فهرست مطالب

  • Volume:1 Issue: 1, 2017
  • تاریخ انتشار: 1396/01/14
  • تعداد عناوین: 7
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  • Akram Ahmadi, Hossein Riahi, Masoud Sheidai Pages 3-10

    The study of morphometric measurements of two morphologically similar charophytes, Chara vulgaris L. and Chara gymnophylla A. Braun from fresh water habitats can distinguish them from each other. Although both species differ in some characters but morphological differences are problematic when they co-occur in the same lakes, rivers or springs. Morphological differences given in identification keys couldn’t distinguish species and subspecies in the field. Therefore, additional characteristics were measured and suggested as useful features in differences of both species and their subspecies. Individuals of both species were collected in the vegetation seasons 2009 and 2013. Morphometric measurements and Statistical tests were done on 19 different quantitative and qualitative characters, number of branchlet corticated segments revealed the most significant difference. Branchlet/internode length ratio, characteristics of end segment: number of cells, number of corticated segments, end segment length were differed in Chara vulgaris and C. gymnophylla varieties. We applied these features as a useful morphometry characters for differentiation, particularly under conditions where both species co-occur.

    Keywords: Chara vulgaris, Charophytes, Chara gymnophylla, Identification, PCA, Morphometric Analysis
  • Shaghayegh Iranshahi, Neda Soltani, Taher Nejad satari, Shadman Shokravi, Mehroz Dezfulian Pages 11-20

    Cyanobacteria have a high morphological flexibility, so their identification is problematic. In this research, identification and morphological variability of indigenous cyanobacterium Anabaena sp. ISC 55 Bory ex Bornetet Flahault (Nostocaceae) is investigated disciplines-wide. For this purpose, soil samples were cultured in BG110 medium and Anabaena sp. ISC 55, after isolation and treatment with different pHs (5, 7& 9) and salinities (0, 1, 2, 3, 4& 5%), which then were followed biometrically and morphologically in solid and liquid medium via light and florescent microscope. Also, wall and cell variation was evaluated by scanning electron microscope (SEM). Morphological and molecular identification was carried out by valuable keys and 16s rDNA partial sequencing respectively. The results indicated that morphological variation of Anabaena sp. ISC 55 is dependent on the effect of pH and salinity. Biometric analysis implied that heterocyst and akinet shape is one of the most stable features and can be considered as a distinguishable character. The effect of pH is more highlighted in comparison to salinity. In salinities less than 1% and alkaline condition, optimum condition for colonization is prepared and clump shape of colonies can be considered as a stable character. Molecular identification confirmed the morphological one.

    Keywords: Anabaena, SEM, Morphological variation, pH, Salinity, 16s rDNA
  • Fereydon Mohebbi, Ahmad Ghoroghi, sohrab RezvaniGilkolaei, Hossein Riahi, Ali Nekoeifard, Masoud Seidgar Pages 21-38

    Today, harmful cyanobacerial bloom is considered as a main problem in freshwater ecosystems all over the world. The Microcystis is an important genus in cyanobacteria composed of about 23 species. This genusforms various shaped colonies including spherical or oblong cells which whole colony is surrounded by a mucilage sheath. Many populations and species of the genus produce sever blooms and often toxins in eutrophic freshwaters. The genus Microcystis has been defined based on morphological, morphometrical and genetical criteria, however, its classification under the genus level is still indistinct and presence of traditional morphological species within the genus is doubtful. Therefore, determining of the natural diversity under the genus level in Microcystis has a crucial importance. The purpose of this study was to determine the species of Microcystis in Aras reservoir. The samples were collected from 6 sampling sites on 18 August 2013. Morphological and morphometrical studies of Microcystis was carried out by Nikon 50i microscope equipped with Nikon DSFi camera and Nikon monitor with length measurment software. Principal Component Analysis (PCA) and two-way Unweighted Pair Group Method with Arithmetic Mean (UPGMA) byPAleontological STatistics (PAST) version 3.04 were performed to determine biosystematics variations between Microcystis populations. The results indicated that Microcystis from Aras reservoir was composed of two distinct groups based on the shape and size of cells, colony form, presence and absence of gelatinous sheath around the colonies, etc).These two groups may be considered as two morphospecies of M. botrys which are separated due to different ecological factors.

    Keywords: Microcystis, Morphology, Morphometry, Aras reservoir
  • MohammadReza Fatemi, Yousef Filizadeh, Farzaneh Rafiee, Behnam Daghoghi, GholamReza Arganji, Hossein Rameshi, Iraj Rajabi Pages 30-37

    The effects of some environmental parameters on biomass and agar yield of Gracilariacorticata were examined under laboratory conditions. The macroalga was collected from natural tidal pool with in Bostaneh coast (the Persian Gulf) in May 2004. In the laboratory, biomass and agar yield were measured after 45 days examining effect of different temperatures (24, 27 and 32°C), photon irradiances (24, 66 and 94 photons m-2s-1), and concentrations of ammonium phosphate [unenriched seawater (0), 0.04 and 0.08gl-1] in culture. Except for concentration of ammonium phosphate, other environmental variables showed no significant relationship (P>0.05) with biomass and agar content of G. corticata. The agar yield derived from the alga cultivated at 0.08gl-1 ammonium phosphate (22.40±1.81%) was significantly greater than the other treatments that makes G. corticata one of the commercial agarophytes (p<0.05).

    Keywords: Biomass, Temperature, Irradiance, Gracilaria corticata, Ammonium phosphate, Agar
  • Hosein Riahi, Zeynab Shariatmadari, Maryam khangir, Mehri Seyed hashtroudi Pages 39-46

    Cyanobacteria comprise a large group of structurally complex and ecologically significant gram-negative prokaryotes. There are many reports that these microorganisms produce phytohormones such as cytokinin, auxin and auxin-like substances in soil. Until now most research and applications of cyanobacteria have been conducted with green plants growing. There is no evidence to provide that cyanobacterial culture could stimulate mushroom growth and mushroom yield. In this study, algal culture of heterocystous cyanobacteria Anabaena vaginicola Fritsch et ich was sprayed on casing soil at primordia formation stage of Agaricus bisporus, before the first, the second and the third flushes. The result showed that inoculation of cyanobacteria into the casing soil as biofertilizer significantly increased mushroom yield and quality. In complementary studies, nitrogenase activity of this alga was determined by acetylene reduction technique and identification of phytohormones was performed with HPLC method. Chemical content of algal suspension was another factor that was analyzed in this experiment.

    Keywords: Anabaena vaginicola, Casing Soil, Phytohormone, White Button mushroom, HPLC
  • MOhammadMatin Hanifzadeh, Vahid Mortezaeikia, Omid Tavakoli, MohammadHossein Sarrafzadeh, Zahra Nabati Pages 48-54

    Power plants are considered a major contributor to carbon dioxide emissions. Moreover, flue gas of power plants contains other compounds such as NOx and SOx that can affect growth rate of microalgae. Therefore, in this study the effect of CO2 in different concentrations of 0.04%, 5% and 15%, NOx in 100ppm and SOx in 60ppm was investigated simultaneously on biomass production and carbon dioxide fixation of two industrially important microalgae, Chlorella vulgaris and Scenedesmus obliquus. At CO2 concentrations of 0.04%, 5% and 15%, the maximum CO2 fixation rate was 0.768, 0.73 and 0.69g/l/d for Chlorella vulgaris and 0.311, 0.53 and 0.212g/l/d for Scenedesmus obliquus, respectively. the results showed that at 15% of CO2, maximum CO2 fixation rate (RCO2) of Chlorella vulgaris was decreased from 0.69 to 0.65g/l/d by adding 100 ppm of NOx to culture medium, also a reduction from 0.69 to 0.212g/l/d was observed when 60 ppm of SOx was injected to CO2 stream. However, In the case of Scendesmus obliquus, an increase in RCO2 from 0.212 to 0.36 and 0.212 to 0.24g/l/d was achieved in the presence of the same amount of NOx and SOx, respectively. At the same culture conditions, Chlorella vulgaris shows higher fixation rate than Scendesmus obliquus. CO2 fixation rate increasing by Scendesmus obliquus in the presence of acidic gases (NOx and SOx) shows that Scendesmus obliquus tends to grow in lower pH.

    Keywords: Flue gas, CO2 Biofixation, Gaseous pollutant, Chlorella vulgaris, Scnedesmus obliquus
  • Razieh BaradaranGhafari, Mehrouz Dezfulian, Naser Harzandi Pages 56-60

    Industrial activity can cause the release of nickel into aquatic ecosystems with a negative impact on living organisms. Cyanobacteria have an important role in regulating pollution, reducting dissolved nickel in water, and increasing the mineral’s sedimentation. Recently the presence of phenylalanine ammonia lyase enzyme has been proved in cyanobacteria. This study aims to investigate the correlation between phenylalanine ammonia lyase activity and the rate of nickel absorption. For this purpose, a number of cyanobacteria Anabaena species, endogenous to Iran, were prepared by dry and wet treatment with nickel. The nickel uptake was evaluated by atomic absorption and comparison with a standard curve .The phenylalanine ammonia lyase was extracted from cyanobacteria and the enzyme activity was measured at different pH values. The results showed that some of the samples under study had remarkable ability to absorb nickel and that there were significant differences in the activity of the enzyme phenylalanine ammonia lyase at different pH values. This study established the relationship between the level of activity of this enzyme and the rate of nickel absorption.

    Keywords: Absorbtion, Nickle, Cyanobacteria, Ammonia-lyase