Gram-negative microorganisms isolated from fish and their sensitivity against essential oils

Essential oils may inhibit Gram-negative microbiota, a causative agent of spoilage of fresh fish. The aim of this study was to detect antibacterial activity of essential oils against Gram-negative bacteria isolated from fish. The antimicrobial activity of Citrus paradisi peel oil, Citrus reticulata peel oil, Juniperus communis fruit oil, Eucalyptus globulus leaf oil and Cananga odorata flower oil was studied. The microorganisms tested were Pseudomonas fluorescens, P. frederiksbergensis, P. gessardii, P. ludensis, P. proteolitica, Shewanella baltica, Yersinia ruckeri and Y. enterocolitica. Essential oils were tested with disc diffusion method and method of minimal inhibition concentration. The best antimicrobial activity of Cannaga odorata flower peel oil and Juniperuss communis fruit oil was found against Pseudomonas spp. and less against Shewanella baltica, Yersinia ruckeri and Y. enterocolitica. Citrus paradisi peel oil and Citrus reticulata peel oil were most active against Yersinia spp. Eucalyptus globulus leaf oil showed good antimicrobial effect against Shewanella baltica