Total of 33 isolates of lactic acid bacteria from different
samples (Dairy products, Pickles), were isolated and identified
according to the common characteristics of lactic acid bacteria.
Twinty-five isolates were rods and 9 were cocci.
Some quality indicators were studied , such as lactic acid bacteria and
probiotic count during and after the preservation period .
Fifty eight isolates of lactic acid bacteria were obtained from different
local fermented foods. Isolates were identified using microscopic, cultural and
biochemical tests using API strips. Results showed that 44.83% of the isolates
were rod shape
d and 55.17% belonged to cocci bacteria.
Four strains of lactic acid bacteria (LAB) from different genus، species and
sources were tested for their abilities to bind of AFM1 for 14 hours.
Lactobacillus rhamnosus LC705 showed higher ability to bind AFM1 (88.35%)،
followed by Bifidobacteri
um bifidum BG1 (84.21%), Lactobacillus bulgaricus
R21 by 80.41% and finally Streptococcus thermophilus by 71.52% after 14
hours of incubation.
Thirty strains of lactic acid bacteria were isolated from different local
fermented foods. Isolates were identified by using morphological, cultural and
biochemical tests using the API 50-CHL and API 20 Strep systems. Preliminary
characterization
tests showed that 33.33% of the isolates were rod shaped and
66.67% belonged to cocci bacteria.
This research was conducted at the Faculty of Agriculture, Department of
Food Science laboratories to isolate lactic acid bacteria from some Syrian milk
products (milk, yogurt, cheese) and determine some morphological,
physiological characteristic and the ability of these isolates to ferment sugars.
The research aimed to study the contrast between three commercial starter
cultures used in the manufacturing of fermented meat and different
concentrations of nitrite, salt, lactic acid and black pepper all alone on the
impact of inhibition of the
microbial growth. The first starter culture contained
a mixture of Staphylococcus carnosus and Staphylococcus vitulinus, and the
second one contained Lactococcus lactis and Lactobacillus sakei while the third
one contained Lactococcus lactis, Lactobacillus sakei, Staphylococcus carnosus
and Staphylococcus xylosus. Four concentrations of each additive were
individually prepared and the inhibition activity on the microbial growth was
estimated by comparing the total microbial counts with and without the
addition of the same additive. Analysis of variance and least significant
difference (LSD) test at P<0.05 showed that the lactic acid was the most
influential on the microbial growth of starter cultures, and significant
differences were also detected between the used concentrations of lactic acid,
while no significant effect was observed when 100 ppm of nitrite, 1-3% of salt
and 0.1-0.4% for black pepper were used. Consequently, the previously
mentioned concentrations could be applied in the manufacturing of fermented
meats.
This research aimed to identify the bacteriocin produced from a strain of
Strep. Thermophiles which were isolated from native Syrian white cheese and
to identify its characteristics.
The study showed that the produced bacteriocin is able to inhibi
t the growth
of B.cereus bacteria, while this ability is lost when handling the bacteriocin with
100 degree for more than 60 minute, and is lost too in the presence of
proteinase enzyme k and was affected by the presence of pepsin or trypsin
enzymes. The arbitrary unit was estimated by 200 AU/ml.
The study also showed that the weight of the studied bacteriocin was almost
4 KDA and that was after the sedimentation by ammonium sulfate and the
deportation of Tricine -SDS –PAGE with 15% concentration. When using the
technique of PCR to recognize the bacteriocin and applying the technique of
sconsr, it has been found that bacteriocin produce matches with bacteriocine.
Thermophilin13.
This study was conducted at the laboratory of Food Science Department,
Agriculture College, Damascus University to isolate and characterize of
Lactobacilli bacteria from some Syrian foods and detection the effectiveness of
anti-pathogenic bacteria
l growth. Lactic acid bacteria from different dairy
products, pickles and dried plant samples were isolated and identified
according to common characteristics. Results showed that twenty-three isolates
were rods while only 2 of the them were coccid. These isolates were tested for
their antimicrobial effect against pathogenic bacteria for both gram positive
bacteria (Staphylococcus aureus) and gram negative bacteria (Klebsiella
pneumonia and Escherichia coli). Fifteen isolates demonstrated antimicrobial
effect against the three tested bacteria, of which CP50 and CP46 isolates
showed the best antimicrobial effect. Results of the standard physiological and
biochemical tests identified fourteen isolates as Lactobacillus plantarum and one
isolate as Lactobacillus fermentum.
This research was conducted in the Agriculture Faculty- Food Science
Department, Damascus University, for detecting Lactic acid bacteria isolated
from Syrian dairy products (white fresh cheese-Leben), Samples were collected
from August, 2004 to Oc
tober, 2005 from different areas in Syria. Analysis was
done for 245 bacterial isolates from 40 samples of white fresh cheese and 58
samples of yogurt (curd). Results showed that the genus Enterococcus was
dominant with a percentage of 47.52%; Pediococcus had a percentage of 26.3
%; while Lactococcus had a percentage of 15.38% with only 3.2% for
Lactobacillus.
