جستجوی مقالات مرتبط با کلیدواژه "آنزیم‎" در نشریات گروه "دامپزشکی"

15acetyl-deoxynivalenol (15ADON) is the most common chemotype of dioxynivalenol (DON) mycotoxin, which cannot be controlled by common methods such as absorbents. Hence, enzyme-based methods are suggested for detoxification of these types of mycotoxins, which requires bioinformatics studies before laboratory investigations. Therefore, the aim of the present study was to investigate the binding energy of DEP-A and DEP-B enzymes with 15ADON through molecular docking. The three-dimensional structures of DEP-A and DEP-B proteins were predicted using the SWISS MODEL server. Then, the stability of these structures was evaluated in molecular dynamic conditions. For this purpose, the simulation was carried out with GROMACS software and then the RMSD curve of these two enzymes was drawn to check the stability of the predicted structure. H-DOCK online server was used to performed the interaction of DEP-A enzyme with 15ADON and DEP-B with Oxid15ADON intermediate. Checking the accuracy of the predicted structures by ERRAT Verify3D, Z-score and Ramachandran plots showed that the prediction of tertiary structures successfully performed. The RMSD curves showed that DEP-A and DEP-B were stabilized in 240 and 40 nanoseconds with 0.58 and 0.35 nm, respectively. The results of molecular docking also showed that both DEP-A and DEP-B enzymes could bind to their substrates with relatively strong binding energy -157.90 and -141.78, respectively. Overall, it can be concluded that both studied enzymes were able to bind to the 15ADON chemotype of DON in the appropriate position, which shows that these enzymes can be effective in deactivating this chemotype, although laboratory studies are needed to confirm the results

Oxidative stress is believed to be one of the major causes of tissue damage in aquatic animals exposed to heavy metals. It leads to certain changes in the antioxidant and enzyme system. Given the fact that research on the effect of sub-acute toxicity of silver nitrate in shrimps is not very developed, the present study can be conducive to formulating the international standards of contamination of shrimps with silver nitrate.

The present study aimed to evaluate the toxic effects of silver nitrate on the changes in the antioxidant and enzyme systems of hepatopancreas, muscle and gills of Litopenaeus vannamei.

After acclimatization of shrimps, they were exposed to silver nitrate with concentrations of 0.0084, 0.021, 0.042 and 0.063 mg/L for 21 days. At the end of the experimental period, gill, muscle and hepatopancreas were sampled, and the changes in the antioxidant system (SOD, GPx and GST) and metabolic enzymes (ALT, ALP, AST and LDH) were examined.

There was no significant difference in terms of SOD and GST activity in the gill and muscle of the exposed shrimps (P>0.05). However, GPx in treatment 4 increased significantly in gill and muscle while it saw a decrease in hepatopancreas (P<0.05). In hepatopancreas, GST significantly increased in treatments 3 and 4 (P<0.05) whereas SOD did not show any significant changes compared with other treatments (P>0.05). The metabolic enzymes of the muscle did not show any significant differences in any of the treatments (P>0.05), but in gill, the level of ALT in treatment 4 decreased significantly while the levels of AST and LDH in treatment 3 and 4 significantly increased (P<0.05). In hepatopancreas, the activity of ALT in treatments 2 and 4, AST in treatments 3 and 4, and ALP in all treatment except treatment 1 saw significant reduction. Nevertheless, LDH in treatments 3 and 4 had a significant rise (P<0.05).

A significant increase in GST and LDH as well as a significant decrease in GPx and ALT, AST and ALP enzymes in the hepatopancreas revealed that the antioxidant and enzyme system of shrimps is further disturbed with the rise in silver nitrate concentration in the hepatopancreas compared to the gill and muscle.

Today, fungal toxins or mycotoxins are a major problem in the food industry and food chain safety, which can contaminate a wide range of agricultural products, and thus they have negatively affect on health and production of livestock and poultry, and consequently human health, the economies of countries and even international trade. Since mycotoxin contamination cannot be completely prevented before or after harvest, it is important to know exactly how to remove mycotoxins during technological processes and feed clearance strategies. Today, the biological control of mycotoxins by microorganisms and other biological factors is becoming a valid approach to protect food products from contamination by these toxins, which increases the safety and quality of crops and animal feed, and ultimately reduces toxin concentration in animal products (milk, meat and eggs), and increase food chain security.

This experiment was conducted to evaluate the effect of electron beam-irradiated barley on viscosity, microbial population, digestive enzyme activities, histomorphometrical structure of broiler chicks. Treatments were barley at levels of 25% and 50% (raw and irradiated at 40 kGy) and corn-soya bean meal diet (as control, without barley) that used with five dietary treatments, four replicates and 12 birds of each for 42 days in a completely randomized design. Increasing levels of barley to 50% (raw or irradiated) in the diet significantly increased ileal viscosity compared to the other treatments. Broilers fed 50% irradiated barley diet had significantly lower viscosity compared to the broilers fed 50% raw barley. The inclusion of barley in the diet resulted in significantly decreased ileal pH when compared with a control diet. However, radiation of barley had no significant effect on ileal pH of broilers. Caecal populations of Coliform, E. coli and total aerobic bacteria were not influenced by the experimental treatments. Also the caecal population of Lactobacillus was decreased in broilers fed on 50% raw barley compared to 25% irradiated barley and control diet. No significant differences were observed among dietary treatments on amylase and protease activities of the jejunal digesta and in pancreatic tissue. Broilers fed 50% barley (raw or irradiated) diet had significantly higher lipase activities in pancreatic tissue compared to the other treatments. The villus height, villus width, crypt depth, crypt width, the ratio of villus height to crypt depth, epithelial thickness, muscle thickness, number of goblet cells and a total wall thickness of the duodenum and jejunum were not affected by the experimental treatments. The results of this study showed that radiation significantly decreased viscosity at the level of 50% barley. However, radiation was no significant effect on pH, microbial population, enzyme activities, histomorphometry of duodenum and jejunum.

The aim of this experiment was to investigate the effect of processing date palm leaves with urea and enzyme on digestibility, rumination and some blood and rumen parameters of Arabian sheep. In this research, 16 Arabian sheep with an average age of 8 months and weight 28 ± 1.5 kg were used. The ratio of concentrate/forage in the treatments was 50:50. Treatments were including 1) diet contains wheat straw (control), 2) diet contains crude date palm leaves, 3) diet contains crude date palm leaves+ 3 g/kg Natuzyme enzyme and 4) diet contains date palm leaves processed with 4 % urea. In this experiment it is considered 21 days for adaptation and 14 days for sampling. At the end of the experiment, nutrient digestibility, feeding behavior and blood and rumen parameters were determined and the obtained data were analyzed in completely randomized design. Results showed feed intake, digestibility of dry matter and organic matter and blood cholesterol level were not influenced by experimental diets (P>0.05). However, digestibility of NDF and ADF, blood glucose and urea and ruminal ammonia concentration significantly increased in sheep fed with date palm leaves processed with urea (P