فهرست مطالب اسماعیل زارع مهرآبادی

Many marine invertebrates, such as sponges, produce secondary metabolites that have some pharmaceutical uses. This study was carried out to determine the antibacterial properties and the effect of seasonal variations on methanolic extracted from sponge Niphates furcata against Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus and Gram negative bacteria Escherichia coli and Pseudomonas aeruginosus using broth dilution method. The experiment results showed that methanolic extracts of sponge extracted in summer did not show any antibacterial effect on E. coli and P. aeruginosus and did not have the ability to inhibit the growth of the mentioned bacteria, and naturally the concentrations determined could not have any bactericidal effect on the gram-negative bacteria of E. coli and Pseudomonas aeruginosus. In winter, this extract had an inhibitory effect on all four gram positive and gram negative bacteria used in this study, In contrast to methanolic extract from summer, methanolic extract of winter season on Escherichia coli had a bactericidal effect, although it did not show any bactericidal effect, similar to that of summer on Pseudomonas aeruginosus. Comparison of the data shows that the methanolic extract of Niphates furcata sponge has a more severe inhibitory effect on the bacteria than in the winter, although the comparison of the bacterial pathogenic effects in both summer and winter shows similar results, and the concentrations have not shown any bactericidal effect on Pseudomonas aerosinosis.

The presence of nanoparticles affects the physiological condition of fish and reduces the immune function of fish, so the use of immune stimulants such as molasses is very important. 250 juveniles of common carp for 42 days in four categories: ration without molasses (treatment 1), ration containing 0.5% molasses (treatment 2), ration containing 1% molasses (treatment 3) and ration containing 2% molasses (Treatment 4) were divided. Then, 50% of the lethal concentration of nano-iron was added to each group for fourteen days. Histological studies of fish exposed to molasses and iron nanoparticles showed structural abnormalities in liver tissue. So that these changes were very different compared to the tissues of the control group. The final conclusion of the present study showed that nano-iron treatment led to tissue damage in carp liver; Although histopathological complication was also observed in the combination of nano-iron and molasses treatments, but the severity of injuries decreased with increasing molasses concentration. The negative effect of iron nanoparticles on normal carp liver tissue by molasses seems to be minimized.

The aim of this study was to investigate the effect of different prebiotic levels of oyster mushroom (Pleurotus ostreatus) on hematological indices of Nil tilapia exposed to silver nitrate. For this purpose, 120 juveniles of tilapia were fed with diet containing 0 (treatment 1, control), 0.05 (treatment 2), 0.1 (treatment 3) and 0.2% (treatment 4) prebiotic oyster mushroom) for 42 days. Then, 0.5ppm of silver nitrate was added to each group for 16 days. Before and after exposing to silver nitrate, fish blood indices were evaluated. Prebiotics alone had no significant effect on RBC, MCV, hematocrit and hemoglobin (P<0.05). But, treatments fed with prebiotics and exposure to silver nitrate toxin showed an increase in WBC, MCHC (in 0.1 and 0.2 treatments), MCH indices compared to the control group. According to the results, oral prebiotics stimulated nonspecific immunity in tilapia and using mushroom prebiotics reduced the destructive effects of the silver nitrate toxin on blood indices. In conclusion, levels of 0.1 and 0.2% of prebiotic oyster mushroom in treatments which exposed to 0.5ppm silver nitrate toxin could improve the blood factor status of tilapia.