EVALUATION OF 3 METHODS OF PRESERVATION FOR ANAEROBIC-BACTERIA

Three methods of preservation of bacteria were studied observing the v iability and stability of some morphological and biochemical character istics of Bacteroides fragilis, Clostridium perfringens, C. difficile, Fusobacterium nucleatum, Peptostreptococcus sp and Prevotella melanin ogenica (B. melaninogenicus) strains. After periods of storage, B. fra gilis showed the best viability in lyophilization and freezing methods , whereas Clostridium strains were the most resistant bacteria, surviv ing up to one year after lyophilization, freezing or subculturing. Pep tostreptococcus and P. melaninogenica lost the viability at the begini ng of storage, in all methods studied. The stability of colonial, morp hological and physiologic-biochemical aspects of all strains seemed ha ve not been altered throughout this study.