Effects of concentrated supernatants recovered fromLactobacillus plantarumonEscherichia coligrowth and on the viability of a human promyelocytic cell line

Abstract

Aims: The ability of concentrated supernatants from Lactobacillus plantarum to produce a disruption of plasma membrane in eukaryotic and prokaryotic cells has been examined. Methods and Results: A strain of Lact. plantarum (tolerant to acid and bile salts and resistant to several antibiotics) was used. It inhibited the growth of pathogenic Escherichia coli and L. monocytogenes. Supernatants from Lact. plantarum were concentrated by centrifugation. Either E. coli or HL‐60 cells (a human promyelocytic cell line) were treated in the presence of the concentrated supernatants. The effect of concentrated supernatants from Lact. plantarum on E. coli growth demonstrated a bacteriostatic activity and a loss of cell viability measured by sytox green staining. Concentrated supernatants were capable of disturbing plasma membrane in E. coli and of promoting a cytotoxic and lyctic action on HL‐60 cells and on human erythrocytes, respectively. Conclusions: These results suggest that Lact. plantarum release an effective compound responsible for an important effect in the disruption of E. coli plasma membrane and for a cytototoxic activity on promyelocytic leukaemia cells. Significance and Impact of the Study: This is the first in vitro study about the antimicrobial and biological activities of concentrated supernatants from Lact. plantarum.

Analysis of Health Benefits Conferred by Lactobacillus Species from Kefir

“…This strain was further tested in a later study by these authors [27]. They confirmed the previous observation that the strain inhibited the growth of both L. monocytogenes and E. coli , as seen via a spot assay test.…”

Beneficial Effects of Tomato Juice Fermented by Lactobacillus Plantarum and Lactobacillus Casei: Antioxidation, Antimicrobial Effect, and Volatile Profiles

“…This activity might be due to some unknown characteristics of the outer membrane of L. casei [ 19 ]. Moreover, L. plantarum released an effective compound responsible for the important effect of disrupting the E. coli plasma membrane [ 20 ]. Other studies have also illustrated that three strains of L. plantarum from Balkan cheeses (CLP1, CLP2, and CLP3) exhibit high antibacterial activities that can be harnessed to control pediatric diarrhea, which is caused by the pathogenic strains of E. coli [ 21 ].…”

A Lactobacillus plantarum strain isolated from kefir protects against intestinal infection with Yersinia enterocolitica O9 and modulates immunity in mice

“…Moreover, pretreatment of mice with this strain drastically reduced proinflammatory cytokine levels in blood after challenge with Listeria monocytogenes, although survival was not improved [18]. In vitro, concentrated supernatants from L. plantarum C4 cultures exerted antibacterial and antitumor activities [19]. In batch cultures with fecal slurries and fructo-oligosaccharides, L. plantarum C4 stimulated growth of intestinal lactic acid bacteria, which was not seen with fructo-oligosaccharides alone [20].…”