Screening and identification of lactic acid bacteria strain with oxygen tolerance ability

The purpose of this study was to find a strain which could undergo respiration metabolism, thereby establish the foundation of improvement of oxygen tolerance and survival rate during the production of probiotics. Firstly, heme was added into medium and aerobic environment was provided, ten available strains were investigated to find strains which could undergo respiration metabolism, then API 50 CH identification system and phylogenetic analysis of 16 S r DNA were used to identify the strain selected, finally the growth curve of the screened strain was measured during the fermentation and respirative metabolism. Results showed that the strain Kmh L3 could undergo aerobic respiration which was identified as Enterococcus faecalis, compared with the strain Kmh L3 cultivated under fermentation condition, the biomass and p H of which undergo aerobic respiration increased significantly.