RAPD profiles of Lactococcus lactis wild and reference strains determined using primer M13. Lane 1, molecular size marker λDNA/HindIII; lane 2, M78 (wild Nis+ strain); lane 3, M104 (wild Nis+ strain); lane 4, L. lactis subsp. cremoris LMG 6897T; lane 5, L. lactis subsp. lactis LMG 6890T; lane 6, L. lactis subsp. lactis F1 Nis+ strain; lane 7, L. lactis subsp. lactis NCFB 1402 Nis+ strain.