Variation in the Microbiomes of the Basidiomycete FungiScleroderma citrinum(Pers.) andPisolithus arhizus(Pers.): a tale of two saprotrophs

Abstract

In this study we used high throughput DNA sequencing and ICP-MS to compare the microbiome of the common earthball fungus,Scleroderma citrinum(Pers.) to that of its sister taxon in the Sclerodermataceae,Pisolithus arhizus(Scop.). ICP-MS analysis demonstrates thatS. citrinumis enriched in silica, sulfur and zinc relative toP. arhizus, whileP. arhizusis enriched in arsenic, calcium, cadmium, cobalt, copper, lithium, magnesium, molybdenum, nickel, potassium and vanadium. Statistical analysis of molecular data indicates that the microbiome ofP. arhizusis both richer and more diverse than that ofS. citrinum, and that the microbiomes are significantly different with that ofS. citrinumbeing enriched in Cyanobacteria represented by the chloroplast of a photosynthetic, cryptoendolithic red alga, Saccharibacteria (TM-7), and Planctomycetes, while that ofP. arhizusis enriched in Gemmatimonadetes, Latescibacteria, Elusomicrobia, and Tectomicrobia. Further, theP. arhizusmicrobiome is enriched in anaerobes relatives to that ofS. citrinum, probably reflecting anaerobic zones previously measured inP. arhizus. Together, the data indicate diverse microbiomes comprised of aromatic hydrocarbon-degrading, metal- and radiotolerant bacteria, indicating that these fungi may provide a rich source of novel microbes suitable for bioremediation strategies.