تعريف و توصيف عزلات محلية من بكتيريا حمض اللبن و اختبار قدرتها على إنتاج ثنائي الأسيتيل

الملخص EN

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 shaped and 55.17% belonged to cocci bacteria.

About 31.03% of cocci isolates belonged to the genus Enterococcus 13.8% to Leuconostoc and 10.34% to Lactococcus.

Rod bacteria represented several species of the genus Lactobacillus.

MH12 isolated from white cheese samples from Damascus countryside region revealed the highest producer of diacetyl (82.84 mg/L)، while MH21 isolated from cow milk from Damascus region was the lowest in production of diacetyl (16.78 mg/L).

Lactobacillus and Lactococcus isolates were intermediary producers.

Twelve isolates of Enterococcus showed diacetyl productive capacity ranging from 18.79 to 82.84 mg/L, while in the genus Lactobacillus only 7 isolates from L.

plantarum.

L.

pentosus and L.

paracasi species were active producers.

L.

fermentum.

L.

brevis and L.

rhamnosus isolates were inactive producers of diacetyl.

Most isolates of Lactococcus and Leuconostoc did not produce detectable diacetyl.