Biography
Derya Önal Darilmaz has completed her PhD from Gazi University. She is working as Associate Professor, Doctor in Aksaray University. Her areas of expertise are probiotics, food microbiology and microbial biotechnology. She has published more than 15 papers in reputed journals and serving as an Editorial Board Member and Referee in different reputed journals.\r\n\r\n\r\n
Abstract
Enterococci belong to the lactic acid bacteria (LAB) and they are of importance in foods due to their involvement in food spoilage and fermentations, as well as their utilization as probiotics in humans and slaughter animals. The purpose of this study was to evaluate the probiotic properties of Enterococcus faecium RI 41, RI 56, RT 81 strains isolated from traditional naturally fermented cheese produced in different regions of Iran and Turkey. The ability to autoaggregation and coaggregation are desirable properties for probiotics in health-promoting foods. Therefore, in the current study, we assessed the effect of exopolysaccharides (EPSs) produced by E. faecium strains on the aggregation and hydrophobicity properties. All E. faecium strains tested showed autoaggregation (38.80-53.50%) and coaggregation ability (18.55-35.25%) with Escherichia coli ATCC 11230, but the results were strain specific and dependent on exopolysaccharides production (129-185 mg/L). In addition, enterococci strains tested were showed affinity to all solvents (chloroform, p-xylene, toluene and ethyl-acetate), suggesting a high complexity of the cell surface. Our results indicate that the ability to autoaggregation, together with cell-surface hydrophobicity and coaggregation abilities with E. coli strain can be used for preliminary screening in order to identify potentially probiotic bacteria suitable for human or animal use.\r\n\r\n\r\n
Biography
Derya Önal Darilmaz has completed her PhD from Gazi University. She is working as Associate Professor, Doctor in Aksaray University. Her areas of expertise are probiotics, food microbiology and microbial biotechnology. She has published more than 15 papers in reputed journals and serving as an Editorial Board Member and Referee in different reputed journals.
Abstract
Hypercalciuria and hyperoxaluria are among the most important pathophysiologic causes of kidney stone formation. An increased intestinal absorption of oxalate is known to lead to hyperoxaluria with a significantly enhanced risk of urinary stone formation. In the present study, five strains of Propionibacterium were examined for their abilities to survive at 10 and 20 mM oxalate concentrations, and exopolysaccharide (EPS) production in these conditions as well as oxalate degrading activities. To determine the toxic effect of oxalate on EPS production ability and viability, EPS production of Propionibacterium strains was determined in yeast extract-lactate (YEL), 10 and 20 mM YEL-ox media. All strains grew in the presence of 10 and 20 mM sodium oxalates illustrating that oxalate at these concentrations are not toxic to Propionibacterium strains. No major loss of viability was observed at YEL-ox media. A high variability in the oxalate-degrading capacity was found in the different species and oxalate concentrations. The high EPS-producing P. jensenii BDP6 and P. freudenreichii subsp. freudenreichii DO8 strains showed high oxalate degrading activity, whereas the low EPS-producing P. jensenii DO6 showed low oxalate degrading activity in both oxalate concentrations. A better understanding of the mechanisms related to EPS production and oxalate degrading activity can be used for preliminary screening in order to determine potentially probiotic bacteria applications for human or animal use.