Viability and morphological stability of Absidia strains during long-term maintenance under mineral oil

The viability and morphological features of 23 subcultures of Absidia corym bifera, 7 of Absidia ramosa and 7 of Absidia blakesleeana that were preserv ed in potato dextrose agar (PDA) under sterile mineral oil at room temperat ure in the Fungal Culture Collection of Institute Oswaldo Cruz for periods ranging from 3 to 44 years were examined. The subcultures were transferred to the same culture medium (PDA) on which they were preserved. Permanent pr eparations were made to check the identity of all viable subcultures. The i dentity was confirmed by comparing the material under study with published descriptions. Eighty one percent (81%) of the subcultures with different da tes duration of preservation was viable under oil and maintained characteri stics for species delineation whereas only 5% were dead and 14% were lost b y contamination. This indicates that maintenance under mineral oil is an ef ficient technique for ensuring viability; morphological stabilities and spo res formation of Absidia spp. strains during long-term storage/maintenance in culture collections.