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Register a new userCharacteristics of Bactriocin produced from Streptococcus thermophiles isolated from native Syrian white cheese
خصائص البكتريوسين المنتج من Streptococcusthermophilus المعزولة من الجبن الأبيض البلدي
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عهد أبو يونس( باحث )
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هدف البحث إلى تعرف البكتريوسين المنتج من سلالة من Thermophilus. Strep المعزولة مـن الجبن الأبيض البلدي السوري و تعرف خصائصه. و قد وجدت الدراسة أن البكتريوسين المنتج قادر علـى تثبيط نمو بكتيريا cereus. B ، إلا أن هذه المقدرة تفقد عند معاملة البكتريوسين بدرجة حـرارة 100 ْ م مدة تزيد على 60 دقيقة، كما أن هذه المقدرة تفقد بوجود أنزيم بروتينـاز k و لا تتـأثر بوجـود أنـزيم الببسين أو التربسين. و قدرت القيمة الاعتباطية (units Arbitrary) بـ 200 ml/AU . و وجدت الدراسة أن وزن البكتريوسين المدروس يقـدر بنحـو KDa 4 ، بعـد الترسـيب بـسلفات الأمونيوم، و الترحيل على PAGE –SDS -Tricine تركيز 15 % و عند استخدام تقنية PCR فـي تعـرف البكتريوسـين و إجـراء تقنيـة السكونـسر وجـد أن البكتريوسـين المنـتج يتوافـق مــع بكتريوسين Thermophilin 13.
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 inhibit 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.
References used
Bredholt, S., Nesbakken, T. and Holck, A. (2001). Industrial application of an antilisterial strain of Lactobacillus sakei as a protective culture and its effect on the sensory acceptability of cooked, sliced, vacuum-packaged meats. Int J Food Microbiol 71, 191–196
Cleveland, J., Montville, T. J., Nesr, I.F. and Chikindas, M. L. (2001). "Bacteriocins: safe, natural antimicrobials for food preservation. Int J Food Microbiol 71, 1–20
Daba, H., Pandian, S., Gosselin, J.F., Simard, R.E., Huang, J. and Lacroix, C. (1991). "Detection and activity of a bacteriocin produced by Leuconostocmesenteroides" Appl Environ Microbiol 57, 3450–3455
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This study aimed to investigate the possibility of rapid identification of
isolated bacteria Leuconostoc from Syrian white fresh cheese made of cow and
ewe milk using Fourier transform infrared spectroscopy (FTIR). 20 isolates (14
from ewe milk ch
eese and 6 from cow milk cheese) were isolated. These isolates
were pretasted with PCR technique using specific primers. Results indicated
that these isolates are belonged to the genus Leuconostoc and 12 of them are
belonged to Ln. mesenteroides species. The results of FTIR technique showed in
comparison to device library that all isolates are belonged to genus
Leuconostoc, and 4 of these isolates are belonged to Ln. citreum species which
could not be identified using PCR method (with the used primers), and helped
to identify the following subspecies: Ln.mesenteroides subsp mesenteroides and
Ln. mesenteroides subsp dextranicum while PCR technique described them
belonging only to a Ln. mesenteroides species. Moreover, FTIR technique was
able to give the results within 25 hours, thus it can be used in identification of
food bacteria more quickly.
The objective of this investigation was the Identification of Salmonella spp.
isolated from white cheese (traditional processed from sheep milk) and classify
it by using API 20E and PCR techniques.
80 samples of white cheese (traditional processed
from sheep milk) were
collected from different locations in Syria.
According to PCR technique, 17 samples gave positive result for salmonella
meaning that 21.25 % did not match the levels of the Syrian Standardization
and Metrology (S.S.M.).
According to API 20E technique, the dominat type of Salmonella was
Salmonella Arizona (47%), followed by Salmonella typhim (23.61 %),
Salmonella paratyphi (17.6 %) and Salmonella spp. (11.76 %).
Results showed that samples from local cheese positive for Salmonella were
much more than samples from Akkawi cheese.
The results showed that the PCR technique is fast and accurate and can be
used to Identify Salmonella in cheese.
This study aimed to manifactor white cheese using bovine milk
retentate and concentrated with Ultrafiltration using (Frames &
plates) system, and compared it with white cheese made from
original milk in terms of chemical composition, cheese yield,
sensory characteristics.
In this paper, we evaluated some varieties of local white cheeses (Baladi and
Akkawi). 100 samples were collected randomly from various production sites in
Syria between 2003 and 2004. Chemical and microbiological analyses were
applied to determin
e their suitability to the Syrian standards. This study shows
that their quality do not fulfill the set minimum Syrian quality standards. The
microbiological analyses (Coliform, Escherichia, Staphylococcus aureus, and
Salmonella), rate was 75% for Coliform organisms and 66% for Escherichia in
Baladi, while it decreased to 43% for Coliform and 25% for Escherichia in
Akkawi. As concerns the positive coagulation bacteria (S. aureus), the rate
exceeded 15% for both types of cheeses. 18% and 12% of Salmonella were
found in Baladi and Akkawi also respectively. Various types of Coliform and
Salmonella were identified. This study indicated that local cheeses have no
uniform or standardized chemical characteristics. The averages of acidity,
moisture content and salt percentage were 0.24%, 60%, and 2.6%, for Baladi
and 0.28%, 53.53%, and 9.96% for Akkawi, respectively. The fat content had a
wide range for all cheese samples. This study classified these fresh cheeses as
raw cheeses that have vast flora and no uniform chemical and quality
characteristics. The above findings, lead to different defects and properties
which do not fulfill the Syrian quality standards. Thus, the quality of Syrian
cheeses varieties is still questionable.
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were collected during the years 2012-2013 where 13 were isolated from soil, 23
from tree leaves and 14 from food. The isolates AUX system. Were classified
into three Rhodoto
rula species: R. mucilaginosa, R. glutinis and R. minuta with
76%, 20% and 4% respectively using API 20c. Six methods were applied in
breaking down the yeast cells and extracting the carotenoids. It was shown the
quantity of carotenoides extracted with the modified method by adding DMSO
to the yeast biomass and incubating for 24 hrs at 4˚C yielded in higher
quantities when compared with the other five methods. All isolates were able to
produce carotenoides but they varied in their efficiency where the isolate A24
(R.mucilaginosa) isolated from food was distinguished by its high level of
production which reached 658.23 μg/g dry weight compared with the others.
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