A method of preventing biofilm formation in an environment including the steps of administering to the environment an effective amount of a peptide having the amino acid sequence NH.sub.2-lys-lys-val-val-phe-lys-val-lys-phe-lys-CONH.sub.2 [SEQ ID NO: 1] The method is useful in preventing the formation of biofilms in various environments including a home, workplace, laboratory, industrial environment, aquatic environment, animal body or human body. A method of inhibiting the growth of oral microorganisms including the steps of administering to an oral environment an effective amount of a peptide having the amino acid sequence NH.sub.2-lys-val-val-phe-lys-val-lys-phe-lys-CONH.sub.2 [SEQ ID NO: 1].