فصلنامه فیزیولوژی و بیوتکنولوژی آبزیان
سال دهم شماره 3 (پاییز 1401)

The formation of microbial biofilms is one of the key steps in marine fouling. Therefore, the development of anti-biofilm strategies, especially through research on environmentally friendly antifouling materials, can help control biofouling. The present study was performed to evaluate the antibacterial and anti-biofilm activity of carvacrol and eugenol against marine bacteria isolated from Persian Gulf waters. In disk diffusion method, Vibrio sp. (KM1) bacteria showed more sensitivity against carvacrol and eugenol with a growth inhibition zone diameter of 17±0.3 and 15±0.5mm, respectively. Minimum inhibitory concentration (62.5µg/mL) and minimum bactericidal concentration (125µg/mL) were also obtained with carvacrol against KM1. In this study, the inhibitory effect of carvacrol and eugenol on biofilm formation by Pseudoalteromonas sp. (PH18) using tissue culture plate method (TCP) was investigated and 4MIC concentration showed the highest biofilm inhibition (carvacrol 90% and eugenol 87%). Based on the results, carvacrol and eugenol can be used as an alternative in antifouling coatings due to their appropriate anti-biofilm activity against marine bacteria.

Siberian sturgeon (Acipenser baerii) grows rapidly in breeding ponds. Gynogenesis is a suitable technique for producing sturgeon female sex. The aim of this study was to establish female sex in Siberian sturgeon using induction of gynogenesis. The sperm of Persian sturgeon (Acipenser persicus) was genetically inactivated by UV radiation at a dose of 8514 J/m2. In this case, sperm with 40% motility were combined with Siberian sturgeon oocytes and in 2°C cold shock for 30 minutes, 10 minutes after activity, gynogenic progeny were created. Fertilization rate was 44.5% (control hybrid 62%) and hatching rate was 19.8% (control hybrid 40.5%). Purely maternal heritability in gynogeneic progeny was confirmed using microsatellite markers. By achieving the biotechnique of sperm production with inactivated DNA of Persian sturgeon, it is possible to prevent the risk of extinction and protect other sturgeon by inducing gynogenesis.

The aim of this study was to evaluate the effect of short-term feeding of turmeric (Curcuma langa) and black pepper (Piper nigrum) on blood and immune parameters and liver enzymes of rainbow trout (Oncorhynchus mykiss) during 30 days. A total of 450 fish with an average weight of 24.95±0.70g were selected and in ten experimental groups, fed with diet containing turmeric (C) and black pepper (P) in a combined ratio (R) of 30, 50 and 70% at levels (L) of 0 (control), 0.25, 0.5 and 1%. Parameters with independent effect including AST at the level of 0.25%, lysozyme and complement at the level of 0.5% and RBC and hematocrit at the level of 1% had the highest levels. The highest amount of hemoglobin, total protein and the lowest amount of triglyceride and cholesterol were reported in the higher ratio of black pepper to turmeric (30%C + 70%P) at the level of 1% of plant supplement. The highest amount of globulin and total immunoglobulin was observed at the level of 0.25% of the diet and the combined ratio of 70%C + 30%P. Improvement of these parameters can be due to the positive effect of turmeric and black pepper combination on the immunity of rainbow trout. Therefore, it can be suggested that the 1% herbal supplements be used in the diet of rainbow trout.

In this study, the effects of various concentrations (5, 10, 50, 100 and 200mg/L) of copper oxide (CuO) and iron oxide (Fe2O3) nanoparticles (NPs) on growth, lipid peroxidation and activity of catalase and ascorbate peroxidase enzymes were investigated. The results showed that concentrations of more than 5mg/L of CuO-NPs and more than 10mg/L of Fe2O3-NPs reduced the growth of Nannochloropsis oculata. The content of aldehydes in response to some of concentrations of both metal oxide nanoparticles significantly increased compared to control (P<0.05(.  However, the increase of aldehydes in response to CuO-NPs was higher than Fe2O3-NPs. The activity of ascorbate peroxidase increased significantly in response to both nanoparticles, but the effect of CuO-NPs on the activity of this enzyme was higher than that of Fe2O3-NPs. Catalase activity showed a significant increase in response to CuO-NPs, but Fe2O3-NPs decreased the activity of this enzyme. The results showed that the toxicity of CuO-NPs in N. oculata was much more severe than Fe2O3-NPs.

This experiment was conducted to evaluate the effect of different levels of supplementation of Sargassum ilicifolium on the growth performance, blood parameters and digestive enzymatic activities of goldfish (Carassius auratus) for 60 days. Goldfish (with an average initial weight of 5.25±0.45g) were divided into four experimental treatments with three replicates (30 fish/replicate) inluding control treatment (without algae extract) and three treatments supplemented with Sargassum extracts 5, 10 and 15g/kg diet. The results showed that the highest final weight, weight gain, specific growth rate and condition factor were observed in fish fed with 15g/kg S. ilicifolium extract. Hemoglobin and MCH in fish fed with diets containing S. ilicifolium extracts showed significant difference compared to control group. The levels of triglyceride and cholesterol in fish fed with control diet were significantly higher than that of fed diets containing S. ilicifolium extracts (P<0.05). The highest proteases, amylase and lipase activities were recorded in Sargassum extract at 15g/kg diet. The results of this study showed that goldfish fed the diet containing 15g/kg S. ilicifolium had better growth performance and activity of digestive enzymes compared to other groups. Therefor the administration of 15g/kg of S. ilicifolium extract is recommended to use in goldfish diet.

Endophytes play an important role in protecting plants. In this study, endophytic combination of Aspergillus niger and Bacillus aquimaris OD14 was used to improve tolerance of Mexican lime seedlings to salinity stress. Three months after inoculation, salinity stress of 0, 2000, 4000 and 6000 μs/cm was applied. After 8 weeks, morphological, biochemical and elements adsorption traits of seedlings were evaluated. The experiment was carried out as factorial in a completely randomized design with three replications. The results showed that in 6000 μs/cm water salinity, endophytic compound increased stem length (103.64%), trunk diameter (103.04%), number of leaves (444.41%) and root length and width (232.02% and 41.63% respectively). Endophyte increased 76.29% of SPAD chlorophyll content compared to control. Also, the uptake of root potassium (34.95%) and shoot calcium (115.15%) increased and the uptake of sodium elements was decreased (29.49%) compared to control. Endophytic combination could significantly reduce ion leakage (65.57%) and increase proline content (69.3%) in inoculated seedlings compared to control. In general, marine endophytes can be used as a suitable option to increase plant tolerance to salinity.