Bacteriocin-like inhibitory substance (BLIS) produced by Enterococcus faecium MA115 and its potential use as a seafood biopreservative

Introduction: Listeria monocytogenes is an opportunistic foodborne pathogen that can cause death to infected humans. The bacterial pathogen was fre quently associated with food-borne origins including seafood. Thus, the present study aimed at screening anti-listeria-producing lactic acid bacteria (AL-LAB) iso lated from the intestinal tracts of wild gilt-head seab ream (Sparus aurata). Materials and Methods: Lactic acid bacteria (LAB) were isolated from the intestinal tracts of 15 wild gilt-head seabreams andscreenedfor antimicrobial activity against Listeria monocytogenes. LAB isolated with the strongest anti-listerial activity was identified and further character ized for its anti-listerial compounds, followed by testing its protecting capacity on experimentally contaminated salmon fillets. Results: Three out of 52 LAB showed antagonistic activ ities against the foodborne pathogen. Of these 3, an isolate with the strongest inhibitory activity was obtained from strain MA115 (>400AU). Based on its 16S rDNA sequence, strain MA115 had 99% similarity to Enterococcus faecium (Acc. Nb: MG461637.1).Further in vitro assays showed that the anti-listerial compound was very sensitive to proteinase K  * Corresponding author: Muhamad Amin, Department of Aquaculture, Faculty of Fisheries and Marine, Universitas Airlangga, Campus C Universitas Airlangga, Jl. Mulyorejo, Surabaya, East Java 60115, Indonesia, e-mail: muhamad.amin@fpk.unair.ac.id Olumide A. Odeyemi: Research Division, University of Tasmania, Launceston, Australia; HeTA Food Research Centre of Excellence, School of Chemical Engineering, University of Birmingham, Birmingham, UK Fera R. Dewi: Research Centre for Applied Microbiology, National Research and Innovation Agency, Cibinong 16911, Indonesia Christopher M. Burke: Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Launceston, Tasmania 7250, Australia OpenAccess. ©2023theauthor(s), published by De Gruyter. License. which suggested that it is a bacteriocin-like inhibitory sub stance (BLIS). In addition, the BLIS was resistant to a wide range of pH (2–10),andlow(4to−20°C) as well as high temperatures (30−121°C). In addition, the BLIS showed bac tericidal activity on L. monocytogenes in artificially contami nated Salmon fillets stored at 0°C. Conclusion: The BLIS produced by Enterococcus faecium strain MA115 has the potential for application to improve food safety, although further studies are still required to specifically identify the BLIS, for biopreservation purposes.