الفهرس Only 14 pages are availabe for public view
 |  | from | 108 |  |  |
| | | from | 108 | | |
Abstract
Lactic acid bacteria have contributed over the centuries in preserving food
and preventing food poisoning. This study was carried out in two parts.
Isolation and identification of lactic acid bacteria (LAB) were carried out
from different Egyptian dairy products, as well as the antibacterial activity
of the isolated cultures against growth of Bacillus (B). cereus, B. subtilis, B.
jirmus, B. cereus var. mycoids, Staphylococcus (Staph.) aureus and
Enterobacter aerogenes was examined in the first part, while using of the
highest antibacterial activity of LAB isolates as protective starter cultures
during manufacturing of fermented milk, Tallaga cheese and Ras cheese
was the aim of the second part. The results were as follows:
1. 717 bacterial isolates were isolated from Egyptian dairy products. 263
were identified as LAB isolates. 75 of them resulted in antibacterial activity
against one or more of target bacteria. Three isolates [Lactobacillus (Lb.)
spp. 55, Lb. spp. 64 and Lb. spp. 66] appeared antibacterial activity against
all of the target bacteria and selected for further studies.
2. The antibacterial activity was due to formation of organic compounds
(H202, organic acids, diacetyl, ethanol and unknown organic compounds).
3. Lactobacillus spp. isolates were used as protective starter cultures during
the manufacture of fermented skim milk, Tallaga-like and Ras-like cheese to
inhibit the growth of B. cereus and Staph. aureus. The microbiological
properties of dairy products were also improved.