فصلنامه فیزیولوژی و بیوتکنولوژی آبزیان
سال نهم شماره 2 (تابستان 1400)

In order to evaluate the presence or absence of DNA in cream and caviar extract samples, four samples of cream and one sample of caviar extract were evaluated for DNA concentration using Nanodrop and agarose gel analysis. The amount of DNA extracted in the samples of cream and caviar extract based on Nanodrop measurement was equal to 5 to 20 ng/µL, but it was not possible to examine these samples on agarose gel due to the little concentration. In order to test for the presence or absence of caviar extract and cream in the cosmetic cream, the mitochondrial DNA tracing method of sturgeon species was used by amplifying important fragments in global barcoding tests such as cytochrome oxidase I (COI) and cytochrome b (Cyt b). Amplified fragments in cream and caviar extract were analyzed by sequencing. The fragment length in COI gene was 650 nucleotides and in Cyt b was 1200 nucleotides. The final results showed that the cream and extract samples contain sturgeon DNA. The sturgeon species used to make the cream was closer to the Siberian sturgeon species (Acipenser baerii).

Consideration of marine organisms as potential sources of bioactive compounds and drug agents has increased in recent years. Skin is considered to be the largest and fastest growing organ in the human body and it plays the most important role in protecting of diseases and environmental factors. Due to the large surface area of the skin, it is sensitive to various diseases, including acne, dermatitis, and so on. Therefore, the present study was performed to evaluate the effect of brown algae phlorotannin extract and emulsion containing the extract against 6 pathogenic bacteria. Phlorotannin content was measured using phluoroglucinol reagent. Then, the antibacterial activity of the extract and its emulsion against 6 bacterial strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Propionibacterium acnes and Staphylococcus epidermidis were evaluated. The phlorotannin content was 13.94±0.29. The results showed MIC and MBC levels were lower in S. aureus, P. aeruginosa and P. acnes than in E. coli, B. subtilis and S. epidermidis, indicating the better performance of phlorotannin extract against them. Also, the emulsion containing the extract had a diameter of inhibition zone against P. acnes, E. coli, P. aeruginosa, B. subtilis. The results show that the formulation containing phlorotannin extract has potentials in the treatment of bacterial skin infections.

Tiger oscar (Astronotus ocellatus) is a favorite for aquarium fish enthusiasts due to its beauty and compatibility. The study was conducted to evaluate the effects of Lactococcus lactis and Bacillus subtilis on growth efficacy and hepatic enzymes of oscar by selecting 300 juveniles with a mean weight of 8.96±0.03g and length of 8.23±0.02cm. During 70 days fishes fed by diets contained L. lactis and B. subtilis in 9 single and combined treatments groups with the number 1010CFU/g bacteria in treatments which included 150, 300, and 450mg/kg of L. lactis (LL150, LL300, and LL450), 150, 300, and 450 mg/kg of B. subtilis (BS150, BS300, and BS450), 150, 300, and 450 mg/kg of an equal mixture of L. lactis and B. subtilis (MIX150, MIX300, and MIX450) and control group. Finally, their growth indices and hepatic enzymes were assessed. Results showed that applying both bacteria in the feeding of oscar fish has significantly improved the growth indices. Also, adding bacteria in the diet led to increased weight gain (WG), body weight index (BWI), average daily growth (ADG), Specific growth rate (SGR), final biomass and protein efficiency ratio (PER) compared to control (p < 0.05). All single and combined treatments compared to control had the most reduction of FCR which was statistically significant (p < 0.05). Also, the highest statistically significant difference between hepatic enzymes, alanine aminotransferase and aspartate aminotransferase was measured with control in treatment 3 (LL450) and alkaline phosphatase in treatment 9 (MIX450) (p < 0.05). The addition of these bacteria individually or in combination had a positive effect on growth indices and liver enzymes.

The anesthetic effects of Valeriana officinalis (valerian) and Cymbopogon citratus (lemongrass) extracts and Eugenia caryophyllata (clove) powder were examined on juvenile sterlet sturgeon, Acipenser ruthenus to determine their optimal concentration to evaluate the possibility of these extracts as a potential replacement for clove tree flowers. In this study sterlet juveniles averaged 86.2±11.7g in weight and 29.7±1.05cm in length were exposed to 45, 60, 75 and 90 mL/L valerian extract, 3, 5, 7 and 10 mL/L lemongrass extract and also 2000, 3500 and 5000 mg/L clove powder by immersion method. The Results revealed anesthetic effects of all three compounds on sterlet sturgeon. Considering the time required for anesthesia and recovery, the 60mL/L, 5mL/L and 3500mg/L doses were determined as optimum concentrations for valerian and lemongrass extracts and clove powder, respectively. Since the valerian and lemongrass extracts were very effective in inducing anesthesia in this study, their use as an anesthetic agent in aquaculture activities is recommended.

In this study, the effect of garlic essential oil on growth performance, hematological and biochemical parameters of goldfish (Carassius auratus) was studied. 180 goldfish with an average weight of 3.4±0.2g in four levels 0 (T0), 0.1 (T0.1), 0.15 (T0.15) and 0.2g (T0.2) of garlic essential oil per kg of diet (triplicate) were evaluated for 8 weeks. The results showed that growth performance and feed conversion ratio in experimental treatments respectively increased and decreased significantly compared to the control group (P<0.05). Hematocrit, hemoglobin and white and red blood cells in treatments containing garlic essential oil increased significantly compared to the control group (P<0.05). Garlic essential oil causes no significant effect on the parameters of MCV, MCH and MCHC (P>0.05). Blood protein levels in treatments fed with garlic essential oil increased significantly and blood glucose levels decreased significantly compared to the control group (P<0.05). Triglyceride levels in 0.2g/kg group were lower than other treatments (P>0.05). Also, there was no significant difference in alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) enzyme activity between experimental and control groups (P>0.05). The results of the present study show that the addition of garlic essential oil can be used as a useful dietary supplement to enhance health and biochemical indicators in goldfish.

The present study was designed to evaluate the effects of irradiated and non-irradiated Ergosan on growth performance, serum biochemical parameters and skin mucosal immune responses in crucian carp (Carassius carassius). Fish with a mean weight of 9.16±0.36g were randomly distributed among nine aquaria in triplicates and fed diets containing irradiated Ergosan at 30 kGy (1g.kg-1), non-irradiated Ergosan (1g.kg-1), or diet without any additives (control) for 40 days. Results showed that fish fed with irradiated and non-irradiated Ergosan had higher growth performance than the control (P<0.05). Mucosal biochemical parameters, including protein, glucose, cholesterol and triglyceride, were not altered by feeding treatment diets compared to the control (P>0.05). Digestive enzyme activities, including intestinal alkaline phosphatase and protease, increased with both Ergosan-treated diets, especially with irradiated Ergosan to the control (P<0.05). Skin mucosal lysozyme, alkaline phosphatase, and protease activities, also enhanced after administration of irradiated and non-irradiated Ergosan compared to the control (P<0.05). This study suggests that the supplementation of Ergosan, especially in irradiated form, could improve the growth performance, some digestive enzyme activities, and skin mucosal responses in crucian carp.

Symbiotic relationships play an important role in marine ecosystems. Among marine symbionts, marine dinoflagellate chemical compounds have drawn the interest of biologists and ecologists due to their rich supplies of unique active secondary metabolites. The aim of this study was to evaluate the cytotoxicity and antibacterial activity of Symbiodinium sp. extract isolated and purified from Stichodactyla haddoni in the Persian Gulf and the Gulf of Oman and purified and cultured Symbiodinium sp. in vitro. Sea anemone samples of S. haddoni were collected during summer and winter and Symbiodinium sp. was isolated from anemones by manual homogenization method and then cultured and extracted. Brine shrimp lethality test was used for investigation of Symbiodinium sp. extracts toxicity. The effect of extracts on human pathogenic bacteria, Escherichia coli and Staphylococcus aureus was also investigated. Results showed that the cytotoxicity of Symbiodinium sp. extracts during 24 and 72 hours showed the highest cytotoxicity in Chabahar summer with less LC50 (0.179 and 0.075 mg/mL, respectively). Comparison of antibacterial properties showed that the highest zone of inhibition was related to winter in Qeshm Island, but it was less than the penicillin zone. In general, the study of methanolic extracts did not show antibacterial properties, while they showed lethal effects on A. salina. Therefore, Symbiodinium sp. can be used as more specific anti-cancer and anti-tumor tests as a cytotoxic dinoflagellate.