AQUATIC PHYSIOLOGY AND BIOTECHNOLOGY
Year:2018 | Volume:6 | Issue:3|Papers Count:8

The black-lip pearl oyster, Pinctada margaritifera, is one of the important species of Mollusca which has been cultured to produce pearl. Mortality occurs in all stage of black-lip pearl rearing, but few studies have been conducted on this issue. The aim of this study is to investigate the pathogens of black-lip pearl oyster rearing site on Lengeh Port and also determine bacterial resistance and antibiotic sensitivity of the identified bacteria. Fresh samples were used for bacterial analysis. The bacterial analysis was done according to biochemical methods and bacterial Gram staining and using TSA and TCBS culture medium. Bacterial isolates were studied using Mueller Hinton Agar medium for the investigation of the resistance and antibiotic sensitivity of bacteria. Four different species of the genus Vibrio bacteria were found that Vibrio harveyi, Vibrio alginolyticus, Vibrio splendidus, Vibrio anguillarum were in the gills of black-lip oyster. Bacteria were resistant to ampicillin, erythromycin, streptomycin and oxacillin, sensitive to novobiocin, and intermediate to oxytetracycline.

In this study, the role of magnetic iron oxide nanoparticles (Fe3O4 NPs) synthesized using three methods of co-precipitation, conventional heating and microwave heating on the growth rate of Azolla filiculoides in aqueous solution was studied. In addition, effect of different iron oxide NPs on adsorption of Cd 2+ 2+ and Ni by Azolla was investigated. According to the results compared to control, the least growth rate of Azolla during 10 days was observed in the presence of the NPs synthesized using microwave method which majority of its particles were smaller than 10nm in diameter. Increasing concentration of NPs from 1000 to 2000ppm significantly reduced the Azolla growth. Presence of NPs changed the Azolla growth profile at 10 and 50° C, viz. the least growth of Azolla in presence and absence of NPs were observed at 50° C and 10 ° C, respectively. In addition, iron oxide NPs resulted in higher removal of Cd 2+ and 2+ Ni by Azolla, which was fitted to the first order kinetic model despite of reducing Azolla growth.

n this study, the effect of four levels of probiotic Pediococcus acidilactici on the diet of Astacus leptodactylus juveniles, on immunological parameters of hemolymph and enzyme systems, was investigated. Juvenile crayfish, weighing 10 to 20g, was fed in 4 groups of probiotic concentrations and one control group with three replicates for 84 days. At the end of the experimental period, the sampling of hemolymph in order to measure the hemolymph, immune and enzyme indices and crayfish intestines for digestive enzymes was performed. The results of all treatments and control showed that the highest to lowest homocysts belonged to semi-granitic, large granular and hyaline, respectively. The total number of hemocytes, semi-granular hemocytes, large granular hemocytes and hyaline in probiotic-treated treatments increased significantly compared to the control (P<0. 05). In addition, the activity of superoxide dismutase and phenol oxidase in the hemolymph of crayfish showed a significant increase (P<0. 05). Measuring the activity of digestive enzymes including lipase, amylase and protease showed a significant positive effect on all three enzymes (P<0. 05). Considering the positive and significant effects of probiotic P. acidilactici on immunological and digestive indices of young crayfish, it can be used to further increase in the productivity.

The aim of this study was to investigate the bioactivity of extract and enzyme hydrolysate extracted from Anodonta cygnea and Dreissena polymorpha. The powdered samples of soft parts of bivalves were used for the preparation of methanol, ethanol, chloroform extracts as well as enzyme hydrolysis. The antibacterial effects of these extracts were evaluated against gram negative Proteus vulgaris, Klebsiella pneumoniae and gram positive Enterococcus faecalis using disc diffusion method and measuring the growth inhibition zone. In addition, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the studied extracts were determined. Regarding the growth inhibition zone, the extracts and enzymatic hydrolysis of D. polymorpha showed greater antibacterial activity against P. vulgaris and K. pneumoniae compared to A. cygnea whereas A. cygnea was more efficient against E. faecalis. In conclusion, extracts and enzymatic hydrolysis of A. cygnea and D. polymorpha can be used as a valuable source with bioactive potential for producing antibacterial drugs.

Based on the various applicants of iron oxide nanoparticles (magnetite, Fe3O4-NPs) and their final entrance to aquatic ecosystems, the present study was conducted to investigate impacts of acute exposure (96 hours) of chemogenic Fe3O4-NPs (concentrations of 10, 100, 500, 1000, 2000 mg/L) and Bio-Fe3O4-NPs (500. 1000 mg/L) were biosynthesized by algae Ulva prolifera to changes in hematological indices including total and differential count of white blood cells (WBC), red blood cell (RBC) count, hemoglobin, hematocrit, RBC indices including MCV, MCH and MCHC, biochemical parameters including glucose and alkaline phosphatase (ALP), and immune responses including nitroblutterazolium (NBT) test in common carp (Cyprinus carpio) (average weight of 10. 04± 1. 83g) compared to the control group (without NPs). The results showed that, despite the no acute toxicity of both types of magnetite nanoparticles in common carp, with increasing concentrations of Fe3O4-NPs and BioFe3O4-NPs, a significant increase in hematocrit, hemoglobin, RBC, WBC (chemical type), glucose, and ALP, and a significant decrease in MCV and MCH were observed, while RBC was introduced as the most effective marker (rc = 0. 952, rb = 0. 982, P<0. 00001). However, at the same concentrations, the intensity of the changes in the indices in the exposed group to Bio-Fe3O4-NPs was lower than Fe3O4-NPs, which is probably due to differences in nature, synthesizing method and biocompatibility potential of Bio-Fe3O4-NPs.

In this study, the effects of spring viremia of carp virus (SVCV, Carp sprivivirus) with 4 10 TCID50 on liver enzymes including alkaline phosphatase, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase and blood biochemical parameters containing albumin, urea, fat, cholesterol, protein and glucose of Rutilus kutum were measured. The first clinical symptoms and mortality in intraperitoneal injection and bath trials were observed in 13 and 16 days post-treatment respectively. Liver enzymes in the bath and intraperitoneal injection treatments showed significant differences compared to the control (P<0. 05). The highest increase of the liver enzymes except alanine aminotransferase were observed in the bath treatment compared with the intraperitoneal injection. Some blood biochemical parameters including albumin and fat had significant differences in the intraperitoneal injection treatment compared with other treatments (P<0. 05). Urea, protein and glucose in the intraperitoneal injection treatments showed significant differences compared to the control (P<0. 05. ). Cholesterol showed significant differences among different treatments. The highest level of biochemical parameters was observed in intraperitoneal injection treatment. As a result, the SVCV able to make changes in liver enzymes, biochemical parameters and clinical signs, followed by mortality in the Caspian kutum fingerlings.

Understanding the role of salinity is importance on growth and survival of oriental river prawn and also enhancing its potential production. An experiment with salinities of freshwater (control), 6, 9 and 12 gL-1 was conducted for 8 weeks. 250 prawn juveniles with an initial average weight of 1. 5± 0. 44g randomly distributed between 15 glass aquaria of 100 liters. With increasing salinity levels up to gL-1, the growth performance and blood biochemicals including cortisol and glucose showed no improvment and had significant differences with other treatments (P<0. 05). Growth parameters such as BWI(%) and SGR in control treatment (0 gL-1-1 ) comparing with 6 gL were relatively increased without showing any significant differences (P>0. 05). However, the FER and SR in T1, T2, T3 and T4 (0, 6, 9 and 12 gL-1 ) showed no significant difference (P>0. 05). Some hemolymph biochemicals including cortisol and glucose were increased in T5 (16 gL-1 ) and the improvement was not observed (P<0. 05). This study indicated that the reared prawns have relatively better performance in freshwater.

The oil extraction step from the microalgae is considered to be the most important and essential step in the production of biodiesel. In this research, the effect of time on the ultrasound method was optimized in the pre-processing and extraction stages. Chlorella vulgaris microalgae pretreatment was carried out with methods of pretreatment with hot water and ultrasound radiation in water solvent. Extraction of oil was done by two methods of solvent extraction by ultrasound and Bligh and Dyer at certain times and specific solvent ratios, and its fatty acid profile was investigated. The results showed that pre-treatment of C. vulgaris microalgae had an effect on extraction efficiency and increased extraction rate. Also, using ultrasonic waves accelerates the process of mass and energy transfer, decreases the operating temperature and the size of the equipment. Using hot water with 15 minutes of ultrasound radiation in pretreatment and ultrasound extraction in 50 minutes increased extraction efficiency by 22. 96%, which were 18. 63% more than no pre-treatment and Bligh and Dyer. Investigating the composition and amount of fatty acids of C. vulgaris showed that ultrasound time has a significant positive effect on the amount of unsaturated fatty acids extraction.