Substrate-utilization Properties of Termitomyces Culture Isolated from Termite Mound in the Great Rift Valley Region of Ethiopia

Abstract

Termites of the subfamily Macrotermitinae are known to live in an obligate symbiosis with Termitomyces mushrooms, although the exact benefit of the association is still debating. Termitomyces are believed to degrade lignocelluloses into smaller units which then can be used by the fungus-growing termites. In this study, extracts of the termite comb showed strong xylanase activity (8.27 ± 0.14 unit per g of dried comb) with no cellulase activity. Termite comb and wheat bran supported the growth of Termitomyces culture in solid state fermentations, in which culture-extracts showed strong xylanase activities (52.25 ± 1.98 and 37.38 ± 1.09 units per g of dried culture, respectively), yet no cellulase activities were detected. Furthermore, we observed that Termitomyces cultures were unable to grow on pure cellulose (Avicell). Hence, the isolated Termitomyces may be incapable of using cellulose in the studied termite nest. As the absence of cellulase activities in the extracts (both comb and culture) and the inability to grow on pure cellulose (Avicell) are unpredicted properties of the fungus, results of this study may add some important data on the ongoing debate for the association between Macrotermitinae termites and Termitomyces mushrooms.

Keywords: Termitomyces, termite comb, xylanase, cellulase, Fungus-growing termites