Usage of ectoine as a cryoprotectant for cryopreservation of lactic acid bacteria.

Streptococcus thermophilus, the only Streptococcus species considered "Generally Recognized Safe", has been used widely in the food industry. This bacterium is one of the most valuable industrial lactic acid bacterial species. Due to the importance of this bacterium in industrial applications, it should be stored for a long time without losing its metabolic properties. The present study aimed to investigate the cryoprotectant effect of three compatible solutes (ectoine, trehalose, and sucrose) on bacterial cells stored at different temperatures (frozen at -80 °C or freeze-dried and subsequently stored at +4, -20, and -80 °C) for three months. The bacterial cells were tested for cell viability, bile salt tolerance, and lactic acid production before and after processing. The highest cell viability, bile salt tolerance, and lactic acid production were obtained with ectoine and under frozen (storage at -80 °C) conditions. In freeze-dried and subsequently stored at various temperatures, the best preservation was obtained at -80 °C, followed by -20 °C and +4 °C. Moreover, when ectoine's preservation potential was compared to other cryoprotectants, ectoine showed the highest preservation, followed by trehalose and sucrose. Although ectoine has a variety of qualities that have been proven, in the current work, we have shown for the first time that ectoine has cryoprotectant potential in yogurt starter cultures (S. thermophilus).

Carbonate and silicate dissolving bacteria isolated from home-made yogurt samples.

In the current study, twenty-eight bacterial strains were isolated from home-made yogurt samples from Agri Province, Turkey. The bacterial strains were identified by conventional and molecular techniques. Among the twenty- eight isolates, seventeen isolates were identified according to the 16 S rDNA region and determined to belong to five different genus including Sphingomonas (8 isolates), Burkholderia (5 isolates), Lactobacillus (2 isolates), Lactococcus (1 isolate), Staphylococcus (1 isolate). In this study, the presence of Burkholderia in home-made yogurt samples were reported for the first time, whereas Sphingomonas was detected for the second time. We also investigated the carbonate (CaCO3 and MgCO3) and silicate ( CaSiO3 and MgSiO3) dissolving potential of seventeen bacterial isolates. Among these seventeen bacterial isolates, fifteen bacterial isolates have CaCO3-dissolving and 10 bacterial isolates have MgCO3-dissolving potential. The silicates dissolution ability was relatively less than that of carbonates dissolving. We observed that six bacterial isolates have CaSiO3 and only two bacterial isolates have MgSiO3 dissolution abilities. In conclusion, this work clearly shows the diversity of bacteria existing in fermented cow milk samples in Agri Province, Turkey, which could be considered as valuable sources for lactic acid bacteria (LAB) isolation and further probiotic potential.

The Role of Calender Gap in Barrel and Screw Wear in Counterrotating Twin Screw Extruders.

It has been known in the industrial sector that in closely intermeshing counterrotating twin screw extruders, large separating forces develop in the calender gap, which push the screws towards the barrel wall. The result is significant wear in the region defined by 30°- and 60°-degree angles from the vertical. In the present investigation, pressures were measured around the barrel in extrusion of two rigid PVC resins in a laboratory extruder of 55 mm diameter and the forces on the screw core were determined. Numerical flow simulations were also carried out using the power-law viscosity parameters of the resins. From the experimental results, it was determined that the resultant forces are in the 30 degree angle direction, and from the computer simulations, the angle is between 18° and 25°. It is argued that the resultant force angle will be somewhat larger in large diameter extruders, due to the additional contribution of gravity.

Causes of erectile dysfunction in non-alcoholic fatty liver disease.

Background and Aim: Erectile dysfunction (ED) is an important and commonly seen disorder in patients with non-alcoholic fatty liver disease (NAFLD). The objective of this study was to assess the rate of ED and its causes in a group of NAFLD patients. Materials and Methods: The International Index of Erectile Function questionnaire (IIEF-5) was used to evaluate the presence, causes, and severity of ED. Participants with an IIEF-5 score of <22 who agreed to undergo a urological evaluation were referred to a urologist for further assessment. Results: A total of 136 NAFLD patients were enrolled in the study. According to the IIEF-5, 68 (50.0%) patients had ED. Multivariate analysis indicated that older age, obesity, and hypertension were associated with ED. Seventeen patients had multiple etiological factors for ED. Psychogenic ED was identified in 19 patients (39.6%), vasculogenic ED in 35 patients (72.9%), drug-related ED in 3 patients (6.3%), and neurogenic ED in 6 patients (12.5%). Conclusion: ED is frequently seen in NAFLD patients, which may, at least in part, be due to common risk factors. Vasculogenic dysfunction is the most common single source of ED in NAFLD patients. Nonetheless, all potential etiologies should be carefully investigated, with special attention given to psychogenic factors, since they may be more frequent and relevant than expected.

Evaluation of the Association between Programmed Cell Death-1 Gene Polymorphisms and Hepatocellular Carcinoma Susceptibility in Turkish Subjects. A Pilot Study.

BACKGROUND AND AIMS: Programmed cell death-1 (PD-1) has a vital role in regulating T-cell function, and immune escape mechanism of cancer cells. It was shown that there could be a relationship between single nucleotide polymorphisms (SNPs) in the PD-1 gene and susceptibility to hepatocellular carcinoma (HCC) based on various studies. We aimed to investigate the role of three SNPs within the PD-1 gene in susceptibility to HCC in the Turkish population. METHODS: Single nucleotide polymorphisms of PD-1.1, 1.5, and 1.6 were genotyped by using TaqMan Allelic Discrimination Assays in blood samples of 137 HCC and 136 control subjects, matched for age and gender. The genotype, allele and haplotype frequencies were compared in HCC and control groups using logistic regression analysis. RESULTS: Genotype distributions of PD-1.1, PD-1.5 and PD-1.6 SNPs were in Hardy-Weinberg equilibrium. No significant difference was observed in the genotype distribution of PD-1.1, PD-1.5 and PD-1.6 polymorphisms among gender and age-matched HCC (M/F: 96/41; mean age: 61.4 ±11.7 years) and control group (M/F: 94/42; mean age: 61.4±10.1). In the haplotype analysis of PD-1.1/PD-1.5/PD-1.6, no significant difference was found among HCC and control group adjusted for sex and age (all p values>0.1). CONCLUSION: Our findings, firstly reporting the association of PD-1.5 polymorphism with HCC, and PD-1.1 and PD-1.6 with HCC in the Turkish population, suggest that PD-1 polymorphisms are not predisposing factors for HCC development. Future studies with larger sample sizes and different ethnic populations are required to validate our findings.