the present invention provides variant strains mass - producing εpl which are obtained by variant treatment of a strain producing εpl . for using the variant strains , the strains are cultured in a cultivated medium , εpl is mass - produced and stored in the culture solution , and the stored εpl is collected from the solution . for producing εpl , a strain which produces εpl is variant - treated , the obtained variant strain is cultivated in a culture medium to which l - lysine or l - lysine and one or more sugars are added , εpl is mass - produced and stored in the culture solution , and the stored εpl is collected from the solution . the variant strains producing εpl in large quantities are preferably the strains which have tolerance to an analogue of l - lysine of streptomyces albulus subsp . lysinopolymerus no . 346 - d strain and plasmid - amplifiable variant strains of the same bacteria .