فهرست مطالب

Progress in Biological Sciences - Volume:7 Issue:1, 2017
  • Volume:7 Issue:1, 2017
  • تاریخ انتشار: 1396/02/01
  • تعداد عناوین: 10
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  • Maryam Fanaei *, Giti Emtiazi Pages 1-9
    The identification, differentiation and classification of microorganisms have been subjects of research for many years. Recently, Fourier transform infrared (FTIR) spectroscopy techniques have gained attention in the characterization and classification of microorganisms based on biochemical profiles and cell structure characteristics. In the present study, the characterization and differentiation of pigmented photoreceptor-producing microorganisms using FTIR spectroscopy was carried out. For this purpose some microorganisms were isolated from different environments, of which three photoreceptor-producing bacteria were selected to limit the scope of the study to one phenotypic characteristic. Genomic relatedness among the isolated strains was investigated and it was shown that these strains had similarities to the Kushneria marisflavi, Halobacillus halophilus and Halobacillus faecis species. In addition, Halobacterium salinarum was investigated as a typical representative photoreceptor-producing archaeon. Spectra (500-4000 cm-1) of the intact cells and crude extracted pigments were recorded on an FTIR spectrometer and compared with each other. The similarities among the spectra were evaluated using hierarchical cluster analysis and compared with the phylogenic tree based on genomic study. Our results demonstrate that hierarchical clustering based on extracted pigments shows separation of strains more distinctly than those based on intact cells. The results of the present study suggest that FTIR analysis of bacterial pigments is an easy and economical technique comparable to other phylogenetic markers, for the differentiation and characterization of bacteria.
    Keywords: phylogenetic marker, Fourier transform infrared (FTIR) spectroscopy, pigment, microorganism, classification
  • Reza Karimi, Akbar Norastehnia *, Hossein Abbaspour, Sakineh Saeidi Sar, Akram Sadat Naeemi Pages 11-20
    The increase of copper oxide nanoparticle (CuO-NP) utilization in industry during recent years has resulted in their entry into aquatic ecosystems. In light of this fact, we have studied the toxicity of CuO-NPs at various concentrations on Chlorella vulgaris using an algal growth inhibition test (OECD201). Chlorella vulgaris was grown in positive Zander (Z-8 + N) media in a growth chamber. After reaching to the logarithmic growth phase, the algae were exposed to various concentrations of CuO-NPs at intervals of 24, 48 and 72 hours. Algal cell numbers were counted daily and the data were analyzed by Probit analysis. Some parameters such as: the effective concentration (EC10, EC50, EC90), no observed effect concentration (NOEC), specific growth rate (μ), doubling time (G) and percentage growth inhibition (I %) were calculated. The values of EC10 = 12.588, EC50 = 43.699, EC90 = 152.019 and NOEC = 4.3699 mg/L were obtained after 72 hours. The results showed significant differences between control and treatments at specified intervals of cell density and percentage of growth inhibition (P <0.05). In addition, chlorophyll and carotenoid content in treated cells were significantly lower compared to those in control samples; a decrease in the efficiency of photosynthesis is very probably a major mechanism in the reduced growth and viability of C. vulgaris exposed to CuO-NPs.
    Keywords: Toxicity of nanoparticles, Percent inhibition of growth, Specific growth rate, Photosynthetic pigments
  • Mojtaba Mohseni *, Hoda Ebrahimi Pages 21-30
    Ethanol is renewable and safe fuel and it is mainly produced based on microbial fermentation. The present study aims to isolate and identify ethanol producing Zymomonas spp. from natural environments with characterization, optimization and evaluation of their ethanol productivity. Samples were screened for ethanol producing bacteria on RM medium. Ethanol producing isolates were selected for characterization. In addition, bacterial growth and ethanol production conditions were optimized based on pH, temperature, agitation, time and initial glucose concentration. The morphological, physiological and molecular characterization was investigated for identification of the isolates. Of all the 10 ethanol producing isolates, two highest producers were selected for further studies. Both of them were motile and catalase positive but failed to hydrolyze gelatin and produce H2S. Among them, ZYM6 was exhibited highest ethanol yield 6.28 gL-1 with optimum pH 6 and growth temperature 30˚C. In addition, ZYM6 and ZYM10 were exhibited highest ethanol yield 15.00 gL-1 and 12.00 gL-1 with xylose and tryptophan, respectively. Thus the optimum condition for ethanol production was a medium composed of pH 6, growth temperature 30-35 ˚C for 24-48 hours and xylose and tryptophan as carbon and nitrogen sources. The results of morphological and physiological characteristics showed that ZYM6 and ZYM10 were belonging to Zymomonas. Moreover, 16S rRNA sequencing and phylogenetic analyses exhibited that ZYM6 and ZYM10 were similar to Zymomonas mobilis with 99% homology. These native Zymomonas spp. can produce ethanol with high yield. In addition, xylose is a feasible feedstock for ethanol fermentation with high efficiency using these isolates.
    Keywords: Bacteria, Biotechnology, Ethanol production, Phylogeny, Zymomonas
  • Nasim Kashef *, Zahra Sadat Seyyedi, Ahmad Reza Gohari Pages 31-38
    Background
    Biofilm formation by Pseudomonas aeruginosa is a serious concern in treatment of diseases and medical industries. Natural products that originate in plants can influence microbial biofilm formation. The effect of ethyl acetate, methanol and water- methanol extracts of Quercus brantii on biofilm formation and biofilm disruption of P. aeruginosa were investigated in this study.
    Methods
    The effect of Q. brantii extracts on biofilm formation ability of P. aeruginosa (ATCC 27853) and clinical isolates was tested using crystal violet (CV) staining assay. Minimum biofilm eradication concentration (MBEC) of the extracts against pre-formed biofilms alone and in combination with N-acetylcysteine (NAC) was also investigated.
    Results
    Ethyl acetate extract of Q. brantii was the most effective extract and inhibited P. aeruginosa biofilm formation over 70%. It was followed by water-methanol extract (52% - 66% inhibition) and methanol extract (44% - 57% inhibition). Water-methanol extract of Q. brantii was more effective in eradication of P. aeruginosa pre-formed biofilms. The MBEC of Q. brantti extracts in combination with NAC was decreased in comparison to MBEC of Q. brantti extracts alone.
    Conclusion
    This study demonstrated that Q. brantii extracts had a good inhibitory effect on biofilm formation ability of P. aeruginosa and could eradicate preformed-biofilms in combination with NAC.
    Keywords: Bacteria, Biofilm formation, Biofilm eradication, Plant extract, Pseudomonas aeruginosa
  • Mohammad Reza Gharaati *, Sara Taleahmad, Siamak Rezaeiani, Mostafa Naghavi, Lida Habibi Rezaei, Ali Sayadmanesh Pages 39-45
    Insulin-like growth factor 1 (IGF-1) is a polypeptide hormone produced mainly by the liver in response to the endocrine growth hormone (GH) stimulus. This protein is involved in a wide range of cellular functions, including cellular differentiation, transformation, apoptosis suppression, migration and cell-cycle progression and other metabolic processes. In the current study, human heart cDNA was employed to isolate IGF-1 encoding fragment using reverse transcriptase (RT) PCR. The isolated fragment was cloned into pET32a expression vector and then transformed into the competent Escherichia coli Origami 2. After selecting the correct colony with the highest expression level, the colony was cultured and induced with IPTG. Recombinant IGF-1 expression was detected by SDS-PAGE and His-tagged protein purification was performed with the affinity chromatography. In order to confirm the activity of the resultant protein, biological activity of the recombinant IGF-1 was assayed through inducing proliferation of MCF-7 cells. Molecular techniques, including PCR, restriction digestion, mass spectrometry analyses, SDS-PAGE and biological activity analyses of this protein confirmed the correct cloning, expression, and function of IGF-1 in this study. Overall, we provided a rapid and cost effective production and purification method for IGF-1 protein, which is biologically active and functional.
    Keywords: Insulin like Growth Factor 1, Recombinant protein, Over expression, E. coli
  • Faezeh Khatami, farzaneh najafi *, Fataneh Yari, Ramazan Ali Khavari, Nejad Pages 47-52
    Magnetic nanoparticles separation technology is a method for quick and easy extraction biomolecules such as proteins, DNA and RNA. The present work describes total RNA isolation procedure from transformed rose petals in our laboratory using magnetic nanoparticles as a solid phase absorbant. Petals are the main sources of secondary metabolites, i.e. carotenoids, anthocyanins, flavonoids and phenolic compounds, which interfere with nucleic acids isolation. The physical basis of this technique relies on the interaction with external magnetic fields, and therefore the magnetic moment of the particles and nucleic acid plays the main role. The present work showed that, quantity and quality of extracted RNA by magnetic procedure were higher than that of the conventional method in all tested samples. Additionally, preparing RNA samples, take less than 50 minutes as against several hours taken by common protocols. Furthermore, successful RNA isolation was found to follow-up reactions such as PCR amplification and restriction endonuclease digestion especially in colorful petals. The solid-phase extraction method for the isolation of RNA in this research offers several advantages over the conventional methods using phenol-chloroform extraction: it is convenient to use, rapid, time-saving and reducing the consumption of toxic organic solvents; therefore, making it more amenable to automation.
    Keywords: Magnetic nanoparticles, PCR, RNA extraction, Transformed Rose petal
  • Shahin Zarre *, Nafiseh Yusefi, Guenther Heubl Pages 53-65
    Linaria Mill. (Plantaginaceae) with about 160 spp. is the largest genus of the tribe Antirrhineae. We conducted phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer region (ITS) and chloroplast DNA (rpl32-trnL) sequence data to test the monophyly of currently recognized sections in Linaria. For this purpose 86 species representing seven sections of Linaria and one species of Nuttallanthus along with representatives of four outgroup taxa of tribe Antirrhineae were analyzed. Phylogenetic analyses using Maximum Parsimony and Bayesian Inference reveal Linaria-Nuttallanthus as a monophyletic group composed of seven supported major clades that match partly with the current subgeneric treatment of the genus. Following sections are recognized here: Macrocentrum, Lectoplectron, Pelisserianae, Versicolores, Supinae, Diffusae, and Linaria. Based on our results sect. Linaria is expanded to include sect. Speciosae and some members of sect. Diffusae. A diagnostic key to sections and subsections of Linaria according this revised classification is presented. Our results indicate that seed features provide some synapomorphies for the main clades of Linaria, but their importance should be cautiously evaluated. In the case of winged and discoid seeds versus oblongoid ones, although the former seems to be the advanced state, it has been evolved independently in several sections/clades, i.e. Pelisserianae, Supinae, and Linaria. We propose major changes in circumscription of sect. Linaria which now embraces also some representatives with oblongoid seeds formerly assigned to sects. Diffusae and Speciosae.
    Keywords: Taxonomy, Seed morphology, nrITS sequences, rpl32-trnL marker, monophyly
  • Maryam Rezayian *, vahid niknam, Mohammad Ali Faramarzi Pages 67-77
    In this study, some physiological and biochemical responses of Synechococcus elongatus to salt stress were investigated. The cyanobactrium was grown in BG-11 medium under different concentrations of NaCl (0, 0.5, 1 M). The results indicated that the growth of S. elongatus was significantly inhibited under salt stress on days 5, 9 and 12. Protein content increased in S. elongatus on day 12 in presence of salt. Salinity induced proline accumulation at 1 M NaCl on day 12 and caused a significant enhance in hydrogen peroxide content on day 5. Catalase (CAT) activity continuously increased on day 5. An increasing trend in polyphenol oxidase (PPO) activity was indicated on days 5 and 9. Superoxide dismutase (SOD) activity gradually induced with increasing NaCl concentrations on day 5. Salt stress decreased chlorophyll content compared to that of control in three stages of growth, and carotenoid content declined on days 9 and 12. The contents of phycobiliprotein (PBP), phycoerythrin (PE) and phycocyanin (PC) enhanced significantly under different NaCl concentrations on days 5 and 9. These results show that S. elongatus has limited adaptative potential to salinity, and the optimum medium for its culture should not bear NaCl even at a moderate level, if production of carotenoids is aimed.
    Keywords: Antioxidant enzymes, Carotenoids, Phycobiliprotein, Cyanobacterial culture, Adaptation, Salt stress
  • Protective role of vitamin C on spatial memory and oxidative stress alteration during paraquat-induced toxicity in male rats
    Hassan Saei, Homeira Hatami *, Omid Purbagheriyan, Seyed Mohammad Hosseini, Gholamreza Dehghan Pages 79-85
    Paraquat (PQ), is one of the most widely used herbicides all over the world. PQ could induce dopaminergic cell death. Since dopamine involves in memory processing, we investigated the recovery effect of vitamin C on spatial memory along with oxidative stress parameters during PQ induced neurotoxicity in male rats. Rats were divided into five groups (n= 7): control (saline 0.9%), PQ (2.67 and 5 mg/kg), vitamin C (80 mg/kg) plus PQ (2.67), and vitamin C plus PQ (5 mg/kg). The period of intraperitoneal injection (i.p.) was once a day and for 5 consecutive days. The Morris water maze test used for studying the spatial memory. The level of lipid peroxidation (MDA), and activity of antioxidant enzymes; superoxide dismutase (SOD) and catalase (CAT), were determined in the left hemisphere of rats. Results showed that i.p. injection of PQ in both doses, 2.67 mg/kg (P<0.05) and 5mg/kg (P<0.01) significantly decreased the spatial memory. The total SOD activity in PQ-treated groups (2.67 and 5mg/kg) was significantly lower than that of control group (p<0.01). The level of CAT increased, in Vitamin C plus PQ groups in a dose-dependently manner (p<0.05). MDA was significantly increased in PQ-treated group (p<0.01). In PQ-treated groups that were supplemented with vitamin C, SOD activity and lipid peroxidation level were restored to normalcy. Our data revealed that PQ could impair the spatial memory via induction of oxidative stress in the brain tissue. Vitamin C can prevent or diminish the oxidative stress markers in the PQ-treated rats.
    Keywords: Antioxidant enzymes, Neurotoxicity, Oxidative stress, Spatial memory
  • Mitra Moezipour, Marjan Seiedy *, Jamasb Nozari, Ricardo Malheiro Pages 87-95
    Olive fly is the most dangerous pest in olive groves worldwide. Therefore the study of the most susceptible and resistant cultivars to olive fly can bring new information to diminish the olive flies harmful impacts. The main goal of the present study is to verify the olfactory response of olive fly to olive volatiles from five native Iranian cultivars (Fishomi, Mari, Rowghani, Shengeh, and Zard) and four exotic cultivars (Arbequina, Coratina, Koroneiki, and Manzanilla). Olfactometer bioassays were carried out in order to verify the attraction level of the volatiles of different cultivars to olive flies. A second experiment was performed with native cultivars in order to verify the preference between healthy olives and olives already infested by olive fly. The obtained results demonstrated that among native cultivars, Fishomi and Zard were those attracting higher number of olive flies, while cv. Rowghani showed to be the less preferred one. The exotic olive cultivars, Arbequina and Manzanilla attracted higher number of olive flies, while the volatiles of cv. Koroneiki showed a low attraction effect. According to the results of this study we suggest setting new strategies in cultivation of olives by spreading those cultivars less attractive to olive fly
    Keywords: Olea europaea, olive fruit fly, Cultivar preference, Olfactory response, Volatile compounds