Zbornik - Društvo genetičara Srbije
Zbornik - Društvo genetičara Srbije
Zbornik - Društvo genetičara Srbije
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26 ZBORNIK ABSTRAKATA III KONGRESA GENETIÈARA SRBIJE I-Pos-5<br />
Subotica, 30. novembar - 4. decembar 2004.<br />
IZOLACIJA I KARAKTERIZACIJA BAKTERIJA<br />
MLEÈNE KISELINE IZ RADANSKOG SIRA<br />
Nataša Jokoviæ 1 , Maja Vukašinoviæ 2 i Lj. Topisiroviæ 3<br />
1<br />
Tehnološki fakultet, Leskovac<br />
2<br />
Tehnološko-metalurški fakultet, Beograd<br />
3<br />
Institut za molekularnu genetiku i genetièko inenjerstvo, Beograd<br />
Iz kravljeg i ovèijeg mleka kao i iz uzoraka sira tokom zrenja (5, 10, 20, 30 i 60 dana)<br />
izolovano je 118 izolata bakterija mleène kiseline (BMK). Kao selektivna podloga<br />
korišæene su: GM17 podloga za laktokoke, MRS podloga za laktobacile i MSE podloga<br />
za leukonostoke. Na osnovu mikrobioloških i fizioloških testova izolati su identifikovani<br />
do nivoa vrste. Vrste Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides i<br />
Enterococcus faecium izolovane su iz uzoraka mleka i sira, dok su vrste Lactobacillus<br />
plantarum, Lactobacillus paraplantarum, Lactobacillus brevis i Eterococcus fecalis<br />
izolovane samo iz sira. Korišæenjem mikrobioloških i fizioloških testova 20% izolata nije<br />
bilo moguæe identifikovati. Analiza plazmidnog profila i ispitivanje proteolitièke<br />
aktivnosti uraðeno je za 73 odabrana izolata. Veæina izolata Lactococcus lactis subsp.<br />
lactis kao i homofermentativni laktobacili pokazuju dobru proteolitièku aktivnost, dok su<br />
izolati iz rodova Leuconostoc i Enterococcus slabi proteoliti. Plazmidi su detektovani<br />
kod veæine izolata i plazmidni profili pokazuju varijabilnost.<br />
ISOLATION AND CHARACTERIZATION OF<br />
LACTIC ACID BACTERIA FROM RADAN'S CHEESE<br />
In this study we described characterization of 118 natural isolates of lactic acid bacteria<br />
(LAB) from cow's milk, ewe's milk and cheese (samples were taken after 5, 10, 20, 30<br />
and 60 days of ripening). The isolates were selected using selective media for LAB,<br />
GM17 for lactococci, MRS for lactobacilli and MSE for leuconostoc. Identification of<br />
strains to the species level was performed by the analysis of their carbohydrate fermentation<br />
pattern and by their physiological characteristics. Lactococcus lactis subsp. lactis,<br />
Leuconostoc mesenteroides and Enterococcus faecium were found in milk and cheese,<br />
while Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus brevis and<br />
Enterococcus faecalis were found only in cheese samples. Twenty percent of isolates<br />
were not determinated by used tests. Isolation of plasmids and examination of proteolytic<br />
activity were done for 73 isolates. The most strains of Lactococcus lacts subsp. lactis and<br />
homofermentative lactobacilli exhibited high proteolytic activity towards b-casein, while<br />
strains from genus Leuconostoc and Enterococcus showed weak proteolytic activity. The<br />
analysis of plasmid profiles revealed that majority of strains containe different plasmids.