Partial Purification and Characterization of produced Bacteriocins by Two East-Azarbayjan Native Isolates of Lactobacillus plantarum

In this study, some characters of produced bacteriocins by two isolates of L.plantarum were studied. At fiest, two native isolates of L.plantarum BL1 and L.plantarum EL3 were selected from microbial collection of ABRII, and then the antibacterial trait and inhibitory spectrum of produced bacteriocins were determined. Therefore, bacteriocidal or bacteriostatic activity of produced bacteriocins, and thermal stability of them in different tempretures were studied. Molecular weight of bacteriocins were estimated by SDS-PAGE technique. According to achieved results, produced bacteriocins by two isolates were active against all used pathogens and had wide inhibitory spectrum, and even after different thermal treatments they retain their antibacterial activity. Also, it was observed that both produced bacteriocins were sensitive to proteinase-K and destroyed completely. In contrast, alpha-chymotrypsin was not able to destroy bacteriocins properly. On the other hand, it was revealed that L.plantarum BL1 bacteriocin had bacteriocidal effect on Eschrichia coli (ATCC 1399), but bacteriostatic activity against Yerssinia entrocolitica (ATCC 35669) as indicator pathogens. L.plantarum EL3 bacteriocin showed bacteriostatic activity on both noted indicator pathogens. Produced bacteriocins by both studied L.plantarum strains, had molecular weight lower than 10 kDa ( 5 kDa < produced bacteriocins < 10 kDa) and taked place in specified range of class IIb bacteriocins.