Kazan Meslek Yüksekokulu / Kazan Vocational School

Permanent URI for this collectionhttps://hdl.handle.net/11727/2077

Browse

Now showing 1 - 2 of 2

Analysis of Probiotic Bacteria Genomes: Comparison of CRISPR/Cas Systems and Spacer Acquisition Diversity
(2021) Ilikkan, Ozge Kahraman; 0000-0001-5843-6868; 35068602; Q-9641-2019
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) genes constitute an adaptive (acquired) defense system of bacteria and archaea. Here 72 probiotic bacteria genomes were investigated in terms of the presence of CRISPR/Cas systems and phage/plasmid invaders through spacer analysis. 49 CRISPR/Cas systems were detected within probiotic strains, namely,17 type II-A, 10 type I-C, 8 type I-E, 5 Type I-U (I-G), 4 type III-A, 2 type I-B, 1 type I-A, 1 type IV-B, and 1 type II-C. The predicted target of spacers was determined in 25 strains and consequently, three different spacer and target patterns were revealed. The diversity of CRISPR spacers provides insight and understanding to determine strain-specific invaders of probiotic bacteria as well as their relationships between strains. CRISPR systems were clarified in many studies for genomic characterization. However, recently, endogenous genome editing with CRISPR has provided an approach for various genome editing projects. Thus, in the future, producing strain-specific phage-resistant starter cultures or probiotics by endogenous genome editing methods according to phage/plasmid survey can be utilized for industrial and pharmaceutical applications. Therefore, this study intended a comprehensive investigation of CRISPR systems of probiotic bacteria.
Comparison of bacterial and fungal biodiversity of Turkish kefir grains with high-throughput metagenomic analysis
(2021) Ilikkan, Ozge Kahraman; Bagdat, Elif Seyma; 0000-0001-5843-6868; Q-9641-2019
Kefir is a health-promoting fermented drink having complex microbiota. This complex microbiota consists of bacteria and yeast association that is bound together with a polysaccharide called kefiran. To date, the complex microbiota of fermented foods was enlightened with culture-depended methods, however, recently, metagenomic studies have been started to use to reveal microbial diversity of fermented foods such as kefir. In this present study, we investigated the microbiome of two artisanal Turkish kefir grains (namely, A and G) by high throughput sequencing at the species level. Additionally, physicochemical analyses were carried out besides enumerations of lactobacilli, lactococci, total aerobic, and bifidobacteria in fermented milk kefirs. In these two kefir grains, different bacterial and fungal populations were revealed. In kefir grain A, Bifidobacterium longum was the dominant species while in kefir grain G, Lactobacillus kefiranofaciens was dominant. Concerning fungal diversity, in kefir grain A, Naumovozyma dairensis was the dominant yeast, while in kefir grain G, Zygosaccharomyces rouxii was dominant. High-throughput sequencing studies have revealed that kefir grains were typically dominated by lactobacilli. But, in this study, Bifidobacterium longum was found as a dominant bacterium in kefir for the first time.