Utilization of Major Detrital Substrates by Dark-Septate, Root Endophytes

Utilization of major forms of carbon, nitrogen and phosphorus commonly present in plant litter and detritus was determined for cultures of Phialophora finlandia, Phialocephala fortinii and five dark-septate, root endophyte isolates from alpine plant communities. All cultures utilized cellulose, laminarin, starch and xylan as sole carbon source. Protein and ribonucleic acids were hydrolyzed by all cultures as sole nitrogen and phosphorus sources, respectively. The fatty acid ester, Tween 40, was hydrolyzed by all cultures. None of the cultures decolorized two polymeric dyes used as presumptive tests for lignolytic activity. These hydrolytic capabilities suggest that these dark-septate root endophytes, either as biotrophs or saprotrophs, are able to access major organic detrital nutrient pools.