Metagenomic analysis of bacterial isolates obtained from different sources

Microorganisms are the most abundant biological entities on Earth and provide the greatest biological and genetic diversity. These many microorganisms play an important role in the energy and matter cycles that sustain all life. Until recently, this vast microbial world has mostly been explored by classical microbiological and culture-dependent methods. Recent advances in generating metagenomes, which are large examples of random nucleic acid sequences isolated directly from the environment, provide comprehensive portraits of the composition, structure, and functioning of microbial communities. The metagenomic study is an emerging field that identifies the total genetic materials in an organism and all genetic materials such as deoxyribonucleic acid and ribose nucleic acid that play key roles in maintaining cellular functions. The best part of this technology is that it gives environmental microbiologists more flexibility to instantly lead to the enormous genetic variability of microbial communities. In this thesis, metagenomic analysis of bacterial isolates obtained from different sources such as Küçükçekmece Lake, Manyas Lake and Western Black Sea Region was performed by Istanbul University Department of Biology, Department of Basic and Industrial Microbiology (TEMA) Laboratory. These isolates, which were phenotypically identified by standard biochemical methods using the commercially available API 20E test system by TEMA Laboratory, were genotypically amplified and sequenced with the 16S bacterial rRNA gene, polymerase chain reaction (PCR). The sequence of the PCR product was compared with known 16S rRNA gene sequences in the SILVA (Version 99) database by multiple sequence alignment. This study can be considered as an exemplary study showing the importance of metagenomic analysis, which is one of the more reliable, inexpensive and fast identification methods, and those phenotypic descriptions using classical methods can lead to errors.