Partial Characterisation of Bacteriocins Produced by Bacillus cereus Isolates from Milk and Milk Products

Karmen Godič Torkar* and Bojana Bogovič Matijašić

Zootechnical Department, Biotechnical Faculty, University of Ljubljana, Groblje 3, SI-1230 Domžale, Slovenia

Article history:

Received: January 15, 2003
Accepted: April 24, 2003

Key words:

bacteriocins, Bacillus cereus, milk, milk products, SDS-PAGE electrophoresis


Thirty one (19.2 %) out of 161 Bacillus cereus isolates from raw milk and milk products were found to produce proteinaceous substances which inhibit the growth of other B. cereus isolates. The detection of antibacterial activity depended on medium and method used. Bactericidal activity was detected in 23 (14 %) or 19 (12 %) of the tested strains on the triptic soya agar and brain-heart infusion with glucose, respectively, while 11 (7 %) of the strains produced bactericidal substances on both media. Nineteen percent of isolates from raw milk and 20 % of isolates from milk products were found to produce bacteriocins. Four B. cereus isolates inhibited the growth of individual test strains belonging to B. licheniformis, B. subtilis, Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Lactobacillus helveticus and L. casei species. The bacteriocins of four B. cereus isolates were studied in more detail. The production and activity of these substances were detected in stationary- phase of bacterial culture. Two of them were stable after heating at 60 °C, while only one was stable after heating at 75 °C for 15 minutes. All of them were active over a range of pH=3–10. The apparent molecular weights of four bacteriocins detected by SDS-PAGE electrophoresis were in the range of 1 to 8 kDa.

*Corresponding author: 
                                               ++386 (0)1 7217 906
                                               ++386 (0)1 7214 074

Follow us

 facebook 1 twitter bird_icon LI In Bug


Environmental Policy

sdg publishers compact 4 300x300

QR Code


We use cookies to improve our website and your experience when using it. Cookies used for the essential operation of the site have already been set. To find out more about the cookies we use and how to delete them, see our privacy policy.

I accept cookies from this site.

EU Cookie Directive Module Information