Isolation, Biochemical Identification and Antioxidant Activity of Locally Isolated Lactobacillus spp in Garmian Area

The study was conducted in the Biology research laboratory In Garmian University during the period of summer to autumn 2016, which aimed to the isolation and biochemically identification of Lactobacillus sp. and comparing their antioxidant activity with Lactobacillus reuteri ATCC 23272, as well as both of the isolates and reference strain with ascorbic acid which used as a control. Out of 25 samples were collected from different sources such as vaginal swabs, infant stool, sheep and cow’s milk, six strains of Lactobacillus sp were Identified according to their colony morphology on MRS agar along with microscopic examination. Further identification strategies are carried out by biochemical analysis including catalase, oxidase, and API 50 CHL kit system through which strains as L. pentosus, L. acidophilus, L. collinoides, L. fermentum, L. salivarius and L. brevis were identified. The results of antioxidant activity which carried out by 2,2-DiPhenyl-2-Picryl hydrazyl hydrate ( DPPH) assay for all six isolated strains revealed that the best antioxidant activity was recorded by L. pentosus strain IC50=0.0464 which showed no-significantly differences with the ascorbic acid antioxidant activity IC50 = 0.0186, on the other hand, Lactobacillus reuteri ATCC 23272 exhibited antioxidant activity about IC50=1.998, in addition, other isolated strains L. acidophilus, L. fermentum, L. salivarius, L. collinoides and L. brevis demonstrates good antioxidant activity with IC50= 0.2311, 0.2792, 0.3707, 3.744 and 5.766 respectively.