Extraction of Surface Layer Protein from Lactobacillus acidophilus NCFM and the relationship among SLP and strain acid, bile resistance and cell adhesion

Extraction method of Surface Layer Protein from Lactobacillus acidophilus NCFM with LiCl was optimized.SDS-PAGE was employed to validate the extraction performance, and the optimized condition was that the strain culture was treated with 5mol /L LiCl for 20min at 35℃.After SLP extraction, the activity of strain was remained and the surface protein could reform to the maximum in 8h.The property of SLP reformation was employed to analyze the relationship among SLP and strain acid / bile resistance, and the adhesion of strain to HT-29 cell.The results showed that, after 8h SLP reformation, the acid challenge survival rates of SLP removed strains enhanced from52.5% to 85.9%, and bile challenge survival rates of SLP removed strains enhanced from 43.4% to 81.8%.And the adhesion index to HT- 29 increased from 0.33 to 18.54 after 8h SLP reformation. The indicators related to strain survival in GI track were recovered as the reformation of SLP.In conclusion, the integrity of SLP was important to the survival of Lactobacillus acidophilus NCFM in GI track.