Antimicrobial effects of the essential oils of basil populations (Ocimum basilicum l.) in Serbia

Abstract

Since pathogen microorganisms can be found in food, natural antimicrobial compounds, like ethereal oils, are of great interest in food preservation. The aim of the study was to evaluate antimicrobial activity of ethereal oils extracted from 10 basil species in Serbia against food borne microorganisms. In studying antimicrobial effects of essential oils the following microorganisms were used: Gram negative bacteria-Escherichia coli ATCC 25922 and Salmonella enteritidis ATCC 31806, Gram positive bacteria-Bacillus cereus ATCC 11788 and Staphylococcus aureus ATCC 25923, yeasts-Candida albicans ATCC 24433 and Saccharomyces cerevisiae ATCC 9763 and mold Aspergillus niger. Screening of essential oils antimicrobial activity was done using the disk diffusion method with various concentrations of oil (pure oil, suspensions with alcohol in concentrations 2:1, 1:1, 1:2 and 1:3, 1:4 and 1:5). The best antimicrobial effect was observed in the essential oil from basil T-10 which exerted microbistatic effect on bacteria Escherichia coli ATCC 25922 (inhibitory zone 7mm) and Bacillus cereus ATCC 11788 (inhibitory zone 4.66mm) when applied in suspension with alcohol in concentration 1:5 (1ml essential oil:5ml 96% C2H5OH). Significant microbistatic effects on yeast Candida albicans ATCC 24433 was observed in tests with essential oils from basil T-8 (suspension 1:1 with alcohol, inhibitory zone 41.67mm) and basil T-6 (suspension 1:1 with alcohol, inhibitory zone 41mm). .

Kako patogeni mikroorganizmi iz različitih izvora mogu da dospeju u prehrambene proizvode, upotreba prirodnih anti-mikrobnih komponenata, kao što su etarska ulja, veoma je važna za zaštitu namirnica. Cilj ovog rada bio je da se potvrdi antimikrobna aktivnost etarskih ulja ekstrakovanih iz deset populacija bosiljka iz Srbije na određene mikroorganizme zagađivače hrane. Za ispitivanje antimikrobnih efekata etarskih ulja korišćeni su sledeći mikroorganizmi: Gram negativne bakterije-Escherichia coli ATCC 25922 i Salmonella enteritidis ATCC 31806, Gram pozitivne bakterije-Bacillus cereus ATCC 11788 i Staphylococcus aureus ATCC 25923, kvasci-Candida albicans ATCC 24433 i Saccharomyces cerevisiae ATCC 9763 i plesan Aspergillus niger. Antimikrobni uticaj etarskih ulja posmatran je pomoću metoda difuzije sa filter - diskova u prisustvu nekoliko različitih koncentracija ulja (čisto ulje, suspenzije sa alkoholom u koncentracijama 2:1, 1:1, 1:2 i u nekim slučajevima 1:3, 1:4 and 1:5). Najbolji antimikrobni efekat uočen je kod ulja dobijenog iz bosiljka T-10 koje je u suspenziji sa alkoholom u koncentraciji 1:5 (1ml etarskog ulja:5ml 96% C2H5OH) delovalo mikrobistatički na bakterije Escherichia coli ATCC 25922 (sa zonom inhibicije 7mm) i Bacillus cereus ATCC 11788 (sa zonom inhibicije 4.66mm). Na kvasac Candida albicans ATCC 24433 značajan mikrobistatični efekat imala su ulja bosiljka T-8 (suspenzija 1:1 sa alkoholom, zona inhibicije 41.67mm) i bosiljka T-6 (suspenzija 1:1 sa alkoholom, zona inhibicije 41mm). .