CHARACTERIZATION OF STRAINS OF LEUCONOSTOC-MESENTEROIDES BY ANALYSIS OF SOLUBLE WHOLE-CELL PROTEIN PATTERN, DNA-FINGERPRINTING AND RESTRICTION OF RIBOSOMAL DNA

Of 215 leuconostocs isolated from field grass, natural whey cultures a nd water-buffalo milk, 178 were identified as Leuconostoc mesenteroide s ssp. mesenteroides while 37 strains could not be identified. Biochem ical characterization allowed seven groups to be defined. Representati ve strains of each group and different habitat and nine reference stra ins were selected for further analyses. Protein profiles appeared suit able for species discrimination, but did not differentiate between the three subspecies of Leuc. mesenteroides. The technique also showed so me differences among equivocal strains. DNA fingerprinting for most st rains of Leuc. mesenteroides ssp. mesenteroides examined showed a diff erent restriction pattern from that of the type strain. Ribotyping was not useful for discriminating species and subspecies of the genus Leu conostoc: Leuc. mesenteroides ssp. mesenteroides and ssp. dextranicum showed the same ribopattern as Leuc. lactis while Leuc. mesenteroides ssp, cremoris exhibited a pattern distinct from all the other species examined. On the basis of ARDRA-PCR, two main groups could be distingu ished: the larger group included Leuc, mesenteroides, Leuc. lactis, Le uc. pseudomesenteroides and some unidentifiable strains; the second on e included Leuc. citreum, Leuc. fallax, Weissella paramesenteroides an d some unidentified strains.