Partial purification and characterization of bacteriocin produced byEnterococcus faecalisDU10 and its probiotic attributes

Abstract

A novel bacteriocin produced by avian duck isolated lactic acid bacterium Enterococcus faecalis DU10 was isolated. This bacteriocin showed a broad spectrum of antibacterial activity against important food-borne pathogens and was purified by size exclusion chromatography followed by reverse-phase high-performance liquid chromatography in a C-18 column. Tricine-SDS PAGE revealed the presence of a band with an estimated molecular mass of 6.3 kDa. The zymogram clearly linked the antimicrobial activity with this band. This result was further confirmed by mass-assisted laser desorption ionization time-of-flight mass spectrometry, since a sharp peak corresponding to 6.313 kDa was detected and the functional groups were revealed by Fourier transform infrared spectroscopy. Bacteriocin DU10 activity was found sensitive to proteinase-K and pepsin and partially affected by trypsin and α-chymotrypsin. The activity of bacteriocin DU10 was partially resistant to heat treatments ranging from 30 to 90°C for 30 min. It also withstood a treatment at 121°C for 10 min. Cytotoxicity of bacteriocin DU10 by methyl-thiazolyl-diphenyl-tetrazolium bromide assay showed that the viability of HT-29 and HeLa cells decreased 60 ± 0.7% and 43 ± 4.8%, respectively, in the presence of 3,200 AU/mL of bacteriocin. The strain withstood 0.3% w/v of bile oxgall and pH 2 affected the bacterial growth between 2 and 4 hr of incubation. Adhesion properties examined with HT-29 cell line showed 69.85% initial population of strain E. faecalis DU10, which was found to be strongly adhered to this cell line. These results conclude bacteriocin DU10 may be used as a potential biopreservative and E. faecalis DU10 may be used as a potential probiont to control Salmonella infections.

Probiotic characterization of bacterial strains from fermented South Indian tomato pickle and country chicken intestine having antioxidative and antiproliferative activities

“…A research has been carried out where the bacteriocin from Weissella hellenica D1501, isolated from Chinese traditional Dong fermented meat has also shown similar kind of phenomenon (Chen et al 2014). In another study, the crude and partially purified bacteriocins from E. faecalis DU10 and CV 7 isolated from duck and chicken intestinal homogenate has shown similar kind of results as compared to our studies (Perumal et al 2016;Perumal and Venkatesan 2017).…”

“…In another study, the crude and partially purified bacteriocins from E. faecalis DU10 and CV 7 isolated from duck and chicken intestinal homogenate has shown similar kind of results as compared to our studies (Perumal et al . 2016; Perumal and Venkatesan 2017).…”

Purification and Characterization of a Bacteriocin, BacBS2, Produced by Bacillus velezensis BS2 Isolated from Meongge Jeotgal

“…The absorption peak at 2,986 results in C-H stretching and designates the existence of an aliphatic chain. The peak at 1,460 and 1,401 cm -1 arises from the amide II bond which results from the deformation of N-H bond combined with C-N stretching molecule [27]. The peaks at 1,630 and 1,552 cm -1 indicate the existence of amide I and amide II.…”