Bacteriocins　derived　from　lactic　acid　bacteria　(LAB)　are　well　recognized　as　promising　food　preservative　due　to　high　safety　and　potent　antibacterial　activity　against　foodborne　pathogens　and　spoilage　bacteria.　In　this　study,　an　antimicrobial　agent-producing　strain　FZU63　from　Chinese　sauerkraut　was　identified　as　Lactobacillus　coryniformis　based　on　physio-biochemical　characterization　and　16S　rDNA　sequence　analysis.　In　addition,　a　bacteriocin　was　purified　from　the　culture　supernatant　of　L.　coryniformis　FZU63,　and　its　molecular　mass　was　determined　as　1493.709 Da.　Moreover,　the　amino　acid　sequence　of　the　bacteriocin　was　predicted　to　be　RQQPMTLDYRW-NH2　using　nanoliter/microliter　liquid　chromatography　combined　with　triple　quadrupole-linear　ion　trap　tandem　mass　spectrometry　and　was　named　as　Lactocin　63.　Furthermore,　Lactocin　63　displays　potent　antimicrobial　activity　against　the　tested　Gram-positive　and　negative　bacteria　based　on　the　results　of　determining　MICs.　Subsequently,　the　action　mode　of　Lactocin　63　against　Shewanella　putrefaciens　was　investigated.　The　results　demonstrated　that　Lactocin　63　targets　and　is　adsorbed　onto　the　bacterial　cell　wall　and　membrane　and　then　disrupts　cytoplasmic　membrane,　which　is　leading　to　leakage　of　cytoplasm　according　to　the　results　of　flow　cytometry　analysis　and　the　observation　of　cellular　ultra-structure　using　confocal　laser　microscopy　and　atomic　force　microscopy.　Collectively,　these　results　are　helpful　and　providing　the　theoretical　base　for　developing　and　applying　LAB-derived　bacteriocins　as　promising　bio-preservatives　to　combat　foodborne　pathogens　and　spoilage　bacteria　in　seafood　industries.　Key　points　•　A　bacteriocin-producing　strain　Lactobacillus　coryniformis　was　isolated.　•　A　novel　bacteriocin　produced　by　Lactobacillus　coryniformis　FZU63　was　characterized.　•　Action　mechanism　of　the　bacteriocin　against　S.　putrefaciens　was　elucidated　in　vitro.　©　2021,　The　Author(s),　under　exclusive　licence　to　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.