MOLECULAR STUDIES ON ALKALIPHILIC MICROORGANISMS IN TURKEY
Nilgun POYRAZ, Mehmet Burcin MUTLU
Anadolu University, Faculty of Science, Department of Biology, TR26470, Eskişehir, Türkiye Tel: +90
222 335 0580 / 4711, Fax: + 90 222 320 49 10
e-mail: nilgunpoyraz@anadolu.edu.tr
ABSTRACT
Van Lake has an area of 3,713 km2 which makes it the largest lake in Turkey. Van Lake
is located in the east of Anatolia-Turkey. It is situated at an altitude of 1649 meters. Van Lake
is considered to occur in the middle of Mus-Van Depression' in the Quaternary. It shows
alkaline feature. In this study water samples from Van Lake were collected from four different
locations. Samples’ pH, salinity and chemistry were analyzed. For determination of Van Lake
bacterial diversity, a combination of culture-dependent and independent techniques was
applied. 16 S rDNA based phylogenetic analyses were applied to study cultivable bacterial
diversity. 16S rRNA gene sequences were compared with reference sequences at NCBI using
BLAST. According to the BLAST results, Halomonas, Alkalimonas, Marinobacter, Vibrio,
Rhodococcus in Bacteria domain were identified as dominant species. Denaturing Gradient Gel
Electrophoresis (DGGE) and Fluorescence In Situ Hybridization (FISH) were used in this
study. Total nucleic acid extraction from all water samples was applied. Bacteria specific primer
combination was used and DGGE was performed using a denaturing gradient of 30% to 60%
denaturants in polyacrylamide gel. Selected 15 bands were excised from the gel, reamplified
and 10 of these bands were sequenced. For FISH analysis, 16S rRNA-targeted Bacteria specific
oligonucleotide probe EUB338 was used for hibridization and DAPI staining was applied. After
the fluourescence microscopy examination, the community was dominated by Bacteria and
presence of the long and short rods, curved rods, spiral-shaped cells, coccus-shaped cells and
spindle-shaped cells were detected in the samples.
Key words: Van Lake,16S rRNA, FISH, DGGE, Bacteria.