a strain of enterococcus mundtii has probiotic qualities . the strain of e . mundtii produces an antimicrobial peptide which exhibits antimicrobial activity against a broad range of bacteria . an isolated nucleotide sequence codes for the antimicrobial peptide . a process is also provided for the production of a peptide which comprises cultivating enterococcus mundtii strain st4sa in a nutrient medium under micro - aerophilic conditions at a temperature of between 10 ° c . and 45 ° c ., until a recoverable quantity of the peptide is produced , and recovering the peptide . the isolated peptide may be used as an antimicrobial agent in a liquid formulation or a gel formulation as a topical treatment and may also be used as an antimicrobial agent following encapsulation in a polymer .