Genome sequences of five Lactobacillus sp. isolates from traditional Turkish sourdough

A high level of variation in microflora can be observed in profiles of lactic acid bacteria (LAB) from sourdoughs. Here, we present draft genome sequences of Lactobacillus reuteri E81, L. reuteri LR5A, L. rhamnosus LR2, L. plantarum PFC-311, and the novel Lactobacillus sp. strain PFC-70, isolated from traditional Turkish backslopped wheat sourdoughs. © 2018 Dertli et al

Biochemistry and functional analysis of exopolysaccharide production in Lactobacillus johnsonii

Lactic Acid Bacteria (LAB) produce unique exopolysaccharides (EPS) that are important in food industry but they also play critical role in bacterial interactions during colonisation of the gastrointestinal tract. The role of this layer in the virulence of pathogenic bacteria has been well described but the biological importance of the EPS layer of probiotic bacteria have not been studied to the same extent. The aim of this thesis is to investigate the structure, biosynthesis mechanism and the biological role of the EPS produced by a probiotic strain of Lactobacillus johnsonii FI9785 that is able to competitively exclude Clostridium perfringens from gastrointestinal tract. L. johnsonii harbours an eps gene cluster and a spontaneous mutation in the phosphoregulatory system of this cluster resulted in a colony switch from a rough morphology to a smooth one; similarly deletion of the epsE gene, that encodes the putative priming glycosyltransferase of the EPS biosynthesis, caused a huge increase in aggregation of L. johnsonii, which were shown to be related with EPS production levels. Structural analysis of the purified EPS showed that L. johnsonii could produce two types of EPS: EPS-1 and EPS-2. EPS-1 is a branched dextran with the unusual feature that every backbone residue is substituted with a 2-linked glucose unit and EPS-2 is composed of four glucose and two galactose units with a novel structure. Several mutants were generated with deletion of individual genes in eps cluster or the entire cluster to study the EPS biosynthesis mechanism. The ΔepsE mutant produced only EPS-1 but not EPS-2 whilst the deletion of the putative transcriptional regulator, epsA, and the entire eps cluster resulted in an acapsular phenotypes. These alterations in the cell surface of EPS specific mutants were demonstrated by differences in binding of an anti-wild type L. johnsonii antibody. The loss of the EPS layer increased the adhesion and autoaggregation properties of L. johnsonii in vitro but EPS layer was found to be protective against several antimicrobials and environmental stress conditions. Additionally EPS layer was shown to be important on physicochemical properties and biofilm formation of L. johnsonii. Furthermore the in vivo persistence properties of acapsular mutant and wild type were assessed in a mouse model and no difference was detected in their persistence. Finally, several glycosyltransferases within the eps cluster were expressed, activity assays were performed and a potential glycosyltransferase was biochemically characterised

Reversible DNA codes from skew cyclic codes over a ring of order 256

We introduce skew cyclic codes over the finite ring $\R$, where $u^{2}=0,v^{2}=v,w^{2}=w,uv=vu,uw=wu,vw=wv$ and use them to construct reversible DNA codes. The 4-mers are matched with the elements of this ring. The reversibility problem for DNA 4-bases is solved and some examples are provided

On Linear Codes Over a Non-Chain Ring

In this paper, we study skew cyclic and quasi cyclic codes over the ring S = F2 +uF2 + vF2 where u2 = u, v2 = v, uv = vu = 0.We investigate the structural properties of them. Using a Gray map on S we obtain the MacWilliams identities for codes over S. The relationships between Symmetrized, Lee and Hamming weight enumerator are determined

Structural analysis of the α-D-glucan produced by the sourdough isolate Lactobacillus brevis E25

Cereal-associated Lactic Acid Bacteria (LAB) are well known for homopolymeric exopolysaccharide (EPS) production. Herein, the structure of an EPS isolated from sourdough isolate Lactobacillus brevis E25 was determined. A modified BHI medium was used for production of EPS-E25 in order to eliminate potential contaminants. Analysis of sugar monomers in EPS revealed that glucose was the only sugar present. Structural characterisation of EPS by NMR and methylation analysis revealed that E25 produced a highly branched α-glucan with (α1→ 3) and (α1→6) glycosidic linkages, and was similar in structure to a previously reported EPS from Lactobacillus reuteri 180. The 1H and 13C NMR data were contrasted with newly recorded data for known polysaccharides (alternan, commercial dextran) which also contain α-(1,3,6)Glc branch points. It was found in both E25 EPS and alternan that NMR parameters could be used to distinguish glucose residues that had the same substitution pattern but occupied different positions in the structure

Borsa İstanbul Sektör Endekslerinin Volatilite Modellemesi

DergiPark: 827011trakyaiibfPay piyasalarında yatırımcıların karar almalarını etkileyen önemli bir gösterge olan volatilite, akademik finans literatüründe geniş bir çalışma alanı oluşturmaktadır. Çalışmada, BİST Banka, BİST Hizmetler, BİST Sınai ve BİST Ticaret endekslerinin 2011 - 2014 yılları arasındaki günlük kapanış fiyatlarından elde edilen zaman serilerine Genelleştirilmiş ARCH ailesi modelleri (GARCH-EGARCH-TARCH) uygulanmıştır. Elde edilen sonuçlar doğrultusunda, çalışmada kullanılan her sektör endeksi için farklı ARMA(p,q) düzey- lerde ARCH etkisi mevcuttur ve en iyi sonuç veren model sektöre göre değişmektedir

Knowledge and experiences of families regarding amber necklaces

BackgroundAmber necklaces have been used frequently to reduce the complaints of babies during teething. In this study, the knowledge and experience of families regarding the use of amber necklaces investigated.MethodsThe structured questionnaire was applied face-to-face to parents with a 4-24 month old baby who applied to the paediatric outpatient clinic.ResultsOne hundred one families participating in the study reported that they used the amber necklace most frequently for restlessness (n = 72, 71.3%). Eighty- three% of families reported that the amber necklace was beneficial. It determined that 2% of the babies had suffocation and 2% had problems dispersing the grains.ConclusionAlthough the parents think that the use of amber necklaces is effective during the teething period, they are not aware of the risks. It is important for healthcare professionals to inform their families about teething and especially the risks of using amber necklaces

The Relationship Between Helicobacter Pylori Infection and Blood Group

INTRODUCTION: Our aim in this study is to investigate the relationship between Helicobacter Pylori (HP) and blood group and other risk factors. METHODS: 373 patients who underwent gastrointestinal system (GIS) endoscopy and gastric tissue biopsies were taken into the study between March-2017 and June-2018. Demographic data, risk factors, endoscopic appearance and histopathological data of all patients were documented. Patients were divided into two groups according to the presence of HP. Patients were divided into two groups as HP-positive and HP-negative according to the presence of HP. The groups were compared in terms of blood group and risk factors. RESULTS: 190 (50.9%) of the cases included in the study were women and the mean age of all patients was 45.1 +- 14.9 (range: 18-86) years. HP was positive in 53.8% of cases included in the study. HP positive patients were seen to be younger (p <0.05). In addition, while there was a significant relationship between HP positivity and working status, poor hand hygiene, smoking and alcohol use (p <0.05), no significant relationship was found with the blood group (p> 0.05). DISCUSSION AND CONCLUSION: As a result, in this study, soso-demographic factors such as age, working status, hand hygiene, smoking and alcohol use were found to be a risk factor for HP positivity, while no significant relationship was observed between ABO blood groups and HP