Author/Authors :
Al-Hashedi, Sallah A. Central Labs - King Faisal University, Al-Hassa, Saudi Arabia , Al-Helali, Mohamed F. Department Biology - Faculty of Science - Sana’a University, Sana’a, Yemen , Al-Zoreky, Najeeb S. Department Food Science and Nutrition - College of Agricultural and Food Sciences - King Faisal University, Al-Hassa, Saudi Arabia , Al-Dalali, Sam S. Department of Food Science and Technology - Faculty of Agriculture - Ibb University, Ibb, Yemen , Al-Hajj, Nabil Q. Marine Science and Biological Research, Aden, Yemen , Algabri, NaifA. Department of Pathology - Faculty of Veterinary Medicine - Thamar University, Yemen , Abd El-Hack, Mohamed E. Department of Poultry - Faculty of Agriculture - Zagazig University, Zagazig, Egypt , Farag, Mayada R. Forensic Medicine and Toxicology Department - Faculty of Veterinary Medicine - Zagazig University, Zagazig, Egypt , Alagawany, Mahmoud Department of Poultry - Faculty of Agriculture - Zagazig University, Zagazig, Egypt
Abstract :
Bacteriocins are ribosomally synthesized antimicrobial polypeptides produced by some bacteria including
selected lactic acid bacteria (LAB). The study conducted survey on traditional fermented dairy products and vegetables
for presence of bacteriocin-producing bacteria. Bacteriocin genic LAB (1.62%) were isolated from samples were
identified according to the standard phenotypical and biochemical tests. The standard well assay using indicator
bacteria (L. monocytogenes ATCC 7644, Staphylococcus aureus ATCC 6538 and Lactococcus lactis subsp. Lactis ATCC
11955) were adopted to evaluate the inhibition spectra of substances produced by Enterococcus and Propionibacterium.
The isolates showed similar or better activity than the nisin against indicators. The active principles produced by isolates
were inhibited by proteases including α-Chymotrypsin. The protein nature of bacteriocins makes them vulnerable to
common proteases of the digestive tract. Bacteriocins of the active isolates were affected by pH (4-6.5) and thermal
treatments (65ο
C for 30 min).
Keywords :
Lactic acid bacteria , Preservatives , Bacteriocins , Food-borne pathogens
