Fermentation Technology

Acid, antibiotic resistance and inhibitory properties of Lactobacillus rhamnosus strains isolated from traditional Turkish cheeses

World Congress on Beneficial Microbes: Food, Pharma, Aqua & Beverages Industry

August 25-27, 2015 Valencia, Spain

Derya Onal Darilmaz, Kubra Dikbas Yildiz and Yavuz Beyatli

1University of Gazi, Turkey 2University of Aksaray, Turkey

Posters-Accepted Abstracts: Ferment Technol

Abstract:

In this study, a total of 12 Lactobacillus rhamnosus strains were isolated from traditional home-made Turkish cheese samples. The strains have been identified in species level by 16S rRNA gene sequence analysis. All strains were examined for their abilities to survive at pH 2.0, 3.0, 4.0, 5.06.5 and acid production, their influence on the growth of food-borne and spoilage bacteria as well as their sensitivity against 5 selected antibiotics. Acid tolerance of L. rhamnosus strains was highly variable depending on the strain and pH. L. rhamnosus BTM1 strain survived in all pH conditions. On average, all strains produced more acid in MRS medium. L. rhamnosus strains strongly inhibited growth of the Escherichia coli O:157H7 and Listeria monocytogenes ATCC 7644 strains. Most of the strains were affected by penicillin which inhibits the cellwall synthesis. The examined L. rhamnosus strains were resistant to polymyxin B, nitrofurantoin, gentamycin and ofloxacin antibiotics. These evaluations were performed as an initialstep toward establishing rational criteria for screening and selecting food-borne microorganisms with human probiotic properties.

Biography :

Derya Onal Darilmaz has completed her PhD from Gazi University. She is currently working as an 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.

Email: derya_onal@yahoo.com