cover the wound. The antibacterial effect of PAMAM was also tested against E. coli and S. aureus bacteria. Materials and Methods: The morphology of the composite nanofiber was studied by a field emission scanning electron microscope. Infrared spectroscopy (FTIR) was used to characterize the nano chemical structure. Results: Nanofibers were evaluated based on the release of different amounts of the antibiotic tetracycline (1%, 3%, 5%, and 7% by weight) while preventing wound infection. The findings indicated that the highest-profile release of all nanofibers occurred early within 12 hours. It was found that nanofiber membranes loaded with 1%, 3%, and 5% tetracycline released drugs for over 28 days, while those containing 7% tetracycline released drugs for more than 14 days. Conclusions: According to the findings related to the drug release of PVA/CMC/15% PAMAM/Tet and surface morphology of the nanofibers, the optimal amount of Tet was 5%. The results of FTIR spectroscopy indicated that the tetracycline and polyamidoamine were successfully placed in nanofibers

Evaluation of corn meal on performance, carcass characteristics and nutrient digestibility of male broiler chickens

To study the effect of corn meal (CM) on performance, carcass characteristics and nutrient digestibility of chickens in a completely randomized design experiment with 4 × 2 factorial arrangement and 4 replicates per treatment, 384 Ross male broiler chickens in a 49 days period were evaluated. Treatments were 0 (CM0), 15 (CM15), 30 (CM30), or 45 (CM45) CM to replace corn and 2 levels of commercial NSP-degrading enzyme (0 and 0.025%). Corn meal had no effect (P > 0.05) on body weight gain, feed intake and carcass characteristics during the whole brooding period. Dietary corn meal level (CM45) had significant effect on digestibility of fat, apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen (AMEn). However, enzyme supplementation significantly increased phosphorous digestibility (P < 0.05). Interaction between corn meal level and enzyme supplementation had significant effect on excreta dry matter (DM), organic matter (OM), crude protein (CP), AME and AMEn during 0 to 49 days of age. Together, the results suggested that replacement of corn by corn meal may affect the digestibility of OM, CP, AME, AMEn, and enzyme supplementation has some beneficial effects on theses traits.Keywords: Corn meal, enzyme, broiler chickens, performance, carcass characteristics, nutrient digestibilit

Effects of dietary crude protein and calcium/ phosphorus content on growth, nitrogen and mineral retention in broiler chickens

This experiment was conducted to examine the effect of three levels of crude protein (CP) (NRC, 15% more than NRC and 15% less than NRC) and three levels of Ca and available P (Av. P) (NRC, 15% more than NRC and 15% less than NRC) on performance of broilers from hatching until 21 days of age. The experimental design was a completely randomized design (CRD), with a 3 × 3 factorial arrangement of nine dietary treatments. Each treatment combination had four replicate pens (10 birds per pen). Results of this experiment showed that CP content had no significant effect on feed and water intake. However, body weight gain (BWG) significantly reduced and FCR increased (P < 0.05) by 15% change in CP content of diet. Fifteen percent increase in mineral content of diets had no significant effect on feed intake. However, increase in Ca and Av. P significantly increased BWG and resulted in an improved feed conversion ratio (FCR) and increased water intake. There was an interactive effect of CP by Ca and Av. P levels on feed intake, BWG and FCR. A change in CP or mineral content of the diets had no significant effect on blood parameters except for potassium concentration (K+). Reducing CP, Ca and Av. P content of the diet significantly (P < 0.001) increased P, Ca and N retention. Reduction in CP content of the diet led to a decrease in length, P and tibia bone ash. There was an interactive effect of CP by Ca and Av. P on the retention of Ca, N and ash of tibia bone.Key words: Crude protein, Ca and Av. P levels, broilers, N retention

The effect of nisin on biofilm-forming and pathogenic bacteria using micro titer plate method

چکیده: زمینه و هدف: بعضی از باکتریهای پاتوژن و فاسد کننده مواد غذایی قادر می‌باشند به سطوح در تماس با مواد غذایی متصل شده و تشکیل بیوفیلم ‌دهند، از این جهت به ‌عنوان منبع آلودگی محصولات غذایی و انتقال بیماری ها در نظر گرفته می‌شوند. نیزین، باکتریوسین پپتیدی می‌باشد که برای کنترل بیولوژیکی بیوفیلم های میکروبی استفاده می‌گردد. همچنین امروزه نیزین در ادغام با مواد بسته‌بندی، مواد غذایی را از خطر فساد و ورود عوامل بیماریزا محافظت می‌کند. هدف از این مطالعه بررسی اثر غلظت های مختلف نیزین بر روی برخی از باکتریهای بیماریزای غذایی بوده است. روش بررسی: در این تحقیق تجربی اثرات غلظت های مختلف نیزین بر باکتریهای تشکیل‌دهنده بیوفیلم و بیماریزای Staphylococcus aureus، Listeria monocytogenes و Salmonella enteritidis با روش میکروتیترپلیت بررسی شد. میزان کاهش سلول های تشکیل‌دهنده بیوفیلم با استفاده از دستگاه الیزا ریدر و میزان کشته‌ شدن سلول ها با به‌کاربردن رنگ TTC (Triphenyl Tetrazolium Chloride) تعیین شد. داده ها با استفاده از آزمون های آنالیز واریانس و آزمون مقایسه ای Kramer-Tukey و به کمک نرم افزار Minitab تجزیه و تحلیل شد. یافته‌ها: نتایج نشان داد نیزین در غلظتی که مصرف آن مجاز است (IU/ml103´4)، بر بیوفیلم S. enteritidis نسبت به بیوفیلم باکتری های L. monocytogenes و Staph. aureus به ترتیب با 87، 57 و 30 درصد موثرتر می‌باشد (05/0

Production, characterization and application of nano - phase change materials: a review

Phase Change Materials (PCMs) for heat storage and energy saving has been extensively used in many fields for heating and cooling processes, including building, solar energy, textiles, agriculture, and electronics. PCMs have been getting incredible attention for being low-cost materials and have potential materials for thermal energy storage (TES) with long cycle life. Though, the disadvantages such as flow, result in encapsulation in three scales of Macro, Micro and Nano capsules. Encapsulating PCM reduces the disadvantages and improves the efficiency of PCMs. Different methods for producing PCMs in the scale of nano and core-shell materials, have been developed and the capsules size in relation to parameters such as pH, stirring rate, material selection and preparation method have been investigated. In recent years, this subject has been extensively studied, seeking to find more efficient and safer PCMs. In this context, nanoscale PCMs have been produced and applied to the most diverse products and their performance evaluated. They simply modified and optimized production processes. The novelty of this study lies in the fact that merely a few articles have reviewed nano-encapsulating of PCMs, focusing on new developments on PCM nanocapsules. Moreover, few articles have compared nano and microcapsules of PCMs so far. The analysed papers suggest that the production methods influence the size of the obtained capsules. The purpose of this article is to make an updated review of the synthesis and application of nano-encapsulated PCMs

Biodegradation of microcystin-LR using acclimatized bacteria isolated from different units of the drinking water treatment plant

Bacterial community isolated from different units of a Drinking Water Treatment Plant (DWTP) including pre-ozonation unit (POU), the effluent-sludge mixture of the sedimentation unit (ESSU) and top-sand layer water sample from the filtration unit (TSFU) were acclimatized separately in the microcystin-leucine arginine (MC-LR)-rich environment to evaluate MC-LR biodegradation. Maximum biodegradation efficiency of 97.2 ± 8.7% was achieved by the acclimatized-TSFU bacterial community followed by 72.1 ± 6.4% and 86.2 ± 7.3% by acclimatized-POU and acclimatized-ESSU bacterial community, respectively. Likewise, the non-acclimatized bacterial community showed similar biodegradation efficiency of 71.1 ± 7.37%, 86.7 ± 3.19% and 94.35 ± 10.63% for TSFU, ESSU and POU, respectively, when compared to the acclimatized ones. However, the biodegradation rate increased 1.5-folds for acclimatized versus non-acclimatized conditions. The mass spectrometry studies on MC-LR degradation depicted hydrolytic linearization of cyclic MC-LR along with the formation of small peptide fragments including Adda molecule that is linked to the reduced toxicity (qualitative toxicity analysis). This was further confirmed quantitatively by using Rhizobium meliloti as a bioindicator. The acclimatized-TSFU bacterial community comprised of novel MC-LR degrading strains, Chryseobacterium sp. and Pseudomonas fragi as confirmed by 16S rRNA sequencing. Biodegradation of microcystin-LR by in-situ bacterial community present in the drinking water treatment plant without formation of toxic by-product.Fil: Kumar, Pratik. Université du Québec a Montreal; CanadáFil: Hegde, Krishnamoorthy. Université du Québec a Montreal; CanadáFil: Brar, Satinder Kaur. Université du Québec a Montreal; CanadáFil: Cledón, Maximiliano. Universidad Nacional del Comahue; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kermanshahi-pour, Azadeh. Dalhousie University Halifax; CanadáFil: Roy-Lachapelle, Audrey. University of Montreal; CanadáFil: Galvez-Cloutier, Rosa. Laval University; Canad