Isolation, purification and characterization of bioactive surfactant from the probiotic bacterium Lactobacillus casei NM512 isolated from infant microbiota

Abstract

Background Lactobacillus casei NM512 was previously isolated from the feces of breast-fed infants and has great potential for probiotic treatment of diseases that are based on immune deregulation. These strains fulfill the main criteria required for safe human consumption and could therefore be useful in pharmaceutical and therapeutic preparations. However, further studies are needed to evaluate and decipher the in vivo activities of the isolated strains with regard to their immunomodulatory function. Objective This work aims to isolate, identify and characterize the bioactive surfactant component from the probiotic bacterium L. casei NM512. Materials and methods The isolation of the surfactant from L. casei NM512 was performed after incubation the strain for 72 h at 37°C with shaking at 120 rpm. The surfactant extracted from cells by acid precipitation. A combination of different methods (TLC, FT-IR, NMR, and GC mass) was used to analyze the composition of the isolated surfactant. The surfactant was also investigated for its antimicrobial activity using the well agar diffusion method, antioxidant ability targeting the DPPH free radical, Cytotoxicity ability using MTT assay, and anti- inflammatory activity was done by determination the inhibition of nitric oxide (NO) production in RAW 264.7 macrophages. Results and conclusion The obtained data show that the surfactant is a mixture of carbohydrates, lipids and proteins with glycolipopeptide nature that expressed remarkable antibacterial and antioxidant activities. Furthermore the isolated surfactant showed safety by keeping the cell viability and anti-inflammatory activity. Here we introduce a novel biosurfactant for medical and pharmaceutical purposes.