JPH0724578B

PURPOSE:To stably enhance production efficiency of nisin by culturing a nisin producing microorganism in a culture medium to which a specific amino acid is added. CONSTITUTION:Nisin producing lactic acid bacterium (A) of SBT 1212 (FERM P 11674) or SBT 1227 (FERM P-11675), etc., belonging to Streptococcus lactis and retaining a nisin producing gene in chromosome is collected by selecting nisin by nisin-sensitive test and nisin producing test, etc. Then one or more kind of amino acid (e.g. serine, phenylalanine or glycine) such as (a) amino acids necessary to rearing of the bacterium 4, (b) amino acids contained in primary structure of nisin, (c) amino acids becoming a precursor of these amino acids in metabolism path is added thereto at an amount of 0.1-10mg/ml to provide a culture medium (B). A cultured mixture obtained by inoculating the culture medium B with the bacterium A and then culturing the bacterium by shake culture is subjected to extraction purification by chloroform extraction method, etc., to produce the nisin.