Improvement of growth performance,digestive enzymes and body composition of Persian sturgeon (Acipenser persicus) following feeding on probiotics: Bacillus licheniformis,Bacillus subtilis and Saccharomyces cerevisiae

The individual and combinational effects of probiotics on Persian sturgeon (Acipenser persicus) were evaluated through assessing the growth performance, proximate body composition, digestive enzymes and intestinal morphology. On the basis of feeding with experimental diets, the fish were assigned into four groups denoted as follows: control (basal diet), D‐Pro (basal diet + Bacillus subtilis and Bacillus licheniformis), D‐Pro/Yeast (basal diet + B. subtilis and B. licheniformis + Saccharomyces cerevisiae), Yeast (basal diet + S. cerevisiae). Maximum mean weight and length were measured for the fish fed with D‐pro regime. weight gain (WG), body weight gain (BWI%),  feed efficiency (FE%), protein efficiency rate (PER), lipid efficiency rate (LER), and condition factor (CF) demonstrated the highest values for the fish fed with the diets containing D‐Pro and/or D‐Pro/yeast. LER and food conversion ratio (FCR) showed the highest performance for the fish received the D‐Pro diet. The diets containing D‐Pro exhibited higher performance in enhancing the activity of protease and lipase than the one supplemented only with the yeast, whereas the regimes treated with the yeast exhibited higher amylase activity. The fish received D‐Pro exhibited the highest protein and fat contents, yet did the lowest contents of moisture and total ash. Taken together, the findings revealed that the dietary administration of the D‐Pro and D‐Pro/Yeast could improve the growth performance of A. persicus.     

Determination of grapefruit (Citrus paradisi) peel extract bio‐active substances and its application in Caspian white fish (Rutilus frisii kutum) diet: Growth,haemato‐biochemical parameters and intestinal morphology

In this study, total phenolic and flavonoid contents of grapefruit peel extract (GPE) were equal to 117.3 ± 0.3 µg of gallic acid/mg and 39.30 ± 0.1 µg of quercetin/mg respectively. Caspian white fish (n = 180, 4 ± 0.9 g body weight) was fed with supplemented diets, including 0, 6.25, 12.5 and 25 mg of GPE/kg for 60 days at 25 ± 1°C. The growth performance was markedly improved in fish fed with 25 mg/kg of GPE compared to others (p < 0.05). Moreover, fish fed with 25 mg/kg of GPE showed a significant increase in red blood cell (2.65·10⁶ cell/mm³), white blood cell (17.75·10³ cell/mm³), packed cell volume (48%) and haemoglobin concentrations (8.75 g/dl) compared to the control (p < 0.05). However, the highest alanine aminotransferase (140 U/L), alanine transaminase (14.5 U/L), and alkaline phosphatase (18.5 U/L) were observed in control group. Morphological analysis of intestine revealed the highest amount of villus width (8.4 µM), height (32.86 µM) and surface area (342.7 µM²) in fish fed with 25 mg/kg of GPE (p < 0.05). In conclusion, supplementing feed with GPE at 25 g/kg can improve growth performance and haemato‐biochemical parameters of Caspian white fish fry.     

The antibacterial and antibiofilm activity of sea anemone (Stichodactyla haddoni) against antibiotic-resistant bacteria and characterization of bioactive metabolites

International Aquatic Research - Sea anemones produce many biologically active compounds including neurotoxins, pore-forming toxins, phospholipases and proteinase inhibitors. The Persian Gulf is an...     

The role of polychaete Nereis diversicolor in bioremediation of wastewater and its growth performance and fatty acid composition in an integrated culture system with Huso huso (Linnaeus, 1758)

This study was undertaken to evaluate the role of polychaete Nereis diversicolor in bioremediation of waste water and its growth performance and fatty acid composition in an integrated culture system with great sturgeon, Huso huso. Three treatments consisting of N. diversicolor fed with H. huso waste (FNW), N. diversicolor fed with fish feed waste (NW), and fish waste without the worm (FW) were considered at water temperature of 23°C for 8 weeks. The obtained results demonstrated that N. diversicolor in the flow‐through system could grow via feeding with the fish waste water. The pure production and survival rate of harvested Nereis in NW treatment were significantly higher than those of FNW treatment (p < .05). However, no significant difference was observed in specific growth rate and weight gain between these two treatments (p > .05). The highest removal efficiency of waste water including total nitrogen (56%), total phosphorus (53%), NO₂‐N (91%), NH₃‐N (35%)_, PO₄‐P (47%), BOD₅ (60%) were seen in FNW treatment. Also, the highest additional efficiency of NO₃‐N occurred in FW (37%) treatment. Certain fatty acids specifically 20:5 ω3 (eicosapentaenoic acid [EPA]) and 22:6 ω6 (docosahexaenoic acid [DHA]) were also abundant in Nereis, and analysis revealed some differences due to the diet. These results demonstrated that the promotion of growth by cultured Nereis can enhance the decomposition rate of organic matter in enriched sediment and minimize negative effects in fish farms. These results also suggest that the use of N. diversicolor is an excellent potential candidate for an integrated aquaculture and nutrient recycling including the removal of organic wastes.     

Bioresource Efficacy of Phosphate Rock,Sulfur, and Thiobacillus Inoculum in Improving Soil Phosphorus Availability

In order to improve the effectiveness of phosphate rock as phosphorus fertilizer, elemental sulfur and Thiobacillus have been evaluated as amendments. First, Thiobacillus was isolated from different soil samples. Then, a greenhouse pot experiment was conducted using a completely randomized factorial design with three factors included: elemental sulfur at four levels of 0, 1000, 2000, and 5000 mg kg^?1; phosphate rock at three levels of 0, 1000 and 2000 mg kg^?1; four Thiobacillus inoculums (T₁, T₂, T₃, T₄) and without inoculation (T₀) in three replications. Results showed that all the four Thiobacillus inoculums increased significantly extractable soil-P. Combined application of phosphate rock and sulfur in equal proportion (1:1) along with inoculum Thiobacillus had a significant effect in improving phosphorus availability in soil. Combined application of sulfur (at rates of 1000 and 2000 mg kg^–1) and Thiobacillus significantly increased phosphorus uptake by plants as compared to the control.     

Tunable functional properties on polyester fabric using simultaneous green reduction of graphene oxide and silver nitrate

Here, a novel method is introduced to create tunable properties on the polyester fabric through diverse chemical modifications. The polyester fabric was primarily modified with NaOH or ethylenediamine to enhance the surface activity. This will produce diverse chemical groups on the polyester fabric surface including carboxylate, hydroxyl and amine groups. The fabric was treated with grahene oxide through exhaustion method. The silver nitrate was then added and simultaneously reduced with grapheme oxide using ascorbic acid and ammonia to produce reduced graphen oxide/silver nanocomposites (rGO/Ag) on the fabric surface. The synthesized nanocomposites were characterized by TEM and Raman spectra. The presence and uniform distribution of the nanocomposites on the fabric surface was also confirmed by SEM images and EDX patterns. The electrical resistivity was varied on the raw and modified polyester fabric due to the diverse formation of the graphene nanosheets network on the fabric surface. More Ag particles were formed on the surface of the alkali hydrolyzed polyester whereas more graphene nanosheets deposited on the aminolyzed polyester fabric. Also the hydrolyzed polyester fabric exhibited higher antibacterial properties with the lowest silver nitrate in the processing solution. The aminolyzed fabric showed a lower electrical resistance than the hydrolyzed and raw fabrics with the same amount of GO in the procedure bath. The aminolyzed polyester fabric indicated higher affinity towards GO produced higher antibacterial properties before reduction and without silver nitrate however lower electrical resistance obtained after reduction comparing with other samples.     

Effects of exogenous dietary enzyme on growth, body composition, and fatty acid profiles of cultured great sturgeon Huso huso fingerlings

The effects of enzyme supplementation on growth, body proximate, and fatty acid composition of great sturgeon Huso huso fingerlings were investigated. Multienzyme (Kemin^?) was added to diet in different concentrations (0, 250, 500, 750, and 1,000 mg/kg). Fingerlings were randomly stocked in tanks and fed with the experimental diets three times a day at 5–10% body weight for 46 days. Fingerlings fed diets containing 250 mg/kg exogenous enzyme exhibited higher weight gain and specific growth rate. This level of enzyme in the diet significantly improved feed conversion ratio. Body protein and moisture decreased slightly when fish fed with enzyme-supplemented diets while fat increased. Fingerlings fed with 500 mg/kg enzyme in diet had higher contents of n-3 essential fatty acids and lower n-6/n-3 fatty acid ratio. Optimum growth performance in great sturgeon fingerlings can be obtained by 250 mg/kg multienzyme in the diet.     

Effect of dietary Ergosan on growth performance, digestive enzymes, intestinal histology, hematological parameters and body composition of rainbow trout (Oncorhynchus mykiss)

Present study examined the effects of Ergosan on growth performance, digestive enzyme activities, hematological parameters and gastrointestinal structure of rainbow trout. Rainbow trout (mean weight 100–110 g) were fed basal diet (control) and diet treated with Aquavac Ergosan (5 g kg^?1 of diet) for 50 days. Results of this study showed that Ergosan supplementation significantly increased weight gain (94.27 g vs. 65.04 g), specific growth rate (4.09 vs. 3.10) and feed intake (136.85 g vs. 111.22 g) and decreased feed conversion ratio (1.43 vs. 2.03) compared to control (P < 0.05). Lipase activity and leukocyte and erythrocyte count also increased in juvenile fish fed Ergosan-treated diet compared to control (P < 0.05). Light microscopy demonstrated that both groups of fish displayed normal morphology of proximal intestine and pyloric caeca. In Ergosan-treated group, higher percentage of goblet cell was shown in proximal intestine and pyloric caeca. Present study suggests that Ergosan effectively promotes growth performance, lipase activity and gastrointestinal structure in rainbow trout.     

Phosphorus Efficiency of Winter Canola Cultivars and Rhizosphere Properties in Rhizobox Technique

Production of oilseed crops requires balanced fertilization, while environmental problems of applied fertilizers must be considered. We evaluated seven winter canola cultivars (Brassica napus L.) for their relative efficiency to use or acquire phosphorus (P) under deficient and sufficient conditions. Average root mean diameter (RMD), total root length (RL) and root surface area (RA), of plants were measured as well as rhizosphere properties in rhizobox technique. Water-soluble P (WSP) and phosphatase activity of treatments containing plant were higher than control. WSP increased by 2.86 mg kg^?1 soil in Gabriela and 2.63 mg kg^?1 soil in Elvis at P deficient condition, compared to the control soil. The Olsen extractable P of the treatments decreased compared to control. Variations in total dry weights of cultivars were mainly explained by the differences in P solubilizing bacteria (PSB) population, pH, and phosphatase activity. The responsible mechanism for the P efficient (PE) cultivars can be higher P uptake through larger root and changes in rhizosphere properties.     

Investigation of Nitrate–Nitrogen (NO3–N) Mass Balance Between Effluent and Soil Under the Effect of Raw Pistachio Residues and its Biochar Application

Disruption in the nitrogen (N) cycle balance has a negative impact on the overall trend of sustainable development, and using soil amendments is necessary to reduce these hazards. This study was carried out as a factorial experiment in a completely randomized design. The treatments consisted of three levels of amendments (0, 7.5 g/kg of pistachio residues, and 7.5 g/kg of biochar) and four levels of irrigation water salinity including 0.5 (urban water), 5.5, 8, and 10.5 dS/m and in three replications. Two pistachio seedlings were transferred to all columns and then in three steps, and in each step, 25 mg N/kg of potassium nitrate was added. The results indicated that pistachio residuals and its biochar increased nitrate outflow from effluent by 9% and 52%, respectively. The effects of amendment treatment and irrigation water salinity on all three characteristics of output nitrate, soil nitrate, and absorbed plant nitrate were significant at 1% level.