Screening and Identification of Biosurfactant-Producing Lactic Acid Bacteria

Biosurfactant attracts people’s attention because of its advantages of green and low toxicity. Lactic acid bacteria are beneficial to human and animal health. In order to make the application of surfactants safer, SDS standard curve was established, 65 strains of Lactic acid bacteria were used as screening source, and oil expanding circle was used as index to screen the strain with strong surfactant production capacity. The results showed that the standard curve of SDS was Y=34.82+(-1495.97) X₁+33.11X₂, and all strains had the ability to produce surfactants. Surface activity varied with bacteria. The concentration of surface activity ranged from 111.15mg/L to 736.23 mg/L. The concentration of BS in supernatant of LB6, 49, F70, 20 and Y1 strains was selected for screening. The concentration of BS in supernatant was 561.01~935.77 mg/L, and the concentration of BS on cell surface was 401.67~1076.94 mg/L. Considering the highest BS-producing strain is F70, the result of 16SrDNA showed that the strain is Pediococcus acidilactici F70. This experiment provides basic data for the production of surfactants by Lactic acid bacteria.