Screening, Identification and Biological Characterization of Weizmannia coagulans BC66

The objective of this study was to isolate and screen probiotics for application in production of microecological preparation. A bacillus strain was screened from the feces of a healthy piglet based on heat treatment and lactic acid-producing characteristics. This strain was identified to be Weizmannia coagulans assigned as BC66 by means of morphological, physiological, biochemical and molecular identification. The strain Weizmannia coagulans BC66 was evaluated in vitro for its probiotic potential viz., the tolerance to gastrointestinal tract conditions (low pH, bile salt tolerance), antimicrobial activity, antibiotic susceptibility. The strain BC66 showed the resistance to low acidity and high bile salts concentration with the survival rate of 98% at pH3.0 and 79% at bile salt 0.3% respectively. The viability of the strain was 92% after 10 min treatment in 90 ℃ water bath. Moreover, the strain was able to act against Escherichia coli and Salmonella and was sensitive to most of the antibiotics tested. Strain BC66 did not exhibit any hemolytic activity. The results indicated that Weizmannia coagulans BC66 had excellent probiotic properties. This strain could be used as a potential candidate probiotic and eventually be explored further for potential application in feed additives.