جستجوی مقالات مرتبط با کلیدواژه « جلبک قهوه ای » در نشریات گروه « شیلات »

Nowadays, the use of immune supplements in aquaculture has become a serious need due to the high prevalence of diseases. For a long time, researchers have been interested in finding suitable, economical and environmentally safe immunostimulant. It is necessary to use these stimulants as feed or water additives to strengthen the immune system and increase resistance to challenging pathogens. Probiotics, prebiotics, plant extracts, micro and macroalgae and essential oils have been widely evaluated in aquaculture. Brown algae are a large group of algae that are widely distributed in marine environments. Fucoidan is a sulfated polysaccharide isolated from brown seaweed. Due to its numerous physiological and biological properties, it has attracted the attention of many researchers. Fucoidan extracted from brown algae has various biological functions, including anti-inflammatory, immunomodulatory, antitumor, antibacterial, antiviral, anticoagulant, antioxidant, and growth promoter. Given the biological functions of fucoidan, the present paper reviewed the effects on growth, antioxidant capacity and disease resistance in various aquatic animals.

This study was designed to evaluate the haemolymph immunological and antioxidant parameters in Penaeus vannamei fed on Sargassum ilicifolium hot-water extract (SHWE) supplemented diets. Three experimental groups including 0.25, 0.5, and 1% SHWE, and one control (without SHWE inclusion), each with three replicates, were applied. A totsl of 120 shrimps (4.67±0.08 g) were randomly distributed into 12 experimental tanks. At the end of a 66-day feeding trial, haemolymph immunological and antioxidant parameters were measured. The results indicated that alkaline phosphatase increased significantly in 0.25% SHWE fed treatment (p < /em><0.05). Glutathione peroxidase significantly increased in all the treatments fed the SHWE supplemented diets (p < /em><0.05). However, the levels of glutathione significantly increased in the groups fed by 0.25 and 0.5% SHWE supplemented diets (p < /em><0.05). The levels of glutathione s-transferase, superoxide dismutase, and catalase significantly increased in the treatment fed 0.5% SHWE supplemented diet (p < /em><0.05), whereas the total antioxidant capacity levels remained unchanged among the treatments (p < /em>>0.05). Both acid phosphatase and phenoloxidase did not influenced by dietary treatments (p < /em>>0.05). The levels of lysozyme were significantly lower in the treatment fed 0.25% SHWE supplementary (p < /em><0.05), whereas this experimental group did not show any difference with the others (p < /em>>0.05). The numbers of THC, GC, SGC, and HC significantly increased in the treatment fed 0.5% SHWE supplemented diet (p < /em><0.05). However, the fish fed 0.25% SHWE supplemented diet exhibited significantly higher THC and SGC levels, compared to the control group (P>0.05). The present results indicate that SHWE can be applied practically via a dietary route to boost the haemolymph antioxidant status as well as the cellular immunity of Pacific white shrimp.

At the present study, phlorotannin content, antioxidant properties (DPPH free-radical scavenging and ferric reducing power) and inhibitory of polyphenoloxidase enzyme from Vannamei shrimp (Litopenaeus vannamei) in different extracts (first and ethyl-acetate) extracted from brown seaweeds Nizimuddinia zanardinii, Sargassum ilicifolium, Sargassum cristaefolium and Stoechospermum marginatum with methanol 100% and 70% were investigated. Among different seaweeds species, the highest amount of phlorotannin (13.21 mg PHG/g), DPPH scavenging (72.64%) and reducing power (0.96) were measured in the ethyl-acetate extract of N. zanardinii in methanol 100% treatment. Phlorotannin compounds including Eckol, Dieckol, Bieckol were identified by using of TLC in the ethyl acetate extract of N. zanardinii. The results showed that phlorotannin content and antioxidant activity varies in different species depending on seaweed specie, type of extract and type of extraction solvent. The amount of Vannamei shrimp polyphenoloxidase inhibition was different between various extract and seaweeds; and the highest amount of inhibition (71.11%) was measured in the ethyl-acetate extract of N. zanardinii. The results of present study showed that seaweed extracts with high amount of phlorotannins content could be considered as natural and safe polyphenoloxidase enzyme inhibitor.

Sodium alginate is a cheap and available biopolymer due to its biodegradability and hydrophilic properties, PH sensitivity and natural nature received more attentions. Therefore, the present study investigates and compares the antioxidant properties of alginate in different concentrations of brown algae of Sargassum vulgare and Padina pavonica. According to the results, both algae had high antioxidant activity and the total amount of phenol antioxidant activity in three concentrations (100, 150 and 200 mg/ml), and chelating ability in three concentrations (0.1, 0.5 and 1 mg/ml) in Sargassum alginate were high. Ehereas the Padina alginate had a higher percentage of free radical scavenging DPPH, hydroxyl free radical at concentrations (0.11 and 1.83 mg/ml), regenerative power at the concentrations 160 and 320 µg/ml. There was no significant difference in the inhibition of free superoxide radicals between both algae at any concentration intervals(p <0.05).

The present study was conducted to evaluate the effects of oral administration of hot-water extract of the brown algae, Sargassum ilicifolium on the growth performance, digestive enzymes, and proximate composition in Penaeus vannamei. In this study, 600 shrimps with an average body weight of 4.7±0.55 g were distributed in 4 treatments with 3 replicates. Shrimps were fed a diet supplemented with 0 (control), 0.25, 0.5 and 1% hot-water extract. After a 66-day trial, the results showed a significant increase in the intestine and hepatopancreas amylase and protease activity of the shrimp fed with 0.25 and 0.5% hot-water extract. The intestine lipase activity was significantly lower in both treatments fed with 0.25 and 0.5% of the hot-water extract, while in the 1% treatment was significantly higher than in the control. The shrimps fed with 0.25 and 0.5% hot-water extract showed significantly higher hepatopancreas lipase activity than the control. The proximate composition analysis revealed no differences among the treatments with the control in the amount of fat, ash, protein, and moisture. The growth performance was also not influenced by the different amounts of supplementation. Although the growth parameters were not influenced by the supplemented fed diets, the enhanced enzymatic activity in the intestine and hepatopancreas may result in better efficiency in the prolonged feeding trial. It could be suggested that the use of the hot-water extract of S. ilicifolium as a natural supplementation without any adverse effects on the growth and proximate composition, could be beneficial in shrimp culture.

Brown algae are a valuable source of natural antioxidant compounds, especially Phlorotannins. In this study, the effect of solvent concentration (water / ethanol) on the the amount of Phlorotannin compounds and antioxidant properties of extracts from brown alga Sargassum angustifolium were investigated. The extraction was performed by solvent method at room temperature (28-26 °C) with ethanol/ water solvent with three ratios (30:70), (50:50) and (70:30). The amount of Phlorotannin, total phenolic content, ferric reducing antioxidant power, DPPH radical scavenging activity and total antioxidant capacity of different extracts were evaluated. The results showed that the yield of Phlorotannin extraction was dependent on the solvent concentration and with increasing polarity of the solvent, its amount increased, So its amount in ethanol/ water treatment (30:70) is significantly more than the other two treatments (P<0.05). Also, the highest amount of DPPH radical scavenging activity was obtained in ethanol/ water treatments 50:50 and 70:30 which contained less Phlorotannin. Finally, it was found that the ethanol/ water treatment 30:70 of the brown alga Sargassum angustifolium was a good choice for extracting Phlorotannin compounds as a natural bioactive compound for food and medicine purposes.

In this study, Sargassum angustifolium pigments were extracted by soaking method to identify process variables and optimize extraction conditions. In order to reduce the cost of extraction, RSM method and the optimal design with 3 independent variables and 5 replications at the central point (to calculate process repeatability) were completely randomized to determine the best combination of variables. Effective in the extraction process, chlorophyll a, total chlorophyll, total carotenoids and fucoxanthin were used. The results showed that the highest amount of fucoxanthin, total carotenoid and total chlorophyll was obtained in optimal conditions for 4 hours, 100% ethanol and 1:5 solid-liquid ratio. If the highest amount of chlorophyll a for 6 hours, 100% ethanol and a solid-liquid ratio of 1:10. The values ​​obtained in the experiment with the values ​​predicted by the software have logical relationships that indicate the appropriateness of the models used.

The extraction of hydrocolloids from seaweeds is associated with production of secondary metabolites during pretreatment step. In this study, the antioxidant properties were evaluated for secondary metabolites from brown seaweed S. angustifolium. The crude extract obtained by 80% ethanol for four hours and then partitioned using hexane, chloroform, ethyl acetate and water. The extraction yield was found to be 4% for crude extract and varied between 2.8-43% for fractions. The evaluation of antioxidant properties revealed a successful solvent fractionation in portioning antioxidant compounds. Among various fractions, ethyl acetate exhibited the highest activity in DPPH radical scavenging (75.78%), ABTS radical scavenging (88.92%), reducing power (67.54%) and total antioxidant (0.34 Abs) capacities. The highest amount of phenolic contents was found in ethyl acetate fraction (277.86 mg/ TA in extract) while the lowest amount was in aqueous fraction (21.36 mg/ TA in extract). The highest correlation (R2 = 0.88) was observed between total phenolic content and total antioxidant activity. Overall, the results of current study show that ethanol extract of S. angustifolium contains major bioactive compounds suggesting its potential application in food industry as a natural antioxidant.

Padina boergesenii is one of the most abundant brown algae distributed in the north of Persian Gulf and Oman Sea. In this study after sampling and preparation of Padina boergesenii by Chroform-Etanol (3-1) solvent and by Methanol has been extract. Separation and purification of the compounds was carried out using thin layer, general and inverse column chromatography, Cephadex and high performance liquid chromatography (HPLC). Structural elucidation of the constituents was based on the data obtained from H-NMR, 13C-NMR, HSQC, HMBC, DEPT and Cephadex LH-20. The steroids compounds separated from above alga were identified as 22-dehydrocholesterol (1), cholesterol (2), fucosterol (3), β- sitosterol (4), stigmasterol (5), ostreasterol (6) and two epimer of hyroxyestrol(7), based on their spectral data and from comparison with those previously reported in the literature.

This research has been conducted seasonally and in three stations so as to determine the dietary of sea urchin Echinometra mathaei species in tidal zones on Chabahar coast over the period of six month beginning from Shahrivar 1391 to Farvardin 1392 (Persion Date). The caught E. mathaei were delivered to yhe laboratory and after dissection، the contents of the digestive system of this species were examined through microscopes. The examination resulted in identification of the animals which were inside the digestive system and their priovitization in accordance with their species (brown، Red،Green Algea). The E. mathaei which has been under study has shown a various range of dietary. The fact that E. mathaei fed on brown algea (Kelp، Sargassum) and red algea (Grasylaria) has been pointed out by previous studies and this research also confirm the outcome of these studies. Because the study diet E. mathaei Sea urchin approx invertebrate animals cannot be classified as nutritional characteristics in vertebrates (fish) is used، enjoyed. Statistical indicators that can be used for sea urchin، gonadal index and calculate the total body weight is the weight of the gastrointestinal tract. On the whole، the dietary of E. mathaei consists primarily of brown algea available in their own habitat and secondry of red and green algea. It has also observed that they occasionally feed on Algea.

This study was performed to investigating distribution and biomass of two species of brown algae (Colpomenia sinuosa and Iyengaria stellata) in coastal waters of Hormozgan Province, Southern Iran. We sampled the algae over the years 2001 to 2002 in low tide periods using random 0.5 * 0.5 quadrats along a transect passing through six sampling stations.
The highest distribution extent of the two brown algae species during winter and spring seasons observed which coincided with the highest fluctuation in their biomass. The maximum biomass of C. sinuosa in winter and spring was 142 and 75 grams/m2 respectively. For I. stellata, the maximum biomass in the two seasons was 208 and 189 Grams/m2 respectively. Analysis of variance showed a significant difference among the biomass of the two algae species over different months and seasons of the year (p<0.05). Hence, we concluded that the species occurrence is seasonal and did not find a significant difference in the biomass of the two species obtained from different sampling stations. However, species appearance in different stations occurred in different months with the western stations showing a 1 to 2 months’ time lag compared to that of the eastern stations.

A series of research cruises were carried out in intertidal zones of Sistan-o- Baluchestan province in 1998. Four region of Gwatr, Chabahar, Tang and Galak were selected as sampling stations to collect samples from brown algae consist of: Sargassum glaucescens, Cystoseira indica and Nizamuddinia zanardini.This study was done monthly in one year period and recorded parameters were density, frequency and biomass.The results showed that the mean relative density of Sargassum in Gwatr, Chabahar, Tang and Galak were estimated 22.17, 8.48, 6.74 and 7.74 %, and for Cystoseira indica were 43.18, 11.95, 22.37 and 37.71%, respectively. The algae of Nizamuddin zanardinii was found only in two regions of Chabahar and Tang with 32.85 and 50.48% of relative density.
The minimum frequency of Sargassum was found from May to August and for Cystoseira Was from June to August with 12. 5q and for Nizamuddinia was in August-September with 0.0%. On the other hand, the maximum frequency for three species were recognized from October to February with 100.0% frequency for Sargassum and Cystoseira, and 50.0% for Nizamuddinia.
Also, the annual wet biomass in regions or Gwatr, Chabahar, Tang and Galak were estimated separately for each species consist of:- Sargassum glaucescens with 626.9, 117.8, 183.4 and 42.5 g/m2
- Cystoseira indica with 739.9, 95.2, 504.5 and 436.7 g/m2
- Nizamuddinia zanardini with 1352.2 and 1208.5 g/m2 in two regions of Chabahar and Tang.