Bahareh Nowruzi

Bahareh Nowruzi

Title: Title: The effect of environmental factors on extracellular polymeric substance production by soil cyanobacterium Nostoc

Bahareh Nowruzi

Islamic Azad University, Iran

Biography

Dr. Bahareh Nowruzi Plant Physiology (PhD), now is an Associate professor of Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran. She hold a masters degree in plant ecology from Shahid Beheshti University of Kerman, Iran. Her Master’s degree was awarded in 2005. After her master, she started a PhD project. She holds a PhD in plant physiology from Department of Biology, Kharazmi University, Iran (2008-2012) on a project looking at the genetic potential for production of secondary metabolites in Nostoc. She has experience with isolation and cultivation of microalgae, molecular taxonomy of microalgae and other molecular methods, and experience with analyses of bioactive compounds using LC-MS and HPLC. She was the first author on 5 published papers in international journals, co-author on one paper in press in journal of Natural Products, and first author on 5 papers in national journals. She has been attending 12 international scientific meetings with poster presentations in the years 2005-2012. Moreover, I spent 6 months as sabbatical leave at Helsinki University. Her supervisor was professor K. Sivonen, (Department of Applied Chemistry and Microbiology, University of Helsinki, P. O. Box 56, Viikki Biocenter, Viikinkaari 9,FIN-00014 Helsinki, Finland). She worked on bioactive compounds of cyanobacteria, isolation with with LC-MS and purification with HPLC. She obtained some experience on Molecular Biology (DNA or RNA extraction, PCR, PCR Sequencing, Cloning, Protein Expression and purification, N -15 labeling and Amino acid analysis).

Abstract

Cyanobacteria are an interesting group of photosynthetic prokaryotes with a great potential in drug discovery and scientific research. Cyanobacteria are able to produce extracellular polymeric substances (EPS) mainly of polysaccharidic nature in the outer membrane layer. Bound EPS serve as a boundary to the immediate environment and play a protective role against desiccation or as antimicrobial agents. This study aims to determine the influence of different laboratory growth conditions on the biomass and EPS production by one Nostoc strain, a diazothophic cyanobacterium. A study of some culture media was tested, with or without NaNO3 addition and mixotrophic growth conditions with two luminous intensities: 50 and 150 μ mol photon m–2 s–1. Cell growth and EPS production are both highly dependent on culture conditions, but there is no correlation between cell growth and EPS production in cultures grown in medium without NaNO3. mixotrophic growth conditions with high light intensity, was better than BG11 with NaNO3. Moreover, Results showed that stirring of culture media has very strong positive effect on maximal EPS concentration (3.01 g L-1). The massive release of this polysaccharidic material into the liquid medium made the cultures pro- gressively more viscous and The high viscosities of the polymers suggested that they might be suitable for industrial uses. This study highlights the importance of physiological and nutrimental factors in maximization of EPS production.