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Öğe Bifidogenic effect and in vitro immunomodulatory roles of melibiose-derived oligosaccharides produced by the acceptor reaction of glucansucrase E81(Elsevier Sci Ltd, 2020) Ispirli, Humeyra; Kaya, Yasemin; Dertli, EnesGlucansucrases are responsible for the production of alpha-glucans using sucrose as the substrate. Glucansucrases may also produce different oligosaccharides by transferring the glucose moiety from sucrose to a variety carbohydrates acting as acceptor nucleophile. In this study, melibiose-derived oligosaccharides were produced by the glucansucrase from Lactobacillus reuteri E81 expressed without the N-terminal region (GtfA-Delta N). The reaction products were characterized by TLC, LC-MS and NMR analysis and it was found that GtfA-Delta N synthesized melibiose-derived oligosaccharides (DP3 and DP4) by adding glucose units through alpha 1- > 3 or 1- > 6 glycosidic bond. The functional characteristics of these melibiose-derived oligosaccharides were determined by testing the immune-modulatory functions in HT-29 cells and testing their growth promoting effects for important probiotic and pathogenic strains. The melibiose-derived oligosaccharides triggered the production of anti-inflammatory cytokine IL-10 and pro-inflammatory cytokine TNF-alpha depending on their concentrations. Finally, melibiose-derived oligosaccharides showed bifidogenic effect as potential prebiotics.Öğe Comparison of the probiotic characteristics of Lactic Acid Bacteria (LAB) isolated from sourdough and infant feces(Elsevier, 2022) Kaya, Yasemin; Erten, Tayyibe; Vurmaz, Melike; Ispirli, Humeyra; Simsek, Omer; Dertli, EnesProbiotics are beneficial microorganisms with certain characteristics such as survival under gastrointestinal conditions, adhesion to intestinal surface and different functions which result in several health benefits to host. With this regards, this study aimed to isolate Lactic Acid Bacteria (LAB) from sourdough and human feces as two different environments and to test their potential probiotic functions. In total nine distinct isolates were assessed with several probiotic functions such as in vitro adhesion to human colon cells, antimicrobial activities and survival under harsh gastrointestinal conditions. In general, distinct strains showed strong antimicrobial activity against the pathogenic and fungal strains tested in this study. Importantly, the adhesion levels to HT29 cells were determined between 0.29 % and 9.54% and Lactobacillus paracasei F7B showed the highest adhesion. All isolates tolerated the bile salt after 24 h and the infant feces isolates showed good survival characteristics at pH 4.Öğe Farklı kaynaklardan izole edilen laktik asit bakterilerinin (LAB) probiyotik potansiyelinin belirlenmesi(Bayburt Üniversitesi, 2020) Kaya, Yasemin; Dertli, Enes; Erten, TayyibeProbiyotikler, gastrointestinal sistem şartlarında canlılığı kaybetmeden insan bağırsak mukozasına kolonize olan ve intestinal sistemde çeşitli fonksiyonlar icra ederek canlıların sağlığını olumlu yönde etkileyen mikroorganizmalardır. Şimdiye kadar farklı kaynaklardan probiyotik suşlar elde edilmiş ve bir kısmı çeşitli pazar paylarına ulaşmıştır. Yeni potansiyel probiyotik suşların izolasyonu da giderek önemi artan bir konu haline gelmiştir. Bu kapsamda bu tez çalışmasında ekşi hamur ve yeni doğmuş bebek dışkısından izole edilip tanımlanmış olan Laktik Asit Bakterisi (LAB) türlerinin probiyotik potansiyellerinin ortaya çıkartılması amaçlanmıştır. Bu doğrultuda test edilen suşlarda öncelikle EPS üretiminden sorumlu genlerin tespiti için PCR işlemi uygulanmıştır. Daha sonra üretilen EPS'in üretim seviyesi DNS metodu ile belirlenirken, EPS'lerin monosakkarit kompozisyonu ise HPLC analizi ile ortaya konmuş ve bütün suşların glukoz monomerinden oluştuğu tespit edilmiştir. Bu suşlarda antibiyotik dirençliliği test edilmiş, kanamycine karşı tüm suşlar direnç gösterirken, streptomycine karşı ise L.rhamnosus C-9A ve P.pentosaceus WPS-8 suşları dışındaki tüm suşlar direnç göstermiştir. Genellikle suşların çoğu, analiz edilen patojenlere karşı etki gösterirken, L. rhamnosus C-9A ve L. paracasei WPS-11 suşları ise Salmonella typhimurium'a karşı etki göstermemiştir. Ayrıca antifungal etki için 6 farklı küfe karşı etki araştırılmış ve test edilen türlerin önemli oranda antifungal aktivitesi olduğu ortaya konmuştur. Türler arasında belirgin farklılıklar olmakla birlikte n-hexadecene ile yapılan hidrofobiste tespitinde suşlar %3-81.2 oranında tutunma gösterdiği, en yüksek hidrofobikliği ise P.pentosaceus WPS-8 suşunun gösterdiği tespit edilmiştir. Ardından suşların insan HT-29 hücre hattına tutunma yetenekleri incelenmiştir. Tutunma oranlarının %0.29-9.54 arasında değiştiği ve L. paracasei C-7B suşunun en yüksek tutunum kapasitesine sahip olduğu görülmüştür. Genel olarak 24 saatlik inkübasyondan sonra tüm suşların iyi oranda safrayı tolere ettikleri tespit edilirken, pH 4'de ekşi hamurdan izole edilen suşların gelişimlerinde önemli oranda düşüş meydana geldiği tespit edilmiştir. Yine aynı şekilde simüle edilmiş gastrointestinal şartlarda suşların canlılıkları %39-97 arasında olduğu gözlemlenmiştir. Son olarak suşların GABA üretimi HPLC işlemi ile incelenmiştir. Sonuç olarak fermete ürünlerden ve bebek dışkısından izole edilen LAB türlerinden bazılarının potansiyel probiyotik olabilecekleri ortaya konmuştur.Öğe An integrated neural-fuzzy methodology for characterisation and modelling of exopolysaccharide (EPS) production levels of Leuconostoc mesenteroides DL1(Pergamon-Elsevier Science Ltd, 2020) Kabli, Mohammad; Yilmaz, Mustafa Tahsin; Taylan, Osman; Kaya, Yasemin; Ispirli, Humeyra; Basahel, Abdulrahman; Sagdic, OsmanOptimisation of exopolysaccharides (EPS) production in Lactic Acid Bacteria (LAB) is an important task as EPS production can be affected by different parameters. In this respect, this study aimed to characterise the structure of an EPS from Leuconstoc mesenteroides DL1 strain and to optimise the EPS production by determination of the effects of incubation time, sucrose concentration, incubation temperature and initial levan concentration (input parameters) using integrated ANNs (Artificial neural networks) and fuzzy modelling approaches. The characterisation of the EPS monomeric composition by HPLC analysis revealed that EPS DL1 was composed of glucose and fructose. The H-1 and C-13 NMR spectra of EPS DL1 also confirmed the glucan and fructan production. The effects of the input parameters on glucan and fructan production levels as output parameters by DL1 were optimised using neural network and fuzzy modelling tools. The fuzzy model was developed based on the recognition of basic elements of input-output parameters, and the power of ANNs used for system identification. A structural analysis was carried out to improve the flexibility of fuzzy model, and to design the unknown mappings of the input and output parameters more robustly. The parameters then were fine-tuned by qualitative reasoning to establish the relations of input output parameters using membership functions (MFs) and their intervals determination. A hybrid training algorithm was employed for parameter identification, MFs and their interval determination to obtain the fuzzy model. The model can predict the outcome parameters; glucan and fructan with high accuracy for the predetermined input parameters.Öğe Investigation of the relationship between NFKB1 polymorphisms and telomere length and apoptosis in patients with type-2 diabetes(Cukurova Univ, Fac Medicine, 2023) Dirican, Ebubekir; Kaya, YaseminPurpose: Type 2 diabetes mellitus (T2DM) is a heterogeneous, chronic, and metabolic disease that affects a significant proportion of the global population. This study aimed to evaluate the effect of NFKB1-94 ATTG ins/del polymorphisms on the expression of apoptosis genes and telomere length (TL) in patients with T2DM compared with healthy individuals.Materials and Methods: Sixty-nine T2DM patients and sixty healthy people were enrolled in the study. DNA and RNA were isolated from the blood samples. NFKB1 genotypes were identified by Sanger sequencing. For TL analyses and to investigate the expression of the caspase-3, caspase-9, bax, and bcl2 genes, RT-PCR was utilized.Results: There was a significant difference between the NFKB1-94 ins/del genotype patients and the control group (OR:0.4792 (0.2345-1.011)). However, the distribution of other genotype/alleles (ins/ins and del/del) showed no difference between T2DM and control groups. The allelic frequency of NFKB1-94 ins/del was 0.455/0.235 for the T2DM group and 0.435/0.165 for the control group. An increase in the mRNA expression of caspase-3, caspase-9 and Bax genes was observed in the T2DM group compared with the healthy group, while a decrease in the Bcl2 gene was found in the T2DM group. TL in T2DM patients was shorter than in healthy individuals.Conclusion: NFKB1-94 ins/del polymorphisms show significant differences in T2DM patients. We observed that apoptosis was activated and TL was shortened in patients with T2DM. However, no relationship between NFKB1 polymorphisms and apoptosis and TL could not be determined.Öğe Isolation and characterization of yogurt starter cultures from traditional yogurts and growth kinetics of selected cultures under lab-scale fermentation(Taylor & Francis Inc, 2023) Cakmakoglu, Selma Kayacan; Vurmaz, Melike; Bezirci, Emine; Kaya, Yasemin; Dikmen, Hilal; Goktas, Hamza; Demirbas, FatmanurThe development of new starter cultures is a crucial task for the food industry to meet technological requirements and traditional products are important reservoirs for new starter cultures. In this respect, this study aimed to isolate, identify, and determine the technological characteristics of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains originated from traditional yogurt samples. Genotypic discrimination of 200 isolates revealed the presence of distinct 19 S. thermophilus and 11 Lb. delbrueckii subsp. bulgaricus strains as potential starter cultures. Strain-specific properties determined the acidification capacity of the yogurt starter cultures and a higher acidification capacity was observed for S. thermophilus strains compared to Lb. delbrueckii subsp. bulgaricus strains. Proteolytic activity was found between 0.012-0.172 and 0.078-0.406 for S. thermophilus and Lb. delbrueckii subsp. bulgaricus strains, respectively. 4 of S. thermophilus and 3 of Lb. delbrueckii subsp. bulgaricus strains were found resistant to all tested bacteriophages. The antibiotic susceptibility tests of the isolates revealed that a very low antibiotic resistance was observed for the yogurt starter cultures. Finally, the growth kinetics of selected strains were determined and the maximum specific growth rate of selected S. thermophilus and Lb. delbrueckii subsp. bulgaricus was calculated as 0.527 h(-1) and 0.589 h(-1), respectively.
