Purification and characterization of two new cell-bound bioactive compounds produced by wild Lactococcus lactis strain

Abstract

Novel compounds and innovative methods are required considering that antibiotic resistance has reached a crisis point. In the study, two cell-bound antimicrobial compounds produced by Lactococcus lactis ID1.5 were isolated and partially characterized. Following purification by cationic exchange and a solid-phase C18 column, antimicrobial activity was recovered after three runs of RPC using 60% (v/v) and 100% (v/v) of 2-propanol for elution, suggesting that more than one antimicrobial compound were produced by L. lactis ID1.5, which were in this study called compounds AI and AII. The mass spectrum of AI and AII showed major intensity ions at m/z 1070.05 and 955.9 Da, respectively. The compound AI showed a spectrum of antimicrobial activity mainly against L. lactis species, while the organisms most sensitive to compound AII were Bacillus subtilis, Listeria innocua, Streptococcus pneumoniae and Pseudomonas aeruginosa. The antimicrobial activity of both compounds was suppressed by treatment with Tween 80. Nevertheless, both compounds showed high stability to heat and proteases treatments. The isolated compounds, AI and AII, showed distinct properties from other antimicrobial substances already reported as produced by L. lactis, and have a significant inhibitory effect against two clinically important respiratory pathogens.

Purification and partial characterization of antilisterial bacteriocin produced byPediococcus pentosaceusKJBC11 fromIdlibatter fermented withPiper betleleaves

“…The hydrophobic interaction chromatography performed on the re‐run gave good antilisterial activity in 10% isopropanol eluent in which the bacteriocin was found to be pure with a single peak having retention time of 15.86 min (Figure c). This strategy has been applied by many researchers to purify bacteriocins (Khochamit, Siripornadulsil, Sukon, & Siripornadulsil, ; Sahoo, Jena, Patel, & Seshadri, ; Saraiva et al, ; Sawa et al, ), however, other techniques such as fast protein liquid chromatography (FPLC) and filter assisted size exclusion protein fractionation were employed to speed up the purification of bacteriocins (Choi, Cheigh, Kim, & Pyun, ; Chumchalova, Stiles, Josephsen, & Plockova, ). The inhibitory activity, specific activity, and yield of bacteriocin KJBC11 obtained are presented in Table .…”

Purification and characterization of a broad spectrum bacteriocin produced by a selected Lactococcus lactis strain 63 isolated from Indian dairy products

“…lactis A164 (isolated from Kimchi) after ammonium sulphate precipitation and tenfold purification was achieved. Saraiva et al 2014 found 20% recovery and 10 fold increases in specific activity after ammonium sulphate precipitate. For the removal of salt the precipitate was dialyzed against distilled water and concentrated to original volume.…”