Investigation of probiotic properties of Lactobacillus helveticus 2/20 isolated from rose blossom of Rosa damascena Mill.

¹ Department of Biochemistry and Molecular Biology, Technological Faculty, University of Food Technologies, 4002, Plovdiv, Bulgaria
² Department of Microbiology, Technological Faculty, University of Food Technologies, 4002, Plovdiv, Bulgaria
³ Department of Technology of Wine and Beer, Technological Faculty, University of Food Technologies, 4002, Plovdiv, Bulgaria

^* Corresponding author: rositsa_denkova@uft-plovdiv.bg

Abstract

A Lactobacillus strain was isolated from rose blossom of Rosa damascena Mill. and it was identified as belonging to the species Lactobacillus helveticus by the application of physiological-biochemical (API 50 CHL) and molecular-genetic methods (sequencing of the 16S rRNA gene). The presence of a number of probiotic properties of L. helveticus 2/20 was investigated. The strain exhibited high antimicrobial activity against pathogenic microorganisms that cause food toxicoinfections and intoxications. L. helveticus 2/20 survived in the simulated conditions of the gastrointestinal tract – pH = 2 and pepsin, pH = 4.5 and pancreatin and pH = 8 and pancreatin, as well as in the presence of up to 0.3% bile salts, retaining a significant concentration of viable cells. It has been shown that L. helveticus 2/20 cells begin multiplying after removing the extreme conditions. The strain allowed bioreactor cultivation and freeze-drying of the obtained concentrates, with the concentration of active cells in the lyophilic preparations exceeding 10¹² cfu/g. The kinetic parameters of the batch cultivation process in a bioreactor with stirring and the maximum growth rate were determined, revealing the possibilities for scaling up of the fermentation process from laboratory to industrial conditions, as well as its management. After further research on the probiotic properties of L. helveticus 2/20, it can be included in the composition of probiotics and functional foods.