Characterization of lactic acid bacteria isolated from Bukuljac, a homemade goat's milk cheese

Int J Food Microbiol. 2008 Feb 29;122(1-2):162-70. doi: 10.1016/j.ijfoodmicro.2007.11.075. Epub 2007 Dec 4.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Typing Techniques
  • Catalase / metabolism
  • Cheese / microbiology*
  • Colony Count, Microbial
  • DNA, Bacterial / analysis
  • Electrophoresis, Agar Gel / methods
  • Fermentation
  • Food Microbiology*
  • Goats
  • Humans
  • Lactobacillus / classification
  • Lactobacillus / growth & development
  • Lactobacillus / isolation & purification*
  • Lactobacillus / metabolism
  • Milk / microbiology
  • Phylogeny

Substances

  • DNA, Bacterial
  • Catalase