modern research physics

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Oil pollutions as a consequence of increasing consumption of petroleum, have a tremendous effect on water and soil ecosystems and their microflora. In this study the diversity in physiological parameters, including growth rate, photosynthesis, chlorophyll-a and phycobiliproteins content, between cyanobacterial strains flora isolated from oil-polluted and non-polluted areas, were assessed. To this end, strains were isolated and purified. The experiments were carried out on logarithmic phase cultures of the isolates in suitable liquid media. The chlorophyll and phycobiliproteins contents were determined using a colorimetric method. Photosynthesis was measured by Oxyview apparatus. Growth rates were calculated based on dry weights. Under laboratory conditions, the photosynthesis activity and the chlorophyll content of isolates from oil-polluted sites were significantly lower than non-polluted isolates. On the other hand, the growth rate average of strains from oil-polluted sites was significantly higher than non-polluted strains. Also despite the higher phycobiliproteins content in non-polluted isolates, there was no significant difference in any of these pigments between the two groups. Altogether the results showed that in response to petroleum stress, the cyanobacteria restore the decrease in their chlorophyll content and photosynthesis activity by increasing their biomass. In fact the response is the reflects of restructuring cyanobacterial flora from sensitive autotrophic species to oil-pollution resistant mixotrophic species in the polluted ecosystems that in addition to photosynthesis are able to use crude oil as an energy source for their growth requirements, hence overcome the energy loss due to reduction of photosynthesis and even increase growth rate than non-oil-pollution isolates.

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The various species of Alveolina for biostratigraphy of Eocene sedimentary rocks are very important. In this research, the species of Alveolina  are reported for the first time in three cross sections: Chalonak, Kalaterood and East Beinabad. These sections are attributes to Early- Middle Eocene age. The 55 samples collected from Chalonak section and the thickness is reached to 245 m. In this section, four biozones are distinguished. They are following: Alveolina globula-Alveolina solida interval range zone, Alveolina solida-A .globosa interval range zone, Alveolina globusa total range  zone and  Alveolina aragonesis  total range zone. On the basis of index fossils such as  Alveolinana  avellana, A. aragonensis,A. globula, A. leupoldi, A. globusa, A. elliptica nutalli, A. rotundata, A. corbarica, A.solida, which are existing in these biozones, the age of this section is attributed to Early Eocene. Of course two species of Nummulites (Nummulites globulus, N. atacicus) and Cuvilierina valensis are determined in Chalonak section. The 80 samples are collected from Kalaterood section and the thickness is reached to 242 m. In this section, four biozones are distinguished. They are following: Alveolina solida- A. globosa interval range zone, Alveolina globosa total range zone, Alveolina aragonensis-A. canavarii interval range zone and A. canavarii total range zone. The several index fossils are found in this section following: Alveolina aragonensis, A. decipiens, A. Avellana, A. laxa, A. pasticillata, A. canavari, A . globosa and A. solida. The age of this section is Early Eocene.  The 150 samples are collected from East Binabad section and the thickness is reached to 900 m. In this section, four biozones are presented. They are Glomalveolina   lepidula – Alveolina solida interval rage zone. Alveolina elliptica nutali- Alveolina corbarica interval range zone, Alveolina corbarica total range zone and Alveolina ruetimeyeri-Alveolina levantina assemblage zone. There are several index fossils such as Alveolina corbarica, A. elliptica nuttalli, A.levantina,  A. roetimeyeri  and  A. decipiens, Glomalveolina lepidula. The age of this section is early Eocene.