Biotechnical paving of recombinant enterocin A as the candidate of anti-Listeriaagent

Abstract

BackgroundEnterocin A is a classic IIa bacteriocin isolated firstly from Enterococcus faecium CTC492 with selective antimicrobial activity against Listeria strains. However, the application of enterocin A as an anti-Listeria agent has been limited due to its very low native yield. The present work describes high production of enterocin A through codon optimization strategy and its character study.ResultsThe gene sequence of enterocin A was optimized based on preferential codon usage in Pichia pastoris to increase its expression efficiency. The highest anti-Listeria activity reached 51,200 AU/ml from 180 mg/l of total protein after 24 h of induction in a 5-L fermenter. Recombinant enterocin A (rEntA), purified by gel filtration chromatography, showed very strong activity against Listeria ivanovii ATCC 19119 with a low MIC of 20 ng/ml. In addition, the rEntA killed over 99% of tested L. ivanovii ATCC19119 within 4 h when exposed to 4 × MIC (80 ng/ml). Moreover, it showed high stability under a wide pH range (2–10) and maintained full activity after 1 h of treatment at 80°C within a pH range of 2–8. Its antimicrobial activity was enhanced at 25 and 50 mM NaCl, while 100–400 mM NaCl had little effect on the bactericidal ability of rEntA.ConclusionThe EntA was successfully expressed in P. pastoris, and this feasible system could pave the pre-industrial technological path of rEntA as a competent candidate as an anti-Listeria agent. Furthermore, it showed high stability under wide ranges of conditions, which could be potential as the new candidate of anti-Listeria agent.

Bacteriostatic activity and partial characterization of the bacteriocin produced by L. plantarum sp. isolated from traditional sourdough

“…To determine the bacteriocin thermostability, solutions containing the bacteriocin were firstly treated at 60°C, 80°C, and 100°C for 15 and 30 min, and 121°C for 15 min. Then, the samples’ antimicrobial activity was measured through the microtiter plate assay (Hu et al., 2014).…”

“…for 15 and 30 min, and 121°C for 15 min. Then, the samples' antimicrobial activity was measured through the microtiter plate assay (Hu et al, 2014).…”

Antimicrobial compounds produced by Enterococcus spp. isolates from fecal samples of wild South American fur seals

“…Mundticin KS showed an antimicrobial activity of 6,400 to 12,800 AU/mL-1 when produced in a fermenter (Kawamoto et al, 2002). Xiaoyuan et al (2014) showed the highest antilisteria activity reaching 51,200 AU/mL-1 from enterocin A after 24 h of induction in a 5 L fermenter. The ACs-J5 were stable within a wide range of pH and heat treatment and sensitive to all proteolytic enzymes tested, suggesting their proteinaceous nature.…”

Enterocin A mutants identified by saturation mutagenesis enhance potency towards vancomycin‐resistant Enterococci

“…Antimicrobial peptides (AMPs) are natural products that show promise in antibacterial applications for both the health care and food industries (Drider et al, ; Grosu‐Tudor et al, ; Hu et al, ; Kjos et al, ; Snyder and Worobo, ; Zhao et al, ). AMPs are typically cationic, amphiphilic peptides that serve as defense proteins for the producing organism (Drider et al, ; Fimland et al, ; Hwang and Vogel, ).…”

“…Bacteriocins are a specific group of AMPs that are produced by bacteria and, when created by LAB, are typically heat‐stable (Drider et al, ; Tagg et al, ). Bacteriocins have been studied for their potential in antibacterial applications both in the health care and food industries (Drider et al, ; Grosu‐Tudor et al, ; Hu et al, ; Kjos et al, ; Snyder and Worobo, ; Zhao et al, ). Enterocin A (entA) is a class 2a bacteriocin isolated from E. faecium CTC492 and shows inhibition of E. faecalis, Pediococcus, Listeria , and some strains of E. faecium (Aymerich et al, ).…”