The challenge for identifying the fungi living inside mushrooms: the case of truffle inhabiting mycelia

Abstract

The Tuber ascomata (truffles) are a microhabitat for bacteria, viruses, and fungi (yeasts and filamentous fungi). In this survey, we tried to develop a method that would make it possible to define the mycobiome of the truffle-inhabiting filamentous fungi using culture independent molecular methods. The nested quantitative Real-Time PCR allowed us to demonstrate that each truffle is home to multiple species of filamentous fungi and that their DNA is present within the healthy ascoma at the ratio of 10⁻⁶ compared to that of the truffle. Probably due to their insignificant presence, Denaturing Gradient Gel Electrophoresis of the amplification of ITS amplicons showed only those of the host. Based on the results, the possibilities of being able to detect the fungicolous fungi present in very small amounts within a fungal host are discussed.

Keywords:

• DGGE
• real time PCR
• nested qPCR
• symbiosis
• truffle mycobiome

Acknowledgments

We are grateful to Silvio Guardiani, Domenico Marinucci, Marilena Oddis and Carmine Visca for providing us with truffles studied here; to Federica Matteucci for her helpful advice in conducting the DGGE analysis.