Some fungi in the Chytridiomycota can assimilate both inorganic and organic sources of nitrogen

Seventeen fungi in the Chytridiomycota were tested for their ability to use nitrate as a sole source of nitrogen in solid medium, and various organic and inorganic sources of nitrogen in liquid media. Since fourteen of the seventeen isolates grew well on solid chytrid synthetic medium (CSM) with nitrate as the sole source of nitrogen, this medium appears to be excellent for maintaining many of these fungi in culture. Growth was observed in liquid media containing nitrate, ammonium, urea, aspartate, alanine, phenylalanine, histidine and arginine as nitrogen sources. The results did not show clear patterns of nitrogen requirements within the orders tested. However, it does appear that the nitrogen requirements among zoosporic fungi are variable. Single amino acids were poor sources of both carbon and nitrogen in all fungi tested. Furthermore, since glucose and thiamine are the only organic compounds in CSM with nitrate, these results suggest that many of these fungi are capable of growth in the soil under field conditions with very little organic matter.