Fungal partnerships stimulate growth of Termitomyces clypeatus stalk mycelium in vitro

The symbiotic relationship between termites and fungi, which allows the termite to digest cellulose-rich food sources, is poorly understood. In this study, in vitro mixed symbiotic relationships between and fungi isolated from individual fungus-comb communities using a culture-dependent method were analyzed. Twenty-day-old stalk cultures of three isolates were co-cultured with cellulase-producing fungi on potato dextrose agar. The high cellulase-producing fungal isolate no. 18, which showed 99 % ITS sequence identity to endophyte isolate 2171 (EU687039), increased growth of 18/50 by 85.7 %. The high xylanase-producing isolate no. 13, which showed 88 % ITS sequence identity to isolate L06 (HQ115662), stimulated 18/50 growth by 58.6 %. The high cellulase- and xylanase-producing isolate no. 50, which showed 90 % ITS sequence identity to the fungal endophyte isolate 2196 (EU687056), improved 18/50 growth by 45.7 %. A sp. promoted the growth of 18/50 and 20/50 by 45.7 and 44.1 %, respectively, and that of 19/50 by 10.6 %. These results indicated the most beneficial potential partnership of might involve cellulase-producing fungi isolated from the same ecological niche. The sp. is a potential partner of but is likely to be less common than cellulase-producing fungi isolated from fungus combs owing to the lower host specificity of the sp. This study provides an interesting method to culture using an in vitro mixed culture method for production of fruiting bodies in the future.