Isolation, Identification of Lactobacillus mucosae AN1 and its Antilisterial Peptide Purification and Characterization Ayyanna Repally 1 & Venkatesh Perumal 1 & Ankaiah Dasari 1 & Esakkiraj Palanichamy 1 & Arul Venkatesan 1 # Springer Science+Business Media, LLC 2017 Abstract Lactobacillus mucosae strain AN1 isolated from sheep milk and characterized for its probiotic suitability. In vitro evaluation of critical gut endurance properties of this strain were assessed by different screening methods such as bile salt, gastric acid, lysozyme tolerance assays, hemolytic, cholesterol reduction properties, and HT-29 cell line adhesion assay. Antibacterial peptide from this strain was purified using ammonium sulphate precipitation, gel filtration chromatogra- phy and reverse-phase HPLC. The molecular mass of peptides was determined by Tricine-SDS-PAGE and confirmed by matrix-assisted laser desorption ionization-time of flight mass spectroscopy (MALDI-TOF-MS). Purified peptide was named as AN1 having a molecular mass of 10.66 kDa. Helical structures of peptide were determined using circular dichroism spectroscopy. Stability of peptide AN1 towards dif- ferent parameters such as pH, temperature, organic solvents, proteolytic, and glycolytic enzymes was also analyzed. Keywords Sheep milk . L. mucosae AN1 . Beneficial bacteria . Antilisterial property . Foodpreservation . Agri-food industry Introduction Antibiotics have been included in animal feed at sub- therapeutic levels, acting like growth promoters and to prevent several diseases. Development of antimicrobial resistance and transfer of antibiotic resistance genes by pathogenic bacteria exhibits a serious problem in the food industry. So there is a need to find alternative methods to control and prevent food pathogens [1]. Preservation food using probiotics has been recommended as a better alternative method to avoid bacterial spoilage. The Joint Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO) working groups, defined probiotics as live microor- ganisms which are administered in adequate amounts, confer beneficial health effects on the host organism [2]. The search for new probiotic strains isolated from natural resources and fermented food products with promising health and techno- logical properties to be applied in the food processing industry and it has been a prominent research area since, several de- cades. In order to be applied as probiotics in food products and pharmaceutical formulations, a probiotic should be able to survive at processing operations and storage. In vitro assays could enable a preliminary screening for probiotic potential and its attributes, such as resistance to gastrointestinal condi- tions, ability to deconjugation of bile salts, and adhesion prop- erties to the intestine [3]. Among the various strains of Lactobacillus sp., it has been extensively studied for its pro- biotic suitability. Lactobacillus sp. has better antibacterial and antifungal activities which could be useful for therapeutic ap- plications in Agri-food industries [4]. Adhesion to intestinal mucus is a desirable property, as it increases persistence in the intestine and ability to effective colonization [ 5 , 6]. Lactobacillus mucosae strains have the ability to adhere intes- tinal epithelial cells and inhibit pathogens in human gastroin- testinal tract [7]. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12602-017-9341-3) contains supplementary material, which is available to authorized users. * Arul Venkatesan varul18@gmail.com 1 Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry 605014, India Probiotics & Antimicro. Prot. https://doi.org/10.1007/s12602-017-9341-3