Bacteria associated to fruit bodies of the ecto-mycorrhizal fungus Tuber borchii Vittad.

A microbial population was isolated from young sporocarps of Tuber borchii Vittad. to study its possible role in ascus opening. The bacteria in the sp orocarps had a mean value of 10(6) CFU/g and were generally found in quanti ties higher than that found in the bulk soil (10(3)). In the sporocarps exa mined the predominant bacteria were Pseudomonas fluorescens (30% of the tot al population) and spore-forming, gram-positive, bacteria (15% of total). T hese bacterial species were tested to evaluate their capacity to degrade ce llulose and chitin, the most important components of the hyphal walls. Ultr astructural examination of the tested sporocarps revealed the presence of b acteria in the interhyphal space, a portion of which were embedded in the a scus wall. It is suggested that the presence of Pseudomonas strains and Bac illaceae in T. borchii Vittad. sporocarps could be related to their chitino lytic and cellulolytic activities, which could in turn be involved in ascus opening and, perhaps, in spore germination.