p. akbary

The aim of this investigation is to evaluate the effects of Artemia urmiana metanauplii enriched with a premix extract of brown macroalgae including Padina australis, Sargassum ilicifolium, and Stoechospermum marginatum (macroalgae premix extract; MPE) on growth performance, survival, carcass quality traits, and antioxidant properties of Litopenaeus vannamei (PL15). A total of 1200 PL1(19±0.97 mg) were randomly divided into 4 groups (100 individuals in each group (in triplicate)). The control group was fed only with non-enriched metanauplii (MPE0) and other groups were fed with metanauplii enriched with 200 (MPE200), 400 (MPE400), and 600 (MPE600) mg L-1 for 15 days. Our findings revealed that the highest specific growth ratio (SGR), percentage weight gain (WG), protein efficiency ratio (PER) and dry matter were recorded in the group fed with MPE600-enriched metanauplii. The feed conversion ratio (FCR) in the group fed with MPE600 was less than in other experimental treatments (p<0.05). The highest levels of polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid(ARA), total sterols, and total amino acid content were observed in the shrimp fed with metanauplii enriched with MPE600 (p<0.05). The phenol, flavonoid, superoxide dismutase (SOD), and catalase (CAT) contents were increased by increasing levels of MPE in themetanauplii diet (p<0.05). This study demonstrates the positive effect of metanauplii enrichment with 600 mg L-1MPE on growth performance, carcass quality, and antioxidant properties of L.vannamei.

The extraction method and particularly the type of solvents used in the procedure are one of the most crucial steps for isolating antimicrobial compounds and extracts that potentially affect various microorganisms. This study aimed to evaluate the effects of water, ethanol (100%), methanol (100%), ethanol-water (50:50), and methanol-water (50:50) burdock (Arctiumlappa) root extracts (BE) on total phenol content and polyphenols as well as the antioxidant activity. In the next step, the solvent with the highest efficiency to have phenolic compounds were selected and employed to investigate the antibacterial effects of BE on the pathogenic bacterial strains (i.e. Yersinia ruckeri, Lactococcus garvieae, Pseudomonas putida and Aeromonas hydrophila) in rainbow trout (Oncorhynchus mykiss) by using disc diffusion test and tube dilution techniques. Maximum mean total phenolic content and antioxidant capacity were detected in the water-methanol mixture. Additionally, High-performance liquid chromatography(HPLC) analysis revealed that both hesperidin and trans-ferulic acid compounds existed in all solvents. The antimicrobial activity of water-methanol BE was varied based on the type of microorganism. In this context, Y. ruckeri as a gram negative bacterium was found to be the most susceptible one compared to other pathogens. According to our findings, water-methanol solvent was more efficient to isolate phenolic compounds and exert antioxidant capacity, as the level of phenolic compounds in the extract was increased. Moreover, Y. ruckeri was recognized as the most sensitive pathogen in all tests.

Microalgae contain many valuable biological compounds, so their commercial production is of great importance. One of the important challenges in microalga production is their high cost associated with their harvesting processes. Therefore, finding efficient and cost-effective technologies for algae biomass separation is essential for achieving an operational process. The study was conducted to find the influence of pH variation from 4 to 11 on harvesting efficiency and fatty acids component of marine microalgae Thalassiosira sp under laboratory condition. The NaOH and HCl were added to adjust pH value in each treatment. Data was presented as mean ± SD. Comparison between treatments was performed using one-way analysis of variance ANOVA. The results showed that with increasing the pH up to 10, flocculation processes (92%) and concentration factor (20) increased significantly. While, lowering the pH from 8.2 to 4 was not effective in isolating algal biomass. In the next stage, the biomass fatty acids content was measured by both alkaline pH induction method and the centrifuge method. Analyzes showed that the percentage of lipid and saturated and unsaturated fatty acids in biomass collected by alkaline pH induction technique was lower than the centrifugation method. In general, the results of the present study showed that clotting in alkaline pH up to 10 can be suggested as a suitable method for harvesting of Thalassiosira sp microalgae, and if the production of polyunsaturated acids is considered, of consuming high amounts of sodium hydroxide should be avoided.

This study was conducted to evaluate the effect of aqueous Zingiber officinale extract (ZE) on growth performance, antioxidant activity and resistance of shrimp (Litopenaeus vannamei) challenged with Photobacterium damselae bacteria. A total number of 600 post larvae shrimps (initial weight, 1.06±0.7 g) were randomly distributed into 12 fiberglass tanks representing four treatments each tank containing of 50 shrimp. The control shrimp group (ZE0) was fed a ZE free basal diet. Other groups were fed the basal diet supplemented with 0.5 (ZE 0.5), 1.0 (ZE1) and 1.5 (ZE 1.5) g kg-1 diet. Diets were offered to shrimp at a feeding rate of 10% of live body weight for 8 weeks. After 8 weeks of experimental trial 30 shrimp from each group was infected with LD70 bacteria P. damselae over 10 days to evaluated disease resistance of infected shrimp. Results revealed that growth performance (WG, SGR, FW and PER), the antioxidant activity (SOD, PO, GPx and CAT) of shrimp have significantly increased and cumulative mortality rate decreased (p<0.05) in the ZE1 group compared with the other groups. Meanwhile, the lowest FCR and MDA value were observed in shrimp fed ZE1 supplemented diet. It can be concluded that Z. officinale extract at the level of 1g kg-1 (ZE1) diet seems to be the most appropriate level for increasing growth performance, antioxidant activity and disease resistance of L. vannamei.

This research aimed to assess the effect methanol extract from Padina astraulis (Hauk , 1887) on biochemical response and digestive enzyme activities in grey mullet, Mugil cephalus (Linnaeus, 1758). A control diet without and three other empirical regimens were prepared with the addition of of P.astraulis extract (PE diet) at the incorporation levels of 5, 10 and 15 g kg-1 diet, respectively. Three hundred sixty grey mullet with an introductory mean weight of 0.82 g were randomly dispersed into twelve fish tanks and fed twice a day (09:00 and 17:00) for 60 days. After 60 days of the feeding trial, no significantly different was noticed in terms of survival rate between control and the groups supplemented with PE (p>0.05). Dietary PE significantly increased serum total protein, globulin levels and amylase, lipase and protease enzyme activities in treated fish (p<0.05). Moreover, there was considerable decline (p<0.05) in cholesterol, glucose and triglyceride levels in those fish which received PE diet over the control. The current research illustrates the appropriateness of P. astraulis extract as a novel dietary additive in grey mullet diet for improving metabolism of lipid and carbohydrate and enhancing digestive enzyme activities in grey mullet.

The present study was investigated on effect of optimum dietary level of Chlorella vulgaris powder (CP) as a feeding supplement on various blood biochemical criterion (Cholesterol (CHO), triglyceride (TG), total protein (TP), glucose (GLU), and lysozyme) and digestive enzymatic activities (amylase, lipase and protease) of the grey mullet (Mugil cephalus L). Four experimental regimens were supplemented with CP at 0, 5, 10 and 15 g kg−1 diet (CP0, CP5, CP10 and CP15). Number of twelve pools (60-L) with three duplicates for analysis groups (n=10 per pool with initial weight average 14.95±2.01 g) and the control group were studied. Upon 60 days of the feeding trial, fish fed CP5 diet had lower serum CHO and TG levels than fish fed CP0, CP10 and CP15 diets (p<0.05). No considerable difference were found in GLU when comparing fish fed CP5 and CP10 diet (p>0.05). Most serum total protein and amylase, protease, lipase and lysozyme activities were observed in fish fed CP5. Also, fish fed CP10 and CP15 diets had higher digestive enzymatic activities, serum total protein and lysozyme activities than fish fed CP0 (p<0.05). The outcomes proved the inclusion of 5g chlorella powder dietary supplementation in the commercial regimen may improve the blood chemical responses and the activity of digestive enzyme in grey mullet.

The primary aim of the current study has been to examine the impacts of dietary supplementary of Chlorella vulgaris (Beijerinck) powder (CP) different levels on the anti-oxidant enzyme activities, growth, and immune responses of the juvenile Mugil cephalus (Linnaeus). Experimental Fish (15 ± 0.1g) was fed diets enriched with 0 (control), 5, 10, and 15 g CP per kg feed for eight weeks period. After the feeding trial period, the fish were challenged against pathogenic bacteria (Photobacterium damselae (subsp. piscicida)) for evaluating the resistance of infected fish to diseases. According to the results, fish growth performance was significantly improved with increasing CP levels at CP10 and CP15. Antioxidant-stimulated activity was observed with dietary CP where total antioxidant capacities (TAC), glutathione (GSH), and super-oxide dismutase (SOD) augmented, while malondialdehyde (MDA) decreased significantly in fish fed CP. Furthermore, serum lysozyme activity of fish fed three levels of CP has been considerably enhanced in comparison with the control group (p <0.05). Moreover, CP supplementation at 10 and 15 g dose induced kidney phagocyte and respiratory burst activity which was maximized at 15 g CP. Meanwhile, feeding 10 and 15 g of CP diets decreased mortality in M. cephalus after challenge with P. damselae.  The present study indicated the role of optimal doses Chlorella vulgaris extract (10 and 15 g kg -1 feed) on growth and antioxidant defense and immune status of grey mullet.

This study aimed at determining impacts of various amounts of water-soluble poly-saccharide extracts from brown algae, Padina australis (Hauck) (WPP) on actions of anti-oxidant enzymes, the growth, and non-specific immune response of shrimp, Litopenaeus vannamei (Boone). Triplicate groups of shrimp (1 ± 0.1g) have been given feed 4 iso-nitrogenous and iso-lipidic diets composing of 4 levels; that is, 0 (control), 0.5, 1.0, and 1.5 g kg-1 of WPP extract for eight weeks. Analyses showed that significantly positive effects of diets with 1.0 g kg-1 of WPP extract on the growth function of the studied groups. Additionally, improvements of the anti-oxidant enzyme activities, such as catalase, malondialdehyde, super-oxide dismutase, and glutathione peroxidase via feeding 0.5 and 1 g kg-1 of WPP extracts. Furthermore, activity of phenoloxidase and lysozyme in the treatment fed by 0.5 and 1 g kg-1 of WPP extract have been considerably greater in comparison to the controls and 1.5 g kg-1 treatments. Findings demonstrated that usage of 1.0 g kg-1 of water soluble poly-saccharides extract of the P. australis are useful on growth function, antio-xidant and non0specific immune variables of the L. vannamei.

The present research was aimed to assess the effect methanol extract from Ulva rigida on biochemical response and digestive enzyme activities in Mugil cephalus. A control diet without and three other experimental diets were supplemented by U. rigida extract (UE diet) at the inclusion levels of 5, 10 and 15 g kg-1 diet, respectively. One hundred and twenty grey mullets with the mean weight of 14.95 ± 2.01 g were randomized into 12 tanks and fed twice per day (09:00 and 17:00) for 60 days. After 60 days of the feeding trial, serum total protein and globulin levels of the fish receiving UE diet had incremental trend and better performance, except for samples fed UE5. The UE10 diet resulted in the highest amylase, lipase and protease activities. Significantly different was observed in survival rate, glucose and triglyceride levels between control and UE supplemented groups (p< 0.05). There was significant reduction in glucose and triglyceride levels in the fish received UE diet compared to the control (p<0.05). According to the present results, U. rigida extract as a new introduced dietary supplement is suitable for improving metabolism of carbohydrate and enhancing digestive enzyme activities in grey mullet.