Comparison of metabolic activities between Piromyces citronii, an equine fungal species, and Piromyces communis, a ruminal species

Abstract

Four strains of Piromyces isolated from the rumen of fistulated sheep and cattle and from the caecum of fistulated donkeys and ponies were compared for their ability to grow on glucose and cellobiose, to digest cellulose and for the end-products of their fermentation. Two main differences appeared between the ruminal and caecal fungi. The equine strains grew more rapidly than the ruminal strains on glucose and cellobiose and did not produce lactate. The four strains had a typical mixed-acid fermentation. The ruminal strains mainly produced formate, acetate, lactate, ethanol and the equine strain produced only formate, acetate and ethanol. Small amounts of malate and succinate and traces of fumarate were also detected. The donkey strains degraded cellulose more rapidly and to a greater extent than the other strains.