Survival of anaerobic fungi in feces, in saliva, and in pure culture

Abstract

Anaerobic fungi were isolated from the feces of British sheep, the feces of Ethiopian sheep and Ethiopian cattle, and the feces (collected at London Zoo) of 11 other herbivorous mammals (Arabian oryx, Asian elephant, bactrian camel, black rhinoceros, bongo, common zebra, greater kudu, gaur, llama, roan antelope, and vicuna). Anaerobic fungi could not be isolated from moist sheep feces (kept in plastic bags) that had been stored in air at 20 or 39°C for 1 day or longer. However, they were isolated from dried sheep feces (dried in air at 20 or 39°C) that had been stored in air at 20 or 39°C up to 128 days, and from sun-baked and dry feces of Ethiopian sheep and cattle. Anaerobic fungi were also isolated from sheep saliva that had been stored in air at 39°C up to 8 h. When Neocallimastix sp., isolate R1 (an anaerobic fungus isolated from the rumen of sheep), was grown in anaerobic culture at 39°C, it remained viable for 5 days in medium containing glucose and for 15 days in a medium containing wheat straw. Cultures of Neocallimastix sp., isolate R1, grown anaerobically in glucose-containing defined medium for 3 days remained viable up to 14 h after they had been aerated and then stored in air at 39°C. The R1 isolate also survived up to 18 h in colonized straw particles that had been removed from anaerobic cultures and then dried and stored in air at 20°C. The results are discussed in relation to the survival of obligately anaerobic fungi in nature and the transfer of anaerobic fungi between animals.