Terminalia ferdinandiana Exell: Extracts inhibit Shewanella spp. growth and prevent fish spoilage

Shewanella spp. are major causes of fish spoilage. Terminalia ferdinandiana (Kakadu plum) extracts were investigated for their ability to inhibit Shewanella spp. growth. Leaf and fruit extracts displayed potent growth inhibitory properties against all Shewanella spp. The methanolic leaf extract was a particularly potent inhibitor of S. putrefaciens (DD MIC 93; LD MIC 73 mu g/mL), S. baltica (DD MIC 104 mu g/mL; LD MIC 85 mu g/mL), S. frigidimarina (DD MIC 466 mu g/mL; LD MIC 391 mu g/mL) and S. loihica (DD MIC 95 mu g/mL; LD MIC 55 mu g/mL) growth. The aqueous and ethyl acetate leaf extracts were also potent growth inhibitors, with MIC values generally substantially < 1000 mu g/mL. Treatment of Acanthopagrus butcheri Munro fillets with methanolic Kakadu plum extracts significantly inhibited bacterial growth for 15 days at 4 degrees C. All Kakadu plum extracts were nontoxic in the Artemia franciscana bioassay. LC-MS analysis identified several compounds which may contribute to the inhibition of Shewanella spp. growth.