Safety and Antioxidant Properties of Five Probiotic Lactobacillus plantarum Strains Isolated from the Digestive Tract of Honey Bees

Abstract

The objective of this study was the evaluation of safety, adhesion and antioxidant properties of five L. plantarum strains isolated from the digestive tract of honey bees. The set of variables generated from this study was submitted to a normalized Pearson (n) Principal Component Analysis (PCA). The five L. plantarum strains showed no gelatinase activity and were checked to be non-hemolytic. They were susceptible to chloramphenicol, amoxicillin, penicillin G and tetracycline. The MICs were ranged between 1-4 µg/ml for erythromycin and resistance was observed among 80% of strains (L. plantarum H15, H21, H24, and H28). A significantly high percentage of hydrophobicity in n-hexane was observed with L. plantarum H47 (71.99±1.39) followed by L. plantarum H28 (65.68±1.49) while the highest value in the presence of chloroform, belonging L. plantarum H24 and L. plantarum H28 (28.39±0.88 and 23.58±0.68 respectively). Both the Intact Cells (ICs) and Cell-Free Supernatants (CFSs) of L. plantarum H24 strain displayed the higher percentage (p 0.05) of DPPH radical scavenging activity (76.58±0.55% and 59.13±4.01% respectively). With the HRS activity, ICs of L. plantarum H24 strain exhibited the highest (p > 0.05) activity (73.37±0.62%) whereas, the CFS of L. plantarum H47 was the best (29.49±1.28%, p > 0.05). In all- purpose, based on PCA, L. plantarum H28, and L. plantarum H24 seem to be quite promising as they possessed the best properties tested. Accordingly, they can be chosen as representative of the potential probiotic strains.