Characterization of lactic acid bacteria isolated from Bukuljac, a homemade goat's milk cheese.
The Bukuljac cheese is traditionally homemade cheese, produced from heat-treated goat's milk without the addition of any bacterial starter culture. The presence of lactic acid bacteria (LAB) in Bukuljac cheese has been analyzed by using a polyphasic approach including microbiological and molecular methods such as rep-PCR with (GTG)5 primer. Lactobacillus paracasei subsp. paracasei represents a dominant strain in the microflora of analyzed cheese. Out of 55 Gram-positive and catalase-negative isolates, 48 belonged to L. paracasei subsp. paracasei species. Besides lactobacilli, five Lactococcus lactis subsp. lactis and two Enterococcus faecalis were found. Results of PCR-denaturing gradient gel electrophoresis (DGGE) of DNA extracted directly from the fresh cheese revealed the presence of Leuconostoc mesenteroides. Only lactobacilli showed a high proteolytic activity and hydrolyzed alpha(s1)- and beta-caseins. They are also producers of diacetyl. In addition, 34 out of 55 isolates, all determined as lactobacilli, showed the ability of auto-aggregation. Among 55 isolates, 50 also exhibited antimicrobial activity.
Nikolic
Milica
M
Institute of Molecular Genetics and Genetic Engineering, Vojvode Stepe 444a, PO Box 23, 11010 Belgrade, Serbia. lab6@eunet.yu
Terzic-Vidojevic
Amarela
A
Jovcic
Branko
B
Begovic
Jelena
J
Golic
Natasa
N
Topisirovic
Ljubisa
L
D000818:Animals; D015373:Bacterial Typing Techniques; D002374:Catalase / Q000378:metabolism; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D004587:Electrophoresis, Agar Gel / Q000379:methods; D005285:Fermentation; D005516:Food Microbiology; D006041:Goats; D006801:Humans; D007778:Lactobacillus / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D008892:Milk / Q000382:microbiology; D010802:Phylogeny
D004269:DNA, Bacterial; D002374:Catalase