Isolation and Characterization of an Anti-listerial Bacteriocin from Leuconostoc lactis SD501

Abstract

Although bacteriocins with anti-listerial activity have been isolated from a wide variety of lactic acid bacteria, little is known about those from Leuconostoc lactis, a heterofermentative bacterium that produces diacetyl and exopolysaccharides in dairy foods. In this study, an anti-listerial bacteriocin was isolated from Leuc. lactis SD501 and characterized. It was particularly potent against Listeria monocytogenes and also inhibited Enterococcus faecalis. Anti-listerial activity reached a maximum during the early stationary phase and then decreased gradually. The anti-listerial substance was sensitive to proteinase K and ɑ-chymotrypsin, confirming its proteinaceous nature. Its activity remained stable at pH values ranging from 1 to 10. In addition, it was strongly resistant to high temperatures, retaining its activity even after incubation for 15 min at 121℃. The apparent molecular mass of the partially purified anti-listerial bacteriocin was approximately 7 kDa. The characteristics of the SD501 bacteriocin, including its small molecular size (<10 kDa), strong anti-listerial activity, wide pH stability and good thermostability, indicate its classification as a Class IIa bacteriocin.

Bacteriocins: Properties and potential use as antimicrobials

“… 188 Several studies have identified bacteriocin‐producing strains of leuconostocs (Table 6 ). 189 , 190 , 191 Most Leuconostoc bacteriocins are classified as Class II, which are small (less than 10) and heat stable. They are non‐lanthionine‐containing bacteriocins without post‐translational modification.…”

Functional probiotics of lactic acid bacteria from Hu sheep milk

“…Studies have shown that the sensory characteristic properties of goat yogurt can be greatly improved by integrating the cultures of Leuconostoc lactis with traditional yogurt starters [11]. Moreover, Leuconostoc lactis is one of the most important species in the genus Leuconostoc, which plays an important role in the production of glucan and bacteriocin in the food industry [12,13].…”

Isolation and characterisation of the bacteriocin‐producingLeuconostoc citreumHW02from malts

“…citreum HW02 (Zangeneh et al ., 2020). Similar results showing the production of bacteriocin at the early exponential phase have been reported (Xiraphi et al ., 2008; Hwang et al ., 2018; Woo et al ., 2021). Maximal production of bacteriocin HW02 was detected at the middle of the stationary phase (at 12 h) as 320 AU mL −1 , and the pH was 4.51.…”

“…On the basis of the location of the inhibition zone, the crude bacteriocin molecular weight was determined to be approximately 7.4 kDa, which is similar to the finding reported in a study by Hwang et al . (2018). However, the determination of molecular weight using the crude bacteriocin cannot reveal the accurate molecular weight because a protein having a molecular weight similar to that of bacteriocin can be precipitated along with bacteriocin HW02 in the ammonium sulphate precipitation step.…”