HETEROGENEITY OF PLANT-ASSOCIATED STREPTOCOCCI AS CHARACTERIZED BY PHENOTYPIC FEATURES AND RESTRICTION ANALYSIS OF PCR-AMPLIFIED 16S RDNA

Thirty-five strains of streptococci isolated from forage grasses mere examined by restriction analysis of PCR-amplified 16S rDNA. Using a se t of seven endonucleases, five 16S rDNA genotypes were obtained. The i solates could be identified as belonging to the species Enterococcus f aecium, Ent. mundtii, Ent. faecalis, Ent. casseliflavus and Lactococcu s lactis ssp. lactis, respectively. To assign the isolates to one of t hese species, digestion with the endonuclease HinfI was sufficient. Da ta obtained from whole-cell protein analysis were in accordance with t he species identification. Additionally, three of the five species fou nd were subdivided into two related subgroups. Both methods are suitab le for a rapid and unequivocal identification of plant-associated stre ptococci. The phenotypic characters showed a high diversity and were i n some cases contrary to the expected features usually given in genus and species descriptions. The results demonstrated the close relatedne ss of the determined species in contrast to their high phenotypic hete rogeneity.