Isolation of bacteria from ectomycorrhizae of Tuber aestivum Vittad

Milana Gryndler,Hana Hršelová

doi:10.5586/am.2012.018

Abstract

Fifteen different cultivation media were used to isolate bacteria with the idea to obtain taxa specifically associated with ectomycorrhizae of Tuber aestivum. Ectomycorrhizae were collected at the sampling points previously analyzed for bacterial molecular diversity. We isolated 183 bacterial strains and identified them on the basis of the partial sequence of 16S rDNA. Out of these isolates, only 4 corresponded to operational taxonomic units significantly associated with T. aestivum ectomycorrhizae in previous molecular study. Preliminary study of the effect of 12 selected isolates on growth of T. aestivum mycelium showed no stimulation and one isolate induced the damage of hyphae. Different isolation strategy has to be developed to increase the probability of cultivation of potentially important components of T. aestivum mycorrhizosphere.

Highlights

Truffles have been highly appreciated as a special culinary ingredient, being highly priced on the markets
Based on the partial sequence of the 16S rDNA, they belong to 6 bacterial orders: Actinomycetales (139 isolates), Burkholderiales (4 isolates), Enterobacteriales (1 isolate), Pseudomonadales (2 isolates), Rhizobiales (33 isolates) and Xanthomonadales (4 isolates)
In spite of extensive effort during the isolation of the bacteria from ectomycorrhizae of T. aestivum, we were able to cultivate the members of 6 bacterial orders

Summary

Introduction

Truffles have been highly appreciated as a special culinary ingredient, being highly priced on the markets. Truffles are ectomycorrhizal Ascomycota deriving significant portion, if not all, of their carbon nutrition from a host tree via specialized communication organs, ectomycorrhizae. The soil space directly affected by ectomycorrhizae is called mycorrhizosphere (Linderman 1988) and is characterized by high biological activity (Chalot, Brun 1998). Presence of some bacteria may enhance the formation of ectomycorrhizal structures on the roots and was shown to change gene expression of the ectomycorrhizal fungal hyphae (Deveau et al 2007).

Methods

Results

Conclusion