Investigation of viral diversity in Tuz Lake

Viruses exist high levels in the aquatic environments and it is believed that they are the main factors that affect the microbial biomass, population and genetic diversity and also long term evolution. Because of these roles, to determine the viral abundance becomes the main step of many studies.With this study the viral diversity in Tuz Lake was determined by using microscopy and molecular genetic based methods and examined with culture-independent approaches. Viral abundance was determined as 109 VLP/ml with using Epifluorescence Microscopy (EFM) after SYBR Gold staining of water sample. Pulsed-field Gel Electrophoresis (PFGE) was performed after filtration and concentration of water sample, and dominant bands were found nearly 30-40 kb in viral assemblage. By Transmission Electron Microscopy (TEM) virus particles were detected with different morphologies. Icosahedral viruses and spindle-shaped viruses were constitute high range of viral diversity whereas head and tail viruses were formed nearly 4% of viral diversity. The filamentous and rod-shaped viruses were seen in Tuz Lake, and also until today they only seen in Great Salt Lake (Utah) and solar saltern in Spain. Also, the bullet-shaped virus morphology determined the first time in Tuz Lake with this study and consists nearly 12% of viral diversity. Viral DNA was extracted and cloned in fosmid vectors to generate metagenomic library. This was the first time that viral diversity of Tuz Lake was propounded and characterized.Microbial diversity was also investigated, by Denaturing Gradient Gel Electrophoresis (DGGE) Haloquadratum and Salinibacter were found dominant in Archaea and Bacteria domains, in respectively. Fluorescence In-situ Hybridization (FISH) the community was detected dominant in Archaea domain.Key Words: Tuz Lake, Haloviruses, Culture-independent approaches.