فهرست مطالب

  • Volume:3 Issue: 2, 2019
  • تاریخ انتشار: 1398/02/27
  • تعداد عناوین: 7
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  • Fatty acids components of marine macroalgae and their medicinal applications
    Jelveh Sohrabipour Pages 348-374

    Fatty acids (FA) are important nutritional substances and metabolites in living organism. Degenerative diseases related to inappropriate FA consumption form a potential death cause for two thirds of the population living in affluent, industrialized nations. Marine algae represent a considerable part of the littoral biomass. Many algal species have long been used as human food, animal fodder and source of valuable substances. In addition, algal components are of interest from a pharmaceutical point of view. Marine algae are rich in fatty acids (FAs) especially polyunsaturated fatty acids (PUFAs) and are of potential value as sources of essential fatty acids (n-3 and n-6 series),which are important in the nutrition of humans and animals. Also the n-6/n-3 ratio of macroalgae, because of their high n-3 content, is lower than 10 which is congruent with WHO recommended. Although each phylum of marine macrophytic algae has its characteristic FA pattern but up to now, only a limited number of algal species have been investigated for their FAs composition. Hence, the objective of this review is to explain briefly synthesis and structure of FAs and also to assess the potential of several Chlorophyta, Phaeophyta and Rhodophyta macroalgae as a source of FAs especially PUFAs and very long chain PUFAs (VLCPUFAs).

    Keywords: Fatty acid, Omega-3, Polyusaturated fatty acids, macroalgae, Chlorophyta, Phaeophyta, Rhodophyta
  • Hanie Younesi, Seyedeh Batool Hassani, AliAkbar Ghotbi Ravandi, Neda Soltani Pages 375-385

    Cyanobacteria are oxygenic, photosynthetic prokaryotes with unique potential to enhance plant growth, development, and productivity. The aim of this study was to evaluate the possible beneficial effects of Phormidium sp. ISC108 on seed germination, seedling growth criteria and photosynthetic efficiency of maize. Phormidium was applied to soil via irrigation whereas control group was irrigated via sterilized water. A significant promotion in the seed germination was observed in Phormidium treated Maize seeds. Similarly, Seedling growth indices of treated plants including biomass production, plant heights and leaf area significantly enhanced. Chlorophyll content as well as chlorophyll a fluorescence kinetics was also positively influenced by Phormidium application. Quantum yield of photosynthesis, primary photochemical reactions, rate of exiton transfer to electron transport chain, yield of electron transport and performance index of photosynthetic apparatus significantly increased in response of Phormidium application in soil. However, values of thermal dissipation of absorbed light showed a significant reduction as a result of Phormidium treatment. Considering remarkable growth promoting properties, Phormidium sp. may offer a feasible economical and environmental-friendly candidate as bio-fertilizer in sustainable maize production.

    Keywords: Biofertilizer_Chlorophyll a fluorescence_Cyanobacteria_Phormidium sp._Zea mays
  • Masoumeh Shams, sana Karimian Shamsabadi Pages 386-394

    Identification of algae of Shakh-Kenar, Gavkhouni Wetland, was studied from September 2017 to November 2018 at three stations with three replicate. A total, 69 species and 43 genera belonging to six divisions were identified. Species were belonging to the Bacillariophyta, Chlorophyta, Cyanophyta, Euglenophyta, Dinophyta and Chrysophyta. The density variations of the algae were between 98 and 1597 Cells/Cm3. The highest density was found at station 1 in the autumn. According to the Shannon-Weaver Index, the highest and the lowest diversity was observed in autumn and winter, respectively. Bacillariophyta, especially pennate forms; such as Navicula, Nitzschia, Cymbella, and Ulnaria were semi dominant in the most stations. From Chlorophyta; Pediastrum, Cladophora and Scenedesmus were showed conspicuous increase in summer and early autumn. Chroococcus disperses (Keissl.) Lemn, Merismopedia punctata Meyen, Oscillatoria sp. were demonstrated more abundance in autumn. Phacus sp., Euglena caudata Hubner, Trachelomonas playfair Defl., Glenodinium quadridense (Stein.) Schiller, Ceratium hirundinella (O. F. Muell.) Duj and Peridinium cinctum Muell., were observed in later summer and autumn. Regarding to taxa list, kind of pollution index algae and water quality index were recognized from Chlorophyta, Cyanophyta, Dinophyta and Euglenophyta, that they have an important role in changing of water odor/taste, blocking and corrosion of tubes and methods, and production of toxins.

    Keywords: Algae, Pollution bioindicators, Shakh-Kenar, Gavkhouni Wetland, Isfahan
  • Somayyeh Kheiri Pages 395-407

    Diatoms are the most diverse algae of the aquatic ecosystems and springs are of high value as the habit of high biodiversity and an important source of drinking for mankind. Therefore, study of the springs' algae flora is very important at the conservation view. In this research, the diatom biodiversity of the Tizab Spring and the spring-fed river was studied for the first time. Thirty species were identified of which one species (Achnanthidium gracillimum) is a new record for diatom flora of Iran. The data revealed that the flora is much similar to the Karaj River flora. This similarity can be due to the close geographical locations as both rivers are located in the Central Alborz region. The distribution pattern of the species were studied in Iran based on the present references on the Iranian aquatic ecosystems. This study presented that two-third of the species had a widespread distribution. The comparison of the flora with known European and American database showed that most species are the elements of the northern hemisphere. Diatom biodiversity studies in the Central Alborz region is in its first steps. Therefore, much research should be performed to reveal the diatom biodiversity and the potential new species in the region.

    Keywords: diatom, Central Alborz, distribution, Tizab, Spring
  • Fereidun mohebbi Pages 408-420

    Hypersaline environments are important natural assets of considerable economic, ecological, scientific and natural value. Management and protection of these changing ecosystems depend upon an understanding of the influence of salinity on biological productivity and community structure. The objective of the present study was to investigate the relationships between the two basic components in Urmia Lake i.e. microalgae and physico-chemical parameters, particularly salinity in order to provide a better understanding the dynamics of this unique ecosystem. 3 sampling sites were selected in north and south of Urmia lake. Samplings were carried out monthly from April 2018 to October 2019. In each site, 2 samples were taken for chemical, phytoplankton population analysis, respectively. The factors analyzed in each site were: water level, salinity, EC, TDS, pH, transparency Total phosphorus and total nitrogen (TP, TN), phytoplankton species composition and density. Statiscal analysis were performed by PAleontological STatistics (PAST) version 3.04. Totally, seven algal species were identified in Urmia Lake in this study. Bacillariophyta with 5 species was the most abundant algal group in the lake. Chlorophyta and Cyanobacteria both had 1 species, however, Dunaliella salina as the only representative of the green alga alone composed of about 99.5 percent of the total algal density of Urmia Lake. This study indicated that salinity, TDS and EC have the highest effects on the phytoplankton population structure and Dunaliella spp. Dominance in Urmia Lake. However, other factors such as TP and TN might have been masked by three main factors.

    Keywords: Phytoplankton, salinity, Urmia lake, hypersaline
  • Inhibitory effect of the brown seaweed Sargassum angustifolium extract on growth and virulence factors of Staphylococcus aureus
    Afsaneh Mohkami, Maziar Habibi Pirkoohi Pages 421-431

    Regarding the growing trend of multi-drug resistant strains of Staphylococcus aureus, the search for alternative and novel antimicrobial agent has been intensified. For this purpose, the present study was carried out to investigate the antagonistic effect of the brown seaweed Sargassum angustifolium on growth and virulence factors of S. aureus. A typical microdilution assay was performed to monitor inhibitory effect of the seaweed extract on growth of the bacteria within a 6-h period. Furthermore, Real-Time PCR assay with specific primers was conducted to evaluate the impact of seaweed extract on expression of the genes encoding staphylococcal enterotoxins (sea) and capsule formation (cap8). The results obtained in this research revealed that S. angustifolium extract inhibited bacterial growth in a dose-dependent way; so that bacterial growth was fully stopped at the end of the assay. Antibacterial effect was enhanced by increase in seaweed extract concentration. The results of Real-Time PCR assay indicated that the seaweed extract was able to decrease virulence genes expression significantly. Again, by increase in seaweed extract concentration, stronger inhibitory effect was observed. As a whole, the findings of this study suggest that S. angustifolium extract has potent antimicrobial effect that can be used for development of new generation of anti-staphylococcal medicines.

    Keywords: Antimicrobial, Seaweed, Staphylococcus aureus, Virulence factor
  • Latifeh Ahmadi Musaabad, Jamileh Panahy Mirzahasanlou, Mojtaba G.Mahmoodlu, Arsalan Bahlakeh Pages 432-442

    Springs are highly important habitats for biodiversity trend. Hence three springs in Golestan Province were selected for floristic study of diatom assemblages. Samples were collected seasonally from stony and sediment substrates. In total, 75 taxa belong to 38 genera were identified. Gomphonema and Nitzschia each with 7 species, Navicula with 6 sp. Surirella with 5 sp., and Cymbella with 4 sp. were the most species-rich genera. Results revealed that Gol-e-Ramian Spring with 61 taxa had the highest species richness. Achnanthidium nanum, Cocconeis placentula, Fragilaria crotonensis, Gomphonema micropus, Meridion circulare, Nitzschia vermicularis, and Planothidium frequentissimum were most abundant taxa. Most of the species identified in the present research have been observed within running water environments in Golestan province and other parts of Iran. Our study improved the knowledge of diatom communities in Golestan province springs.

    Keywords: epilithon, epipelon, Gol-e-Ramian, Nilberg