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ANTIBAKTERIJSKI UTICAJ EKSTRAKTA BELOG LUKA NA ESCHERICHA-U
COLI

ANTIBACTERIAL ACTIVITY OF GARLIC EXTRACT ON ESCHERICHA COLI

SIMONA PEROVIĆ Učenica I razreda Trinaeste beogradske gimnazijeRegionalni centar za
talente Beograd IIMentori: TANJA ŢIVANOVIĆ, apsolvent Biološkog fakulteta Jelena Štulić,

master studije, Biološki fakultet

REZIME

Beli luk (Allium sativum) je veoma cenjena povrtarska i lekovita biljna vrsta. Za hemijski sastav belog
luka karakterističan je visok sadržaj suve materije (35-40%) i visok sadržaj eteričnih ulja čiju osnovu čini
alicin. Svrha i cilj istraživanja je antibakterijsko dejstvo belog luka. Ispitivano je dejstvo ekstrakta belog
luka različitih koncentracija na gram-negativnu bakteriju Escherichia-u coli. Korišćen je disk difuzioni
metod antibiograma. Zasniva se na principu difuzije ekstrakta belog luka kroz čvrstu hranjivu podlogu
(agar) na kojoj su bakterije predhodno gusto zasejane. Uočavamo da koncentracija ekstrakta belog luka
postepeno i radijalno opada sa udaljavanjem od diska sve do tačke gde više nije inhibitorna i gde se
pojavljuje porast bakterija. Kao kontrola korišćen je hloramfenikol kako bismo bili sigurni da naše
bakterije nisu mutirale ili postale na neki drugi način rezistentne. Na osnovu okrugle zone oko diska u
kojoj nema vidljivog porasta bakterija zaključujemo da beli luk ima antibakterijsko dejstvo.

Kljuĉne reĉi: beli luk, Escherichia coli, alicin, antibakterijsko dejstvo, inhibicija

SUMMARY

Garlic (Allium sativum) is a highly recognized medicinal vegetable. A characteristic of the chemical
composition of garlic is a high percentage of dry mattere (35-40%) and a high concentration of essential
oils, primarily allicin. The purpose and goal of the research is the antibacterial effect of garlic. The effect
of garlic extract of different concentrations has been tested on gram-negative bacteria Escherichia coli. A
disc diffusion method of antibiogram was used. It is based on the principal of diffusion of garlic extarct
throught a solid nutritious surface on which the bacteria have been previously densely seeded. We observe
that the concentration of a garlic extract gradually and radially decreases with increased distance from the
disc up to the point where it is no longer inhibitory and the numbers of bacteria are higher.
Chloramphenicol was used as a control to make sure our bacteria hadn't mutated or became resistant in
any other way. Based on the circular area around the disc in which there was no notable growth of bacteria
we conclude that garlic has an antibacterial effect.

Key words: garlic, Escherichia coli, allicin, antibacterial effect, inhibition