Isolation and evaluation of lactic acid producing bacteria isolated from the rumen of Mehraban sheep

Rumen acidosis can be caused by overeating of readily fermentable carbohydrate, and as a result an imbalance may be seen in rumen microbial population. In order to characterization of lactate producing bacteria 30 isolates were collected from ruminal fluid of three male Mehraban sheep (receiving a diet containing 60% concentrate and 40% alfalfa hay) using specific cultural media. The isolates were evaluated based on gram staining, catalase activity, indole production test and their ability to ferment some sugars. Identification of isolates was undertaken using 16s rRNA gene sequences. A RFLP procedure was used to test the genetic homogeneity of isolates. Four isolates were selected and their 16s rRNA were sequenced. Based on information obtaind from Gene Bank, the isolates were closely (>99%) related to Streptococcus macedonicus, Streptococcus luteciae, Enterococcus faecalis and Escherichia fergusonii.