فهرست مطالب

  • Volume:1 Issue: 2, 2017
  • تاریخ انتشار: 1396/02/05
  • تعداد عناوین: 7
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  • Growth, Pigmentation, Photosynthesis and Morphological Characterization of Crude Oil degrading Cyanobacterium Phormidium sp. ISC104
    Fariba Amirlatifi, Neda Soltani, Sara Saadatmand, Shadman Shokravi, Mehruz Dezfulian, Mehdi Bolfiion Pages 63-71

    The marine environment is highly susceptible to pollution by petroleum, so it is important to understand how microorganisms degrade hydrocarbons. In this research the effects of crude oil on morphological and physiological characterization of the cyanobacterium Phormidium sp. ISC104 were investigated. With respect to the physiological responses, cyanobacterium optimum growth was observed in 1% crude oil. The most of chlorophyll content was observed in control sample. Phycobiliproteins had the highest rate in 1% crude oil. According to biodegradation, the results suggested that Phormidium sp. ISC104 can reduce oil content by 24.54 and 43.82% after 14 and 28 days respectively. In morphological point of view, dimensions of cells were not significantly impressed, although a slightly decrease was observed in 5 and 7% crude oil in comparison to control. This study demonstrated that crude oil doesn’t have destructive effect on cyanobacterium Phormidium sp. ISC104 up to 1%, indicating the potential of this cyanbacteriumin biodegrading this pollutant.

    Keywords: Biodegradation, Morphology, Oil pollution, Phormidium, Physiology
  • Fatemeh Heidari, Hossein Riahi, Zeynab Shariatmadari, Morteza Yusefzadi Pages 72-81

    Hot springs have been a subject of intense discussion for biologists in the last decades. The polyphasic approach is the most progressive system that has been suggested for distinguishing and phylogenetically classifying cyanobacteria. In a revision of the cyanobacteria in hot springs of Iran, four hot springs of Iran were investigated. We developed a combined molecular and morphological approach to identification of cyanobacteria. In this study seventeen populations and 13 morphological characters were analyzed. Molecular study based on 16S rRNA gene sequence does not disrupt morphological information and it confirms the separation of studied taxa according to morphological characters. Based on their growth characteristics; seven species were selected for the production of antimicrobial agents. The results of this study showed that the methanol extracts exhibited high antimicrobial activity against some gram positive bacteria, moderate antibacterial activity against some gram negative organisms and moderate antifungal activity against some fungi. Four species were selected for salinity tolerance. The results showed high tolerance of these taxa to salinity.

    Keywords: Cyanobacteria, Hot Spring, Morphological Diversity, 16S rRNA, Polyphasic study
  • Dried Seaweed (Sargassum ilicifolium) as an Adsorbent for Phosphorous Removal from Aqueous Solutions
    Mahmoud Hafezieh, Morteza Hosseini, Hamidreza Rezaii Pages 82-92

    Aquaculture is a source of significant amounts of wastes, which generally leads to deterioration of water quality. Removal of phosphorous (P) from aquaculture wastewater is an important environmental challenge. In the present study, efficacy of dry sea weed (Sargassum ilicifolium) to remove water P was investigated under laboratory conditions. Several levels of medium pH (3.5-10), initial P concentration (0.015-0.45mgl-1), contact time (7-60min), particle size (0.5-5mm) and the sea weed particle concentration (10-40gl-1) have been monitored. The results showed a high efficiency of the sea weed to remove water P under different conditions (83.1-97.7% P removal). Among the tested pH, 3.5 had the lowest P removal. P removal linearly increased along with time progress. The lowest P removal was observed in the lowest initial P concentration (0.015mg/l), however, there was no significant difference among the groups with initial P concentration of 0.15-0.45 mg/l. P removal in 10g/l sea weed concentration was significantly lower than those of 20 and 40g/l. P removal significantly increased with decrease in sea weed particle size. Regression analysis showed that the weight of factors to remove P from the medium was as follow: particle size (β = -0.659)> particle concentration (β = 0.427)> time (β = 0.227)> initial P concentration (β = 0.190)> medium pH (β = 0.113). In conclusion, dry S. ilicifolium is capable to efficiently remove P from wastewater at aquaculture-relevant concentration. The P removal capability of the seaweed markedly increases by decrease in particle size and increase in particle concentration in medium.

    Keywords: Uptake, Phosphorus, Wastewater, Seaweed, Adsorption
  • Yousef Ali Asadpourosalou, Fereidun Mohebbi, Masoud Seidgar, Fakhri Ghezelbash Pages 94-102

    The effects of water physico- chemical factors on phytoplankton communities of Shahrchai dam reservoir were studied. 6 sampling sites were chosen along Shahrchai dam and surface and deep layers were sampled during 3 seasons in 2015-2016. In this study, phytoplankton samples were fixed with 4% formalin and transferred to laboratory. Identification and enumeration of the phytoplankton were performed by inverted microscope equipped with 5 ml counting chamber. Totally 34 species of phytoplankton belonged to Green algae, Diatomes, Cyanobacteria and Euglenophyta were determined. Statistical analysis was carried out by PCA and UPGMA methods. The analysis of data by PCA showed that first and second axis created 99% of changes alone. There were 3 completely distinct groups of samples regarding the sampling seasons. The most effective physico- chemical factors influenced the phytoplankton communities were water transparency, EC and water temperature.

    Keywords: Shahrchai reservoir, Physico-Chemical factors, Phytoplankton
  • Bijan Mostafazadeh, Fereidun Mohebbi, Masoud Seidgar, Ali Nekuiefard Pages 104-110

    This study was conducted to investigate reproductive characteristics of four Artemia populations (A. urmiana, A. franciscana, Pakistan and Turkmenistan strains) cultured under the identical laboratory condition and fed on a unicellular alga. Cysts were hatched by standard methods and the nauplii from the populations were cultured in laboratory condition using 80 g/l salinity, 25±1ºC with photoperiod (12L: 12D). Dunalliella tertiolecta fed to all Artemia populations. To determine the reproductive characteristics, 30 pairs of adult Artemia of each population were randomly placed in 50ml conical falcons so that each conical falcon contains a pair of Artemia. The number of cysts and nauplii in each falcon were counted daily. All data were analysed using SPSS, one way ANOVA. The results showed that in all Artemia populations, the daily nauplii production were higher than cyst production. Also, during reproductive period, A. franciscana had the highest cyst production (639±105) and A. urmiana had the highest nauplii production (78.5±7). The highest and the lowest birth rate were related to A. franciscana (1225±193) and Turkmenistan strain (362±29), respectively. Therefore, it is suggested that A. urmiana and A. franciscana were perefered species for cysts production. Turkmenistan strain was not recommended for production plans, due to low cysts and nauplii production.

    Keywords: Artemia, Reproduction, Dunaliella tertiolecta, Geographical origin
  • Akram Ahmadi, Masoud Sheidai, Hossein Riahi Pages 112-116

    Chara is an interesting genus from cytological view has been extensively worked out in Europe and North America, but there is a few reports on Asian Charophytes. Chromosome number were determined for 10 species of Chara from 33 populations. Chromosome counts were as follows: C. connivens, n=14, C. contraria, n= 28; C. crassicaulis, n=21; Chara gymnophylla var. gymnophylla, n=14; Chara gymnophylla var. rohlenae, n=14; C. kirghisorum, n=14; C. kohrangiana, n=21, C. socotrensioides, n=14; C. tomentosa, n=14; Chara vulgaris var. longibracteata, n=28 and Chara vulgaris var. vulgaris, n=28. Authors made cytological studies of Iranian charophytes in twelve taxa which 10 taxa are new for Iran and five taxa are new for science.

    Keywords: Chromosome number, Chara, Charophytes, Iran
  • Zahra Mohammadzadeh, Reza AnsariTadi Pages 117-122

    Algae have been described as more than 1800 genera and 2100 species which are different in terms of the biology, size, structure, and physiology. In this study, the phytoplankton populations of 15 khordad dam reservoir in Qom Province were determined. Four sampling sites were selected for this study. Sampling was carried out from January 2014 to June 2015 to assess algal flora and frequency of phytoplanktons. The results showed that Phytoplankton assemblage comprised several taxa from Diatomaceae (41.1%), Dinoflagellaceae (32.5%), Chlorophyceae (23.2%) and Cyanophyceae (3.2%). Among identified taxa, Cyclotella from Diatomaceae, Peridinium from Dinoflagellaceae, Chlorella from Chlorophyceae and Oscillatoria from Cyanophyceae being the predominant genera in each phylum. The maximum and minimum frequencies were recorded at one meter depth in west side edge during June and at five meter depth in the east side edge of the reservoire during December, respectively.

    Keywords: Frequency, Algal flora, Phytoplankton, 15thKhordad dam