First Report on Truffle-Inhabiting Fungi and Metagenomic Communities of Tuber Aestivum Collected in Russia

Abstract

Truffles are one of the least studied groups of fungi in terms of their biological and biotechnological aspects. This study aimed to isolate truffle-inhabiting fungi and assess the metagenomic communities of the most common Russian summer truffle, Tuber aestivum. This study is the first to characterize the biodiversity of prokaryotic and eukaryotic organisms living in the truffle T. aestivum using molecular analysis and sequencing. Plant pathogens involved in a symbiotic relationship with truffles were identified by sequencing the hypervariable fragments of the 16S rRNA and 18S rRNA genes. In addition, some strains of fungal symbionts and likely pathogens were isolated and recognized for the first time from the truffles. This study also compared and characterized the general diversity and distribution of microbial taxa of T. aestivum collected in Russia and Europe. The results revealed that the Russian and European truffle study materials demonstrated high similarity. In addition to the truffles, representatives of bacteria, fungi, and protists were found in the fruiting bodies. Many of these prokaryotic and eukaryotic species inhabiting truffles might influence them, help them form mycorrhizae with trees, and regulate biological processes. Thus, truffles are interesting and promising sources for modern biotechnological and agricultural studies.

Effect of truffle extracts on growth ofChlorella vulgaris

“…This may suggest that the volatile organic compounds produced by truffle symbiont bacteria may stimulate growth of C. vulgaris . The microbial composition of Russian black truffles collected in Sochi has been described earlier in our studies [10]. The primary analysis detected at least 45 bacterial organisms with unique OTUs, and 22 fungal organisms as regular inhabitants of Tuber sp.…”

“…The primary analysis detected at least 45 bacterial organisms with unique OTUs, and 22 fungal organisms as regular inhabitants of Tuber sp. fruiting bodies [10,9,13,26].…”

“…Once released from the gastrointestinal tract of animals, spores develop into mycelium, which forms the ectomycorrhizal association with the roots of host trees [5,6,7,8]. Next partners in the symbiosis between the fungus and the host tree are bacterial communities [9,10]. Fruiting bodies of truffles are a home for many bacterial species, whose role in the fungal association is unclear.…”

“…For example, bacteria Bradyrhizobium sp. are the main truffle-associated bacteria involved with the truffle species studied [10,11,12]. Bacteria associated with fruiting bodies of truffles often act as assistants of mycelial growth, adaptation, forming of fruiting bodies, and other processes [10].…”

“…are the main truffle-associated bacteria involved with the truffle species studied [10,11,12]. Bacteria associated with fruiting bodies of truffles often act as assistants of mycelial growth, adaptation, forming of fruiting bodies, and other processes [10]. Also, symbiont bacteria can synthesize volatile organic compounds that contribute to the truffle flavor [13,14].…”