Electrospinning as a novel strategy for the encapsulation of living probiotics in polyvinyl alcohol/silk fibroin

The probiotic Lactobacillus plantarum (L. plantarum) were encapsulated with polyvinyl alcohol (PVA) and polyvinyl alcohol/silk fibroin (PVA/SF) nanofibers by electrospinning, respectively. Actually, different concentrations of PVA and SF have significant influence on the morphology of nanofibers, the optimized condition is 6% (w/w) SF and 8% PVA mixed. The L. plantarum on the nanofibers were characterized by scanning electron microscopy (SEM). The different features of PVA/L. plantarum and PVA/SF/L. plantarum nanofibers were proved by thermogravimetric (TGA) and Fourier transform infrared spectroscopy (FTIR). Microbiological tests showed that PVA/SF/L. plantarum exhibited increased survival rates evidently, after being treated in artificial gastric juice at 37 degrees C for 2 h, and the optical density (OD) value in stable growth period was 2.75, compared with free L. plantarum. The results of this study suggest a novel encapsulation approach that protects probiotic cells during their exposure to adverse environmental and intestinal conditions.