شناسایی ریزسازواره های نمونه های دوغ صنعتی ایرانی

Doogh is a traditional Iranian fermented milk drink, which is produced by lactic fermentation of pasteurized milk. In order to isolate and identify the microorganisms present in Iran industrial Doogh samples, polymerase chain reaction (PCR) was applied. Doogh samples were 17 name brands. After conducting the preliminary identification by microscopic observations and biochemical tests, in order to verify the obtained results the samples were pure-cultured which was followed by PCR and sequencing. According to the results obtained through sequencing of 16S rRNA, the identified bacteria belonged to lactic acid bacteria (Lactobacillus brevis, L. fermentum, L. paracaseiand L. gallinarum); gram-posetive spore-forming bacteria (Bacilluslicheniformis, B. anthracis and B. subtilis) and acetic acid bacteria (Acetobacter tropicalis and A. indonesiensis). Moreover, based on the results obtained by sequencing of D1/D2 26S rDNA the identified yeasts were including Pichia fermentans, Saccaromyces unisporous and Cryptococcus magnus. The obtaining of present study illustrated that in addition to identified non-starter lactic acid bacteria, other types of bacteria and yeasts were found in Iran industrial Doogh samples.