The present invention provides a new strain gene sequence 5 encoding lantibiotic, salivaricin 9 (Sal9) produced using S. salivarius strain NU10. This strain has a novel gene sequence which has been reported for first time using 16S rDNA method and the gene sequence has been deposited into the NCBI database. Sal9 produced by strain S. salivarius NU10 isolated from a Malaysian subject was produced in liquid medium using an induction method. The purification method used to recover Sal9 was XAD-16 chromatography followed by cation exchange chromatography and showed to have a molecular weight of 2560 Da. Sal9 was found to retain biological stability when exposed to high temperature between 90°C to 100°C and stayed bioactive at pH ranging 2 to 10 and was found to lose all antimicrobial activity when treated with proteinase K or peptidase but remained active when treated with lyticase, catalase and certain detergents. Sal9, displayed bactericidal and bacteriolytic activity against and induced cytoplasmic membrane permeability in susceptible bacterial cells. Pore formation activity was detected in sensitive strains incubated with Sal9. This mechanism of antimicrobial action of the lantibiotic Sal9 can be used as a platform to assist with development of new antimicrobials and probiotics produced by S. salivarius that can be used to enhance the health of human oral cavity and upper respiratory tract in this era of increasing antibiotic resistance.